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Posted to commits@hugegraph.apache.org by vg...@apache.org on 2024/02/20 13:55:36 UTC

(incubator-hugegraph) branch pd-store updated (d61aaae44 -> 5551ec17f)

This is an automated email from the ASF dual-hosted git repository.

vgalaxies pushed a change to branch pd-store
in repository https://gitbox.apache.org/repos/asf/incubator-hugegraph.git


    from d61aaae44 fix(pd-store): correct license in hugegraph-pd (#2446)
     new 721111d11 fix: format and clean code in dist and example modules (#2441)
     new 960b7330f fix: format and clean code in core module (#2440)
     new 5551ec17f fix: format and clean code in modules (#2439)

The 3 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails.  The revisions
listed as "add" were already present in the repository and have only
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Summary of changes:
 .../main/java/org/apache/hugegraph/api/API.java    |  15 +-
 .../org/apache/hugegraph/api/arthas/ArthasAPI.java |   1 -
 .../org/apache/hugegraph/api/auth/AccessAPI.java   |  36 +-
 .../org/apache/hugegraph/api/auth/BelongAPI.java   |  34 +-
 .../org/apache/hugegraph/api/auth/GroupAPI.java    |  34 +-
 .../org/apache/hugegraph/api/auth/ProjectAPI.java  |  36 +-
 .../org/apache/hugegraph/api/auth/TargetAPI.java   |  32 +-
 .../org/apache/hugegraph/api/auth/UserAPI.java     |  36 +-
 .../org/apache/hugegraph/api/cypher/CypherAPI.java |   1 -
 .../apache/hugegraph/api/cypher/CypherClient.java  |  26 +-
 .../apache/hugegraph/api/cypher/CypherModel.java   |   2 +
 .../hugegraph/api/filter/AuthenticationFilter.java |  10 +-
 .../hugegraph/api/filter/CompressInterceptor.java  |  19 +-
 .../api/filter/DecompressInterceptor.java          |   3 +-
 .../hugegraph/api/filter/ExceptionFilter.java      |  52 +--
 .../hugegraph/api/filter/LoadDetectFilter.java     |  35 +-
 .../hugegraph/api/filter/LoadReleaseFilter.java    |   4 +-
 .../hugegraph/api/filter/RedirectFilter.java       |   1 +
 .../apache/hugegraph/api/filter/StatusFilter.java  |   3 +-
 .../org/apache/hugegraph/api/graph/BatchAPI.java   |  37 +-
 .../org/apache/hugegraph/api/graph/EdgeAPI.java    | 166 ++++----
 .../org/apache/hugegraph/api/graph/VertexAPI.java  |  98 ++---
 .../api/gremlin/AbstractJerseyRestClient.java      |   2 +-
 .../apache/hugegraph/api/gremlin/GremlinAPI.java   |  16 +-
 .../hugegraph/api/gremlin/GremlinQueryAPI.java     |   1 +
 .../org/apache/hugegraph/api/job/AlgorithmAPI.java |   1 -
 .../org/apache/hugegraph/api/job/GremlinAPI.java   |   4 +-
 .../java/org/apache/hugegraph/api/job/TaskAPI.java |  12 +-
 .../apache/hugegraph/api/metrics/MetricsAPI.java   |   1 -
 .../apache/hugegraph/api/profile/GraphsAPI.java    |  48 +--
 .../apache/hugegraph/api/profile/ProfileAPI.java   |  31 +-
 .../apache/hugegraph/api/profile/VersionAPI.java   |  19 +-
 .../hugegraph/api/profile/WhiteIpListAPI.java      |   6 +-
 .../org/apache/hugegraph/api/raft/RaftAPI.java     |  34 +-
 .../hugegraph/api/traversers/AdamicAdarAPI.java    |  21 +-
 .../apache/hugegraph/api/traversers/CountAPI.java  |  22 +-
 .../hugegraph/api/traversers/EdgeExistenceAPI.java |   1 -
 .../hugegraph/api/traversers/NeighborRankAPI.java  |  22 +-
 .../hugegraph/api/traversers/PersonalRankAPI.java  |  20 +-
 .../api/traversers/ResourceAllocationAPI.java      |  21 +-
 .../apache/hugegraph/api/traversers/Vertices.java  |  10 +-
 .../hugegraph/api/variables/VariablesAPI.java      |  22 +-
 .../apache/hugegraph/auth/ConfigAuthenticator.java |   5 +-
 .../hugegraph/auth/ContextGremlinServer.java       |   8 +-
 .../apache/hugegraph/auth/HugeAuthenticator.java   |  10 +-
 .../hugegraph/auth/HugeFactoryAuthProxy.java       | 441 +++++++++++++++++----
 .../apache/hugegraph/auth/HugeGraphAuthProxy.java  |  62 +--
 .../hugegraph/auth/StandardAuthenticator.java      |   7 +-
 .../hugegraph/auth/WsAndHttpBasicAuthHandler.java  |  10 +-
 .../org/apache/hugegraph/config/ServerOptions.java |  48 +--
 .../org/apache/hugegraph/core/GraphManager.java    |  16 +-
 .../apache/hugegraph/define/UpdateStrategy.java    |   9 +-
 .../apache/hugegraph/metrics/MetricsModule.java    |   2 +-
 .../apache/hugegraph/metrics/ServerReporter.java   |   5 +-
 .../apache/hugegraph/metrics/SystemMetrics.java    |   5 +-
 .../hugegraph/opencypher/CypherOpProcessor.java    |  38 +-
 .../apache/hugegraph/opencypher/CypherPlugin.java  |  28 +-
 .../hugegraph/rpc/RpcClientProviderWithAuth.java   |   3 +-
 .../apache/hugegraph/server/ApplicationConfig.java |  32 +-
 .../org/apache/hugegraph/server/RestServer.java    |  21 +-
 .../store/cassandra/CassandraEntryIterator.java    |   2 +-
 .../backend/store/cassandra/CassandraMetrics.java  |   6 +-
 .../store/cassandra/CassandraSerializer.java       |   1 +
 .../store/cassandra/CassandraSessionPool.java      |   1 +
 .../backend/store/cassandra/CassandraShard.java    |  42 +-
 .../backend/store/cassandra/CassandraStore.java    |  48 ++-
 .../backend/store/cassandra/CassandraTable.java    |  35 +-
 .../backend/store/cassandra/CassandraTables.java   |   8 +-
 .../java/org/apache/hugegraph/HugeFactory.java     |   3 +-
 .../main/java/org/apache/hugegraph/HugeGraph.java  |   6 +-
 .../java/org/apache/hugegraph/HugeGraphParams.java |   9 +-
 .../org/apache/hugegraph/StandardHugeGraph.java    |  72 ++--
 .../apache/hugegraph/analyzer/AnalyzerFactory.java |   6 +-
 .../apache/hugegraph/analyzer/AnsjAnalyzer.java    |   8 +-
 .../apache/hugegraph/analyzer/HanLPAnalyzer.java   |  23 +-
 .../org/apache/hugegraph/analyzer/IKAnalyzer.java  |   8 +-
 .../apache/hugegraph/analyzer/JcsegAnalyzer.java   |   8 +-
 .../apache/hugegraph/analyzer/JiebaAnalyzer.java   |   5 +-
 .../apache/hugegraph/analyzer/MMSeg4JAnalyzer.java |   7 +-
 .../apache/hugegraph/analyzer/SmartCNAnalyzer.java |   5 +-
 .../org/apache/hugegraph/auth/AuthManager.java     |   2 +-
 .../org/apache/hugegraph/auth/EntityManager.java   |  16 +-
 .../java/org/apache/hugegraph/auth/HugeAccess.java |   7 +-
 .../java/org/apache/hugegraph/auth/HugeBelong.java |  15 +-
 .../java/org/apache/hugegraph/auth/HugeGroup.java  |   9 +-
 .../org/apache/hugegraph/auth/HugeProject.java     |   7 +-
 .../org/apache/hugegraph/auth/HugeResource.java    |  19 +-
 .../java/org/apache/hugegraph/auth/HugeTarget.java |   9 +-
 .../java/org/apache/hugegraph/auth/HugeUser.java   |   7 +-
 .../apache/hugegraph/auth/RelationshipManager.java |  18 +-
 .../org/apache/hugegraph/auth/ResourceObject.java  |   2 +-
 .../org/apache/hugegraph/auth/ResourceType.java    |   9 +-
 .../org/apache/hugegraph/auth/RolePermission.java  |  26 +-
 .../org/apache/hugegraph/auth/SchemaDefine.java    |  12 +-
 .../apache/hugegraph/auth/StandardAuthManager.java |  16 +-
 .../org/apache/hugegraph/auth/TokenGenerator.java  |   2 +-
 .../apache/hugegraph/backend/BackendException.java |   2 +-
 .../hugegraph/backend/cache/AbstractCache.java     |   5 +-
 .../hugegraph/backend/cache/CacheManager.java      |   7 +-
 .../hugegraph/backend/cache/CacheNotifier.java     |   8 +-
 .../backend/cache/CachedBackendStore.java          |   2 +-
 .../backend/cache/CachedGraphTransaction.java      |   9 +-
 .../backend/cache/CachedSchemaTransaction.java     |   9 +-
 .../hugegraph/backend/cache/OffheapCache.java      |  23 +-
 .../apache/hugegraph/backend/cache/RamCache.java   |  12 +-
 .../org/apache/hugegraph/backend/id/EdgeId.java    |  40 +-
 .../org/apache/hugegraph/backend/id/IdUtil.java    |   1 -
 .../hugegraph/backend/id/SnowflakeIdGenerator.java |  13 +-
 .../hugegraph/backend/id/SplicingIdGenerator.java  |  18 +-
 .../apache/hugegraph/backend/page/IdHolder.java    |   7 +-
 .../hugegraph/backend/page/PageEntryIterator.java  |   3 +-
 .../org/apache/hugegraph/backend/page/PageIds.java |   1 +
 .../apache/hugegraph/backend/page/QueryList.java   |  26 +-
 .../backend/page/SortByCountIdHolderList.java      |   3 +-
 .../backend/query/BatchConditionQuery.java         |   2 +-
 .../apache/hugegraph/backend/query/Condition.java  |  44 +-
 .../hugegraph/backend/query/ConditionQuery.java    |  19 +-
 .../backend/query/ConditionQueryFlatten.java       |   2 +-
 .../apache/hugegraph/backend/query/IdQuery.java    |   3 +-
 .../org/apache/hugegraph/backend/query/Query.java  |   8 +-
 .../hugegraph/backend/query/QueryResults.java      |  13 +-
 .../backend/serializer/AbstractSerializer.java     |   8 +-
 .../serializer/BinaryScatterSerializer.java        |   2 +-
 .../backend/serializer/BinarySerializer.java       |  29 +-
 .../hugegraph/backend/serializer/BytesBuffer.java  |  16 +-
 .../backend/serializer/GraphSerializer.java        |   3 +-
 .../backend/serializer/MergeIterator.java          |   4 +-
 .../backend/serializer/SerializerFactory.java      |   2 +-
 .../backend/serializer/TableBackendEntry.java      |   1 -
 .../backend/serializer/TableSerializer.java        |  21 +-
 .../backend/serializer/TextBackendEntry.java       |   3 +-
 .../backend/serializer/TextSerializer.java         |  27 +-
 .../backend/store/AbstractBackendStore.java        |   8 +-
 .../store/AbstractBackendStoreProvider.java        |  10 +-
 .../backend/store/BackendEntryIterator.java        |   1 -
 .../hugegraph/backend/store/BackendMutation.java   |  41 +-
 .../backend/store/BackendProviderFactory.java      |   7 +-
 .../backend/store/BackendSessionPool.java          |   5 +-
 .../hugegraph/backend/store/BackendStore.java      |   9 +-
 .../hugegraph/backend/store/BackendStoreInfo.java  |   3 +-
 .../backend/store/BackendStoreProvider.java        |   3 +-
 .../hugegraph/backend/store/BackendTable.java      |   4 +-
 .../hugegraph/backend/store/TableDefine.java       |   1 +
 .../backend/store/memory/InMemoryDBStore.java      |  12 +-
 .../store/memory/InMemoryDBStoreProvider.java      |   2 +-
 .../backend/store/memory/InMemoryDBTable.java      |  24 +-
 .../backend/store/memory/InMemoryDBTables.java     |  51 +--
 .../backend/store/memory/InMemoryMetrics.java      |   1 +
 .../backend/store/raft/RaftBackendStore.java       |  18 +-
 .../store/raft/RaftBackendStoreProvider.java       |   7 +-
 .../hugegraph/backend/store/raft/RaftClosure.java  |   4 +-
 .../hugegraph/backend/store/raft/RaftContext.java  |  44 +-
 .../backend/store/raft/RaftException.java          |   2 +-
 .../backend/store/raft/RaftGroupManagerImpl.java   |  20 +-
 .../hugegraph/backend/store/raft/RaftNode.java     |  26 +-
 .../hugegraph/backend/store/raft/RaftResult.java   |   3 +-
 .../backend/store/raft/StoreSerializer.java        |   2 +-
 .../backend/store/raft/StoreSnapshotFile.java      |   2 +-
 .../backend/store/raft/StoreStateMachine.java      |  22 +-
 .../raft/compress/CompressStrategyManager.java     |   6 +-
 .../raft/compress/ParallelCompressStrategy.java    |  16 +-
 .../backend/store/raft/rpc/AddPeerProcessor.java   |  11 +-
 .../backend/store/raft/rpc/ListPeersProcessor.java |  12 +-
 .../store/raft/rpc/RemovePeerProcessor.java        |  11 +-
 .../backend/store/raft/rpc/RpcForwarder.java       |  41 +-
 .../backend/store/raft/rpc/SetLeaderProcessor.java |   4 +-
 .../store/raft/rpc/StoreCommandProcessor.java      |  10 +-
 .../hugegraph/backend/store/ram/RamTable.java      |   8 +-
 .../hugegraph/backend/tx/AbstractTransaction.java  |  16 +-
 .../backend/tx/GraphIndexTransaction.java          | 145 +++----
 .../hugegraph/backend/tx/GraphTransaction.java     |  93 ++---
 .../hugegraph/backend/tx/IndexableTransaction.java |   4 +-
 .../backend/tx/SchemaIndexTransaction.java         |   7 +-
 .../hugegraph/backend/tx/SchemaTransaction.java    |  39 +-
 .../org/apache/hugegraph/config/CoreOptions.java   |  40 +-
 .../apache/hugegraph/io/HugeGraphIoRegistry.java   |   2 +-
 .../apache/hugegraph/io/HugeGraphSONModule.java    |  65 ++-
 .../org/apache/hugegraph/io/HugeGryoModule.java    |   2 +-
 .../java/org/apache/hugegraph/job/ComputerJob.java |   2 +-
 .../apache/hugegraph/job/EphemeralJobBuilder.java  |   2 +-
 .../java/org/apache/hugegraph/job/GremlinJob.java  |  12 +-
 .../java/org/apache/hugegraph/job/JobBuilder.java  |   2 +-
 .../hugegraph/job/algorithm/AbstractAlgorithm.java |  30 +-
 .../hugegraph/job/algorithm/AlgorithmPool.java     |   6 +-
 .../hugegraph/job/algorithm/BfsTraverser.java      |   7 +-
 .../apache/hugegraph/job/algorithm/Consumers.java  |   5 +-
 .../job/algorithm/CountEdgeAlgorithm.java          |   3 +-
 .../job/algorithm/CountVertexAlgorithm.java        |   3 +-
 .../job/algorithm/SubgraphStatAlgorithm.java       |  14 +-
 .../job/algorithm/cent/AbstractCentAlgorithm.java  |  53 ++-
 .../cent/BetweennessCentralityAlgorithm.java       |  13 +-
 .../cent/BetweennessCentralityAlgorithmV2.java     |   5 +-
 .../cent/ClosenessCentralityAlgorithm.java         |   9 +-
 .../cent/ClosenessCentralityAlgorithmV2.java       |   8 +-
 .../algorithm/cent/DegreeCentralityAlgorithm.java  |   5 +-
 .../cent/EigenvectorCentralityAlgorithm.java       |   5 +-
 .../algorithm/cent/StressCentralityAlgorithm.java  |   7 +-
 .../cent/StressCentralityAlgorithmV2.java          |   3 +-
 .../comm/ClusterCoefficientAlgorithm.java          |   2 +-
 .../job/algorithm/comm/KCoreAlgorithm.java         |  15 +-
 .../job/algorithm/comm/LouvainAlgorithm.java       |   4 +-
 .../job/algorithm/comm/LouvainTraverser.java       |  38 +-
 .../hugegraph/job/algorithm/comm/LpaAlgorithm.java |   6 +-
 .../job/algorithm/comm/WeakConnectedComponent.java |  21 +-
 .../job/algorithm/rank/PageRankAlgorithm.java      |  31 +-
 .../similarity/FusiformSimilarityAlgorithm.java    |  15 +-
 .../hugegraph/job/computer/AbstractComputer.java   |  20 +-
 .../hugegraph/job/computer/LouvainComputer.java    |   5 +-
 .../apache/hugegraph/job/computer/LpaComputer.java |   3 +-
 .../hugegraph/job/computer/PageRankComputer.java   |   3 +-
 .../job/computer/TriangleCountComputer.java        |   2 +-
 .../computer/WeakConnectedComponentComputer.java   |   2 +-
 .../hugegraph/job/schema/EdgeLabelRemoveJob.java   |   3 +-
 .../hugegraph/job/schema/IndexLabelRebuildJob.java |  16 +-
 .../hugegraph/job/schema/IndexLabelRemoveJob.java  |   2 +-
 .../job/schema/OlapPropertyKeyClearJob.java        |   2 +-
 .../org/apache/hugegraph/job/schema/SchemaJob.java |  27 +-
 .../hugegraph/job/schema/VertexLabelRemoveJob.java |  11 +-
 .../job/system/DeleteExpiredElementJob.java        |   2 +-
 .../job/system/DeleteExpiredIndexJob.java          |   4 +-
 .../hugegraph/job/system/DeleteExpiredJob.java     |   9 +-
 .../apache/hugegraph/job/system/JobCounters.java   |   4 +-
 .../hugegraph/masterelection/ClusterRole.java      |   8 +-
 .../masterelection/RoleElectionOptions.java        |   2 +-
 .../masterelection/StandardRoleListener.java       |   2 +-
 .../hugegraph/plugin/HugeGraphGremlinPlugin.java   |   6 +-
 .../apache/hugegraph/plugin/HugeGraphPlugin.java   |   2 +-
 .../org/apache/hugegraph/schema/EdgeLabel.java     |   6 +-
 .../org/apache/hugegraph/schema/IndexLabel.java    |  19 +-
 .../org/apache/hugegraph/schema/PropertyKey.java   |  27 +-
 .../org/apache/hugegraph/schema/SchemaElement.java |  10 +-
 .../org/apache/hugegraph/schema/SchemaLabel.java   |  15 +-
 .../org/apache/hugegraph/schema/SchemaManager.java |  22 +-
 .../java/org/apache/hugegraph/schema/Userdata.java |   6 +-
 .../org/apache/hugegraph/schema/VertexLabel.java   |   2 +-
 .../hugegraph/schema/builder/AbstractBuilder.java  |   6 +-
 .../hugegraph/schema/builder/EdgeLabelBuilder.java |  55 +--
 .../schema/builder/IndexLabelBuilder.java          |  11 +-
 .../schema/builder/PropertyKeyBuilder.java         |  48 ++-
 .../schema/builder/VertexLabelBuilder.java         |  47 +--
 .../hugegraph/security/HugeSecurityManager.java    |  56 ++-
 .../org/apache/hugegraph/structure/GraphType.java  |   1 +
 .../org/apache/hugegraph/structure/HugeEdge.java   |   8 +-
 .../hugegraph/structure/HugeEdgeProperty.java      |   3 +-
 .../apache/hugegraph/structure/HugeElement.java    |  14 +-
 .../apache/hugegraph/structure/HugeFeatures.java   |  18 +-
 .../org/apache/hugegraph/structure/HugeIndex.java  |   2 +-
 .../apache/hugegraph/structure/HugeProperty.java   |   3 +-
 .../org/apache/hugegraph/structure/HugeVertex.java |  13 +-
 .../hugegraph/structure/HugeVertexProperty.java    |   9 +-
 .../apache/hugegraph/task/EphemeralJobQueue.java   |   6 +-
 .../org/apache/hugegraph/task/HugeServerInfo.java  |  22 +-
 .../java/org/apache/hugegraph/task/HugeTask.java   |  51 ++-
 .../apache/hugegraph/task/ServerInfoManager.java   |   6 +-
 .../hugegraph/task/StandardTaskScheduler.java      |  36 +-
 .../org/apache/hugegraph/task/TaskCallable.java    |   6 +-
 .../org/apache/hugegraph/task/TaskManager.java     |  16 +-
 .../org/apache/hugegraph/task/TaskScheduler.java   |   8 +-
 .../java/org/apache/hugegraph/task/TaskStatus.java |   5 +-
 .../traversal/algorithm/CountTraverser.java        |   5 +-
 .../traversal/algorithm/HugeTraverser.java         |   1 +
 .../traversal/algorithm/NeighborRankTraverser.java |  11 +-
 .../traversal/algorithm/OltpTraverser.java         |   6 +-
 .../traversal/algorithm/PersonalRankTraverser.java |   5 +-
 .../traversal/algorithm/PredictionTraverser.java   |   1 +
 .../traversal/algorithm/ShortestPathTraverser.java |   9 +-
 .../algorithm/records/AbstractRecords.java         |   4 +-
 .../records/DoubleWayMultiPathsRecords.java        |   4 +-
 .../traversal/algorithm/records/KoutRecords.java   |   2 +-
 .../algorithm/records/record/SyncRecord.java       |   2 +-
 .../traversal/algorithm/steps/EdgeStep.java        |   6 +-
 .../traversal/algorithm/steps/RepeatEdgeStep.java  |   1 +
 .../algorithm/steps/WeightedEdgeStep.java          |   1 +
 .../strategy/ConcurrentTraverseStrategy.java       |   2 +-
 .../algorithm/strategy/SingleTraverseStrategy.java |  10 +-
 .../algorithm/strategy/TraverseStrategy.java       |   4 +-
 .../traversal/optimize/HugeCountStep.java          |   8 +-
 .../traversal/optimize/HugeCountStepStrategy.java  |  20 +-
 .../traversal/optimize/HugeGraphStep.java          |   5 +-
 .../traversal/optimize/HugeGraphStepStrategy.java  |   8 +-
 .../traversal/optimize/HugePrimaryKeyStrategy.java |   4 +-
 .../traversal/optimize/HugeScriptTraversal.java    |   4 +-
 .../traversal/optimize/HugeVertexStep.java         |  24 +-
 .../traversal/optimize/HugeVertexStepByBatch.java  |  11 +-
 .../traversal/optimize/HugeVertexStepStrategy.java |  14 +-
 .../hugegraph/traversal/optimize/QueryHolder.java  |   3 +-
 .../traversal/optimize/TraversalUtil.java          |  30 +-
 .../java/org/apache/hugegraph/type/Nameable.java   |   1 +
 .../hugegraph/type/define/CollectionType.java      |   2 +-
 .../org/apache/hugegraph/type/define/DataType.java |  12 +-
 .../apache/hugegraph/type/define/Directions.java   |   8 +-
 .../apache/hugegraph/type/define/IndexType.java    |   2 +-
 .../apache/hugegraph/type/define/SerialEnum.java   |   1 +
 .../org/apache/hugegraph/util/CompressUtil.java    |  13 +-
 .../java/org/apache/hugegraph/util/ConfigUtil.java |  17 +-
 .../java/org/apache/hugegraph/util/Consumers.java  |   2 +-
 .../util/FixedTimerWindowRateLimiter.java          |   2 +-
 .../util/FixedWatchWindowRateLimiter.java          |   4 +-
 .../java/org/apache/hugegraph/util/GZipUtil.java   |   1 -
 .../java/org/apache/hugegraph/util/JsonUtil.java   |  11 +-
 .../java/org/apache/hugegraph/util/KryoUtil.java   |   2 +-
 .../java/org/apache/hugegraph/util/LockUtil.java   |  20 +-
 .../org/apache/hugegraph/util/ParameterUtil.java   |   2 -
 .../org/apache/hugegraph/util/RateLimiter.java     |   3 +
 .../java/org/apache/hugegraph/util/Reflection.java |  26 +-
 .../org/apache/hugegraph/util/StringEncoding.java  |   1 -
 .../util/collection/CollectionFactory.java         |  29 +-
 .../apache/hugegraph/util/collection/IdSet.java    |   9 +-
 .../hugegraph/util/collection/Int2IntsMap.java     |   2 +-
 .../hugegraph/util/collection/IntIterator.java     |   4 +-
 .../apache/hugegraph/util/collection/IntMap.java   |  21 +-
 .../util/collection/IntMapByDynamicHash.java       |  36 +-
 .../apache/hugegraph/util/collection/IntSet.java   |  11 +-
 .../util/collection/ObjectIntMappingFactory.java   |  11 +-
 .../apache/hugegraph/variables/HugeVariables.java  |  15 +-
 hugegraph-server/hugegraph-dist/docker/README.md   |   2 +-
 .../src/assembly/static/conf/gremlin-server.yaml   |  50 +--
 .../src/assembly/static/conf/log4j2.xml            |  26 +-
 .../src/assembly/static/conf/remote-objects.yaml   |   4 +-
 .../assembly/travis/conf-raft1/gremlin-server.yaml |  40 +-
 .../assembly/travis/conf-raft2/gremlin-server.yaml |  40 +-
 .../assembly/travis/conf-raft3/gremlin-server.yaml |  40 +-
 .../hugegraph-dist/src/assembly/travis/maven.xml   |  40 +-
 .../java/org/apache/hugegraph/cmd/ConfDumper.java  |   7 +-
 .../java/org/apache/hugegraph/cmd/InitStore.java   |   5 +-
 .../org/apache/hugegraph/dist/HugeGraphServer.java |   2 +-
 .../apache/hugegraph/dist/HugeGremlinServer.java   |   7 +-
 .../org/apache/hugegraph/dist/HugeRestServer.java  |   3 +-
 .../org/apache/hugegraph/dist/RegisterUtil.java    |  37 +-
 .../hugegraph-dist/src/main/resources/log4j2.xml   |  26 +-
 .../org/apache/hugegraph/example/Example1.java     |  29 +-
 .../org/apache/hugegraph/example/Example2.java     |  43 +-
 .../org/apache/hugegraph/example/Example3.java     |   7 +-
 .../org/apache/hugegraph/example/ExampleUtil.java  |   5 +-
 .../hugegraph/example/GraphOfTheMoviesExample.java | 134 +++----
 .../org/apache/hugegraph/example/PerfExample1.java |   6 +-
 .../org/apache/hugegraph/example/PerfExample2.java |   6 +-
 .../org/apache/hugegraph/example/PerfExample3.java |   7 +-
 .../org/apache/hugegraph/example/PerfExample4.java |   6 +-
 .../apache/hugegraph/example/PerfExampleBase.java  |   7 +-
 .../org/apache/hugegraph/example/TaskExample.java  |   3 +-
 .../hugegraph/example/ThreadRangePerfTest.java     |   3 +-
 .../src/main/resources/log4j2.xml                  |  20 +-
 .../backend/store/hbase/HbaseMetrics.java          |  10 +-
 .../backend/store/hbase/HbaseOptions.java          |   2 +-
 .../backend/store/hbase/HbaseSerializer.java       |   3 +-
 .../backend/store/hbase/HbaseSessions.java         |  18 +-
 .../hugegraph/backend/store/hbase/HbaseStore.java  |  55 +--
 .../hugegraph/backend/store/hbase/HbaseTable.java  |  16 +-
 .../hugegraph/backend/store/hbase/HbaseTables.java |   3 +-
 .../backend/store/mysql/MysqlEntryIterator.java    |   4 +-
 .../backend/store/mysql/MysqlMetrics.java          |   1 +
 .../backend/store/mysql/MysqlOptions.java          |   6 +-
 .../backend/store/mysql/MysqlSerializer.java       |   3 +-
 .../backend/store/mysql/MysqlSessions.java         |  20 +-
 .../hugegraph/backend/store/mysql/MysqlStore.java  |  13 +-
 .../hugegraph/backend/store/mysql/MysqlTable.java  |  24 +-
 .../hugegraph/backend/store/mysql/MysqlTables.java |  21 +-
 .../backend/store/mysql/WhereBuilder.java          |  34 +-
 .../hugegraph/backend/store/palo/PaloFile.java     |   2 +-
 .../hugegraph/backend/store/palo/PaloSessions.java |   6 +-
 .../hugegraph/backend/store/palo/PaloStore.java    |   3 +-
 .../backend/store/palo/PaloStoreProvider.java      |   4 +-
 .../hugegraph/backend/store/palo/PaloTable.java    |   5 +-
 .../hugegraph/backend/store/palo/PaloTables.java   |  10 +-
 .../store/postgresql/PostgresqlSerializer.java     |   5 +-
 .../store/postgresql/PostgresqlSessions.java       |  34 +-
 .../store/postgresql/PostgresqlStoreProvider.java  |   9 +-
 .../backend/store/postgresql/PostgresqlTable.java  |   6 +-
 .../backend/store/postgresql/PostgresqlTables.java |  34 +-
 .../backend/store/rocksdb/RocksDBStdSessions.java  |  36 +-
 .../backend/store/rocksdb/RocksDBStore.java        |   4 +-
 .../backend/store/rocksdb/RocksDBTable.java        |   2 +-
 .../store/rocksdbsst/RocksDBSstSessions.java       |   4 +-
 .../backend/store/rocksdbsst/RocksDBSstStore.java  |   2 +-
 .../backend/store/scylladb/ScyllaDBMetrics.java    |   1 -
 .../store/scylladb/ScyllaDBStoreProvider.java      |   9 +-
 .../store/scylladb/ScyllaDBTablesWithMV.java       |  51 +--
 hugegraph-server/hugegraph-test/pom.xml            |   2 +-
 .../org/apache/hugegraph/api/ApiTestSuite.java     |  32 +-
 .../java/org/apache/hugegraph/api/BaseApiTest.java | 274 ++++++-------
 .../org/apache/hugegraph/api/CypherApiTest.java    |   2 +-
 .../java/org/apache/hugegraph/api/EdgeApiTest.java | 176 ++++----
 .../org/apache/hugegraph/api/EdgeLabelApiTest.java |  96 ++---
 .../org/apache/hugegraph/api/GremlinApiTest.java   | 193 ++++-----
 .../apache/hugegraph/api/IndexLabelApiTest.java    | 102 ++---
 .../org/apache/hugegraph/api/LoginApiTest.java     |   9 +-
 .../org/apache/hugegraph/api/ProjectApiTest.java   |   6 +-
 .../apache/hugegraph/api/PropertyKeyApiTest.java   |  40 +-
 .../java/org/apache/hugegraph/api/TaskApiTest.java |  10 +-
 .../java/org/apache/hugegraph/api/UserApiTest.java |  10 +-
 .../org/apache/hugegraph/api/VertexApiTest.java    |  48 +--
 .../apache/hugegraph/api/VertexLabelApiTest.java   |  72 ++--
 .../api/traversers/AdamicAdarAPITest.java          |   6 +-
 .../api/traversers/AllShortestPathsApiTest.java    |   2 +-
 .../hugegraph/api/traversers/CountApiTest.java     |   6 +-
 .../api/traversers/CrosspointsApiTest.java         |   9 +-
 .../traversers/CustomizedCrosspointsApiTest.java   |   4 +-
 .../hugegraph/api/traversers/EdgesApiTest.java     |   9 +-
 .../api/traversers/FusiformSimilarityApiTest.java  |   4 +-
 .../traversers/MultiNodeShortestPathApiTest.java   |   4 +-
 .../api/traversers/NeighborRankApiTest.java        |   4 +-
 .../hugegraph/api/traversers/PathsApiTest.java     |   6 +-
 .../api/traversers/PersonalRankApiTest.java        |   4 +-
 .../api/traversers/ResourceAllocationAPITest.java  |   6 +-
 .../hugegraph/api/traversers/RingsApiTest.java     |   5 +-
 .../api/traversers/ShortestPathApiTest.java        |   5 +-
 .../api/traversers/TemplatePathsApiTest.java       |   5 +-
 .../api/traversers/TraversersApiTestSuite.java     |  45 ++-
 .../traversers/WeightedShortestPathApiTest.java    |   5 +-
 .../java/org/apache/hugegraph/core/AuthTest.java   | 100 ++---
 .../org/apache/hugegraph/core/CoreTestSuite.java   |  27 +-
 .../org/apache/hugegraph/core/EdgeCoreTest.java    | 319 +++++++--------
 .../apache/hugegraph/core/EdgeLabelCoreTest.java   |  48 +--
 .../apache/hugegraph/core/IndexLabelCoreTest.java  |  72 ++--
 .../apache/hugegraph/core/PropertyCoreTest.java    |  22 +-
 .../apache/hugegraph/core/PropertyKeyCoreTest.java |  12 +-
 .../org/apache/hugegraph/core/RamTableTest.java    |  31 +-
 .../org/apache/hugegraph/core/RestoreCoreTest.java | 127 +++---
 .../core/RoleElectionStateMachineTest.java         |   2 +-
 .../org/apache/hugegraph/core/SchemaCoreTest.java  |   5 +-
 .../org/apache/hugegraph/core/TaskCoreTest.java    | 157 ++++----
 .../org/apache/hugegraph/core/VertexCoreTest.java  | 390 +++++++++---------
 .../apache/hugegraph/core/VertexLabelCoreTest.java |  40 +-
 .../org/apache/hugegraph/testutil/FakeObjects.java |   3 +-
 .../java/org/apache/hugegraph/testutil/Utils.java  |   7 +-
 .../hugegraph/tinkerpop/ProcessBasicSuite.java     | 286 ++++++-------
 .../hugegraph/tinkerpop/ProcessStandardTest.java   |   1 +
 .../hugegraph/tinkerpop/StructureBasicSuite.java   |  61 +--
 .../hugegraph/tinkerpop/StructureStandardTest.java |   1 +
 .../org/apache/hugegraph/tinkerpop/TestGraph.java  |   5 +-
 .../hugegraph/tinkerpop/TestGraphFactory.java      |   2 +-
 .../hugegraph/tinkerpop/TestGraphProvider.java     |  50 +--
 .../tinkerpop/tests/HugeGraphWriteTest.java        |  11 +-
 .../org/apache/hugegraph/unit/BaseUnitTest.java    |   7 +-
 .../org/apache/hugegraph/unit/FakeObjects.java     |   9 +-
 .../org/apache/hugegraph/unit/UnitTestSuite.java   | 137 +++----
 .../hugegraph/unit/cache/CacheManagerTest.java     |  20 +-
 .../org/apache/hugegraph/unit/cache/CacheTest.java |  16 +-
 .../unit/cache/CachedGraphTransactionTest.java     |   9 +-
 .../unit/cache/CachedSchemaTransactionTest.java    |   8 +-
 .../apache/hugegraph/unit/cache/RamTableTest.java  |   9 +-
 .../hugegraph/unit/cassandra/CassandraTest.java    |  20 +-
 .../apache/hugegraph/unit/core/AnalyzerTest.java   |  11 +-
 .../hugegraph/unit/core/BackendMutationTest.java   |   7 +-
 .../hugegraph/unit/core/BackendStoreInfoTest.java  |   7 +-
 .../unit/core/ConditionQueryFlattenTest.java       |   8 +-
 .../apache/hugegraph/unit/core/ConditionTest.java  |   4 +-
 .../apache/hugegraph/unit/core/DataTypeTest.java   |   5 +-
 .../apache/hugegraph/unit/core/DirectionsTest.java |   5 +-
 .../apache/hugegraph/unit/core/ExceptionTest.java  |   4 +-
 .../apache/hugegraph/unit/core/LocksTableTest.java |  10 +-
 .../apache/hugegraph/unit/core/PageStateTest.java  |   3 +-
 .../org/apache/hugegraph/unit/core/QueryTest.java  |   4 +-
 .../org/apache/hugegraph/unit/core/RangeTest.java  |  11 +-
 .../hugegraph/unit/core/RolePermissionTest.java    |  46 ++-
 .../apache/hugegraph/unit/core/RowLockTest.java    |  11 +-
 .../hugegraph/unit/core/SecurityManagerTest.java   |  14 +-
 .../apache/hugegraph/unit/core/SerialEnumTest.java |   3 +-
 .../hugegraph/unit/core/SystemSchemaStoreTest.java |   5 +-
 .../hugegraph/unit/core/TraversalUtilTest.java     |  19 +-
 .../org/apache/hugegraph/unit/id/EdgeIdTest.java   |  10 +-
 .../java/org/apache/hugegraph/unit/id/IdTest.java  |  12 +-
 .../org/apache/hugegraph/unit/id/IdUtilTest.java   |   5 +-
 .../hugegraph/unit/id/SplicingIdGeneratorTest.java |  16 +-
 .../apache/hugegraph/unit/mysql/MysqlUtilTest.java |   3 +-
 .../hugegraph/unit/mysql/WhereBuilderTest.java     |   4 +-
 .../hugegraph/unit/rocksdb/RocksDBPerfTest.java    |   4 +-
 .../hugegraph/unit/rocksdb/RocksDBSessionTest.java |  23 +-
 .../hugegraph/unit/serializer/BytesBufferTest.java |  10 +-
 .../unit/serializer/SerializerFactoryTest.java     |   5 +-
 .../unit/serializer/StoreSerializerTest.java       |   7 +-
 .../unit/serializer/TableBackendEntryTest.java     |   4 +-
 .../unit/serializer/TextBackendEntryTest.java      |   4 +-
 .../hugegraph/unit/util/CompressUtilTest.java      |   6 +-
 .../apache/hugegraph/unit/util/JsonUtilTest.java   |  33 +-
 .../hugegraph/unit/util/RateLimiterTest.java       |   5 +-
 .../hugegraph/unit/util/StringEncodingTest.java    |  13 +-
 .../apache/hugegraph/unit/util/VersionTest.java    |   5 +-
 .../util/collection/CollectionFactoryTest.java     |  12 +-
 .../hugegraph/unit/util/collection/IdSetTest.java  |   9 +-
 .../unit/util/collection/Int2IntsMapTest.java      |  47 ++-
 .../hugegraph/unit/util/collection/IntMapTest.java |  18 +-
 .../hugegraph/unit/util/collection/IntSetTest.java |  11 +-
 .../unit/util/collection/ObjectIntMappingTest.java |   9 +-
 .../hugegraph-test/src/main/resources/log4j2.xml   |  26 +-
 .../map/MapRandomGetPutThroughputTest.java         |   8 +-
 487 files changed, 5007 insertions(+), 4734 deletions(-)


(incubator-hugegraph) 01/03: fix: format and clean code in dist and example modules (#2441)

Posted by vg...@apache.org.
This is an automated email from the ASF dual-hosted git repository.

vgalaxies pushed a commit to branch pd-store
in repository https://gitbox.apache.org/repos/asf/incubator-hugegraph.git

commit 721111d11a919d9b02577a565c6c15cfe23eebf4
Author: M <87...@users.noreply.github.com>
AuthorDate: Tue Feb 20 17:22:07 2024 +0800

    fix: format and clean code in dist and example modules (#2441)
---
 .../src/assembly/static/conf/gremlin-server.yaml   |  50 ++++----
 .../src/assembly/static/conf/log4j2.xml            |  26 ++--
 .../src/assembly/static/conf/remote-objects.yaml   |   4 +-
 .../assembly/travis/conf-raft1/gremlin-server.yaml |  40 +++---
 .../assembly/travis/conf-raft2/gremlin-server.yaml |  40 +++---
 .../assembly/travis/conf-raft3/gremlin-server.yaml |  40 +++---
 .../hugegraph-dist/src/assembly/travis/maven.xml   |  40 +++---
 .../java/org/apache/hugegraph/cmd/ConfDumper.java  |   7 +-
 .../java/org/apache/hugegraph/cmd/InitStore.java   |   5 +-
 .../org/apache/hugegraph/dist/HugeGraphServer.java |   2 +-
 .../apache/hugegraph/dist/HugeGremlinServer.java   |   7 +-
 .../org/apache/hugegraph/dist/HugeRestServer.java  |   3 +-
 .../org/apache/hugegraph/dist/RegisterUtil.java    |  37 ++++--
 .../hugegraph-dist/src/main/resources/log4j2.xml   |  26 ++--
 .../org/apache/hugegraph/example/Example1.java     |  29 +++--
 .../org/apache/hugegraph/example/Example2.java     |  43 ++++---
 .../org/apache/hugegraph/example/Example3.java     |   7 +-
 .../org/apache/hugegraph/example/ExampleUtil.java  |   5 +-
 .../hugegraph/example/GraphOfTheMoviesExample.java | 134 ++++++++++-----------
 .../org/apache/hugegraph/example/PerfExample1.java |   6 +-
 .../org/apache/hugegraph/example/PerfExample2.java |   6 +-
 .../org/apache/hugegraph/example/PerfExample3.java |   7 +-
 .../org/apache/hugegraph/example/PerfExample4.java |   6 +-
 .../apache/hugegraph/example/PerfExampleBase.java  |   7 +-
 .../org/apache/hugegraph/example/TaskExample.java  |   3 +-
 .../hugegraph/example/ThreadRangePerfTest.java     |   3 +-
 .../src/main/resources/log4j2.xml                  |  20 +--
 27 files changed, 304 insertions(+), 299 deletions(-)

diff --git a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/gremlin-server.yaml b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/gremlin-server.yaml
index 594677982..32135163f 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/gremlin-server.yaml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/gremlin-server.yaml
@@ -28,8 +28,8 @@ graphs: {
 scriptEngines: {
   gremlin-groovy: {
     staticImports: [
-        org.opencypher.gremlin.process.traversal.CustomPredicates.*',
-        org.opencypher.gremlin.traversal.CustomFunctions.*
+      org.opencypher.gremlin.process.traversal.CustomPredicates.*',
+      org.opencypher.gremlin.traversal.CustomFunctions.*
     ],
     plugins: {
       org.apache.hugegraph.plugin.HugeGraphGremlinPlugin: {},
@@ -70,9 +70,9 @@ scriptEngines: {
           org.opencypher.gremlin.traversal.CustomPredicate
         ],
         methodImports: [
-            java.lang.Math#*,
-            org.opencypher.gremlin.traversal.CustomPredicate#*,
-            org.opencypher.gremlin.traversal.CustomFunctions#*
+          java.lang.Math#*,
+          org.opencypher.gremlin.traversal.CustomPredicate#*,
+          org.opencypher.gremlin.traversal.CustomFunctions#*
         ]
       },
       org.apache.tinkerpop.gremlin.jsr223.ScriptFileGremlinPlugin: {
@@ -82,29 +82,29 @@ scriptEngines: {
   }
 }
 serializers:
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
 metrics: {
   consoleReporter: {enabled: false, interval: 180000},
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/log4j2.xml b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/log4j2.xml
index 0248da07d..f1dd7e839 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/log4j2.xml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/log4j2.xml
@@ -30,14 +30,14 @@
 
         <!-- Normal server log config -->
         <RollingRandomAccessFile name="file" fileName="${LOG_PATH}/${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
-            immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
+                                 immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} [%t] [%p] %c{1.} - %m%n"/>
             <!-- Trigger after exceeding 1day or 50MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="50MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 5 files per day & auto delete after over 2GB or 100 files -->
             <DefaultRolloverStrategy max="5">
@@ -45,8 +45,8 @@
                     <IfFileName glob="*/*.log"/>
                     <!-- Limit log amount & size -->
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="2GB" />
-                        <IfAccumulatedFileCount exceeds="100" />
+                        <IfAccumulatedFileSize exceeds="2GB"/>
+                        <IfAccumulatedFileCount exceeds="100"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
@@ -54,15 +54,15 @@
 
         <!-- Separate & compress audit log, buffer size is 512KB -->
         <RollingRandomAccessFile name="audit" fileName="${LOG_PATH}/audit-${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
-            bufferSize="524288" immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
+                                 bufferSize="524288" immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <!-- Use simple format for audit log to speed up -->
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} - %m%n"/>
             <!-- Trigger after exceeding 1hour or 500MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="500MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 2 files per hour & auto delete [after 60 days] or [over 5GB or 500 files] -->
             <DefaultRolloverStrategy max="2">
@@ -70,8 +70,8 @@
                     <IfFileName glob="*/*.gz"/>
                     <IfLastModified age="60d"/>
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="5GB" />
-                        <IfAccumulatedFileCount exceeds="500" />
+                        <IfAccumulatedFileSize exceeds="5GB"/>
+                        <IfAccumulatedFileCount exceeds="500"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
@@ -86,7 +86,7 @@
             <!-- Trigger after exceeding 1day or 50MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="50MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 5 files per day & auto delete after over 2GB or 100 files -->
             <DefaultRolloverStrategy max="5">
@@ -94,8 +94,8 @@
                     <IfFileName glob="*/*.log"/>
                     <!-- Limit log amount & size -->
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="2GB" />
-                        <IfAccumulatedFileCount exceeds="100" />
+                        <IfAccumulatedFileSize exceeds="2GB"/>
+                        <IfAccumulatedFileCount exceeds="100"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/remote-objects.yaml b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/remote-objects.yaml
index 8ba24d00a..39679d8c3 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/static/conf/remote-objects.yaml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/static/conf/remote-objects.yaml
@@ -23,8 +23,8 @@ serializer: {
     # The duplication of HugeGraphIoRegistry is meant to fix a bug in the
     # 'org.apache.tinkerpop.gremlin.driver.Settings:from(Configuration)' method.
     ioRegistries: [
-        org.apache.hugegraph.io.HugeGraphIoRegistry,
-        org.apache.hugegraph.io.HugeGraphIoRegistry
+      org.apache.hugegraph.io.HugeGraphIoRegistry,
+      org.apache.hugegraph.io.HugeGraphIoRegistry
     ]
   }
 }
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft1/gremlin-server.yaml b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft1/gremlin-server.yaml
index 55a8c0bb3..7e10eb52b 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft1/gremlin-server.yaml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft1/gremlin-server.yaml
@@ -74,29 +74,29 @@ scriptEngines: {
   }
 }
 serializers:
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
 metrics: {
   consoleReporter: {enabled: false, interval: 180000},
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft2/gremlin-server.yaml b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft2/gremlin-server.yaml
index 54d9a6dde..5f097f91b 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft2/gremlin-server.yaml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft2/gremlin-server.yaml
@@ -74,29 +74,29 @@ scriptEngines: {
   }
 }
 serializers:
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
 metrics: {
   consoleReporter: {enabled: false, interval: 180000},
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft3/gremlin-server.yaml b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft3/gremlin-server.yaml
index 508abef35..3f50c6477 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft3/gremlin-server.yaml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/travis/conf-raft3/gremlin-server.yaml
@@ -74,29 +74,29 @@ scriptEngines: {
   }
 }
 serializers:
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
-  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
-      config: {
-        serializeResultToString: false,
-        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
-      }
+  - {className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
+     config: {
+       serializeResultToString: false,
+       ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
+     }
   }
 metrics: {
   consoleReporter: {enabled: false, interval: 180000},
diff --git a/hugegraph-server/hugegraph-dist/src/assembly/travis/maven.xml b/hugegraph-server/hugegraph-dist/src/assembly/travis/maven.xml
index 550716769..ef01a3f20 100644
--- a/hugegraph-server/hugegraph-dist/src/assembly/travis/maven.xml
+++ b/hugegraph-server/hugegraph-dist/src/assembly/travis/maven.xml
@@ -15,24 +15,24 @@
   limitations under the License.
   -->
 <settings>
-  <servers>
-    <server>
-      <id>ossrh</id>
-      <username>${env.MAVEN_REPO_USERNAME}</username>
-      <password>${env.MAVEN_REPO_PASSWORD}</password>
-    </server>
-  </servers>
-  <profiles>
-    <profile>
-      <id>release</id>
-      <activation>
-        <activeByDefault>false</activeByDefault>
-      </activation>
-      <properties>
-        <gpg.executable>gpg</gpg.executable>
-        <gpg.keyname>${env.GPG_KEY_ID}</gpg.keyname>
-        <gpg.passphrase>${env.GPG_PASSPHRASE}</gpg.passphrase>
-      </properties>
-    </profile>
-  </profiles>
+    <servers>
+        <server>
+            <id>ossrh</id>
+            <username>${env.MAVEN_REPO_USERNAME}</username>
+            <password>${env.MAVEN_REPO_PASSWORD}</password>
+        </server>
+    </servers>
+    <profiles>
+        <profile>
+            <id>release</id>
+            <activation>
+                <activeByDefault>false</activeByDefault>
+            </activation>
+            <properties>
+                <gpg.executable>gpg</gpg.executable>
+                <gpg.keyname>${env.GPG_KEY_ID}</gpg.keyname>
+                <gpg.passphrase>${env.GPG_PASSPHRASE}</gpg.passphrase>
+            </properties>
+        </profile>
+    </profiles>
 </settings>
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/ConfDumper.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/ConfDumper.java
index cdeb32140..6bbb24e26 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/ConfDumper.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/ConfDumper.java
@@ -23,14 +23,13 @@ import java.util.TreeSet;
 
 import org.apache.commons.configuration.ConfigurationException;
 import org.apache.commons.io.FileUtils;
-import org.apache.hugegraph.dist.RegisterUtil;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.config.OptionSpace;
 import org.apache.hugegraph.config.TypedOption;
+import org.apache.hugegraph.dist.RegisterUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class ConfDumper {
 
@@ -39,7 +38,7 @@ public class ConfDumper {
     private static final Logger LOG = Log.logger(ConfDumper.class);
 
     public static void main(String[] args)
-                       throws ConfigurationException, IOException {
+            throws ConfigurationException, IOException {
         E.checkArgument(args.length == 1,
                         "ConfDumper need a config file.");
 
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/InitStore.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/InitStore.java
index 75199d1e7..e226e381f 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/InitStore.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/cmd/InitStore.java
@@ -117,9 +117,10 @@ public class InitStore {
     }
 
     private static void initBackend(final HugeGraph graph)
-                                    throws InterruptedException {
+            throws InterruptedException {
         int retries = RETRIES;
-        retry: do {
+        retry:
+        do {
             try {
                 graph.initBackend();
             } catch (Exception e) {
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGraphServer.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGraphServer.java
index 7af1ff8b0..ae2c73e2c 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGraphServer.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGraphServer.java
@@ -45,7 +45,7 @@ public class HugeGraphServer {
     }
 
     public HugeGraphServer(String gremlinServerConf, String restServerConf)
-                           throws Exception {
+            throws Exception {
         // Only switch on security manager after HugeGremlinServer started
         SecurityManager securityManager = System.getSecurityManager();
         System.setSecurityManager(null);
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGremlinServer.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGremlinServer.java
index 7d7a992a5..edc4391ef 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGremlinServer.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeGremlinServer.java
@@ -17,16 +17,15 @@
 
 package org.apache.hugegraph.dist;
 
-import org.apache.tinkerpop.gremlin.server.GremlinServer;
-import org.apache.tinkerpop.gremlin.server.Settings;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.auth.ContextGremlinServer;
 import org.apache.hugegraph.event.EventHub;
 import org.apache.hugegraph.util.ConfigUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.server.GremlinServer;
+import org.apache.tinkerpop.gremlin.server.Settings;
+import org.slf4j.Logger;
 
 public class HugeGremlinServer {
 
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeRestServer.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeRestServer.java
index 395ae886d..6edb818be 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeRestServer.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/HugeRestServer.java
@@ -17,11 +17,10 @@
 
 package org.apache.hugegraph.dist;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.event.EventHub;
 import org.apache.hugegraph.server.RestServer;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class HugeRestServer {
 
diff --git a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/RegisterUtil.java b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/RegisterUtil.java
index a6570986a..69d6674d0 100644
--- a/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/RegisterUtil.java
+++ b/hugegraph-server/hugegraph-dist/src/main/java/org/apache/hugegraph/dist/RegisterUtil.java
@@ -105,10 +105,12 @@ public class RegisterUtil {
                              "org.apache.hugegraph.backend.store.cassandra.CassandraOptions");
         // Register serializer
         SerializerFactory.register("cassandra",
-                "org.apache.hugegraph.backend.store.cassandra.CassandraSerializer");
+                                   "org.apache.hugegraph.backend.store.cassandra" +
+                                   ".CassandraSerializer");
         // Register backend
         BackendProviderFactory.register("cassandra",
-                "org.apache.hugegraph.backend.store.cassandra.CassandraStoreProvider");
+                                        "org.apache.hugegraph.backend.store.cassandra" +
+                                        ".CassandraStoreProvider");
     }
 
     public static void registerScyllaDB() {
@@ -117,10 +119,12 @@ public class RegisterUtil {
                              "org.apache.hugegraph.backend.store.cassandra.CassandraOptions");
         // Register serializer
         SerializerFactory.register("scylladb",
-                "org.apache.hugegraph.backend.store.cassandra.CassandraSerializer");
+                                   "org.apache.hugegraph.backend.store.cassandra" +
+                                   ".CassandraSerializer");
         // Register backend
         BackendProviderFactory.register("scylladb",
-                "org.apache.hugegraph.backend.store.scylladb.ScyllaDBStoreProvider");
+                                        "org.apache.hugegraph.backend.store.scylladb" +
+                                        ".ScyllaDBStoreProvider");
     }
 
     public static void registerHBase() {
@@ -132,7 +136,8 @@ public class RegisterUtil {
                                    "org.apache.hugegraph.backend.store.hbase.HbaseSerializer");
         // Register backend
         BackendProviderFactory.register("hbase",
-                "org.apache.hugegraph.backend.store.hbase.HbaseStoreProvider");
+                                        "org.apache.hugegraph.backend.store.hbase" +
+                                        ".HbaseStoreProvider");
     }
 
     public static void registerRocksDB() {
@@ -141,9 +146,11 @@ public class RegisterUtil {
                              "org.apache.hugegraph.backend.store.rocksdb.RocksDBOptions");
         // Register backend
         BackendProviderFactory.register("rocksdb",
-                "org.apache.hugegraph.backend.store.rocksdb.RocksDBStoreProvider");
+                                        "org.apache.hugegraph.backend.store.rocksdb" +
+                                        ".RocksDBStoreProvider");
         BackendProviderFactory.register("rocksdbsst",
-                "org.apache.hugegraph.backend.store.rocksdbsst.RocksDBSstStoreProvider");
+                                        "org.apache.hugegraph.backend.store.rocksdbsst" +
+                                        ".RocksDBSstStoreProvider");
     }
 
     public static void registerMysql() {
@@ -155,7 +162,8 @@ public class RegisterUtil {
                                    "org.apache.hugegraph.backend.store.mysql.MysqlSerializer");
         // Register backend
         BackendProviderFactory.register("mysql",
-                "org.apache.hugegraph.backend.store.mysql.MysqlStoreProvider");
+                                        "org.apache.hugegraph.backend.store.mysql" +
+                                        ".MysqlStoreProvider");
     }
 
     public static void registerPalo() {
@@ -164,22 +172,25 @@ public class RegisterUtil {
                              "org.apache.hugegraph.backend.store.palo.PaloOptions");
         // Register serializer
         SerializerFactory.register("palo",
-                "org.apache.hugegraph.backend.store.palo.PaloSerializer");
+                                   "org.apache.hugegraph.backend.store.palo.PaloSerializer");
         // Register backend
         BackendProviderFactory.register("palo",
-                "org.apache.hugegraph.backend.store.palo.PaloStoreProvider");
+                                        "org.apache.hugegraph.backend.store.palo" +
+                                        ".PaloStoreProvider");
     }
 
     public static void registerPostgresql() {
         // Register config
         OptionSpace.register("postgresql",
-                "org.apache.hugegraph.backend.store.postgresql.PostgresqlOptions");
+                             "org.apache.hugegraph.backend.store.postgresql.PostgresqlOptions");
         // Register serializer
         SerializerFactory.register("postgresql",
-                "org.apache.hugegraph.backend.store.postgresql.PostgresqlSerializer");
+                                   "org.apache.hugegraph.backend.store.postgresql" +
+                                   ".PostgresqlSerializer");
         // Register backend
         BackendProviderFactory.register("postgresql",
-                "org.apache.hugegraph.backend.store.postgresql.PostgresqlStoreProvider");
+                                        "org.apache.hugegraph.backend.store.postgresql" +
+                                        ".PostgresqlStoreProvider");
     }
 
     public static void registerServer() {
diff --git a/hugegraph-server/hugegraph-dist/src/main/resources/log4j2.xml b/hugegraph-server/hugegraph-dist/src/main/resources/log4j2.xml
index 72bee2a80..b249fdae4 100644
--- a/hugegraph-server/hugegraph-dist/src/main/resources/log4j2.xml
+++ b/hugegraph-server/hugegraph-dist/src/main/resources/log4j2.xml
@@ -30,14 +30,14 @@
 
         <!-- Normal server log config -->
         <RollingRandomAccessFile name="file" fileName="${LOG_PATH}/${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
-            immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
+                                 immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} [%t] [%p] %c{1.} - %m%n"/>
             <!-- Trigger after exceeding 1day or 50MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="50MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 5 files per day & auto delete after over 2GB or 100 files -->
             <DefaultRolloverStrategy max="5">
@@ -45,8 +45,8 @@
                     <IfFileName glob="*/*.log"/>
                     <!-- Limit log amount & size -->
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="2GB" />
-                        <IfAccumulatedFileCount exceeds="100" />
+                        <IfAccumulatedFileSize exceeds="2GB"/>
+                        <IfAccumulatedFileCount exceeds="100"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
@@ -54,15 +54,15 @@
 
         <!-- Separate & compress audit log, buffer size is 512KB -->
         <RollingRandomAccessFile name="audit" fileName="${LOG_PATH}/audit-${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
-            bufferSize="524288" immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
+                                 bufferSize="524288" immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <!-- Use simple format for audit log to speed up -->
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} - %m%n"/>
             <!-- Trigger after exceeding 1hour or 500MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="500MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 2 files per hour & auto delete [after 60 days] or [over 5GB or 500 files] -->
             <DefaultRolloverStrategy max="2">
@@ -70,8 +70,8 @@
                     <IfFileName glob="*/*.gz"/>
                     <IfLastModified age="60d"/>
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="5GB" />
-                        <IfAccumulatedFileCount exceeds="500" />
+                        <IfAccumulatedFileSize exceeds="5GB"/>
+                        <IfAccumulatedFileCount exceeds="500"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
@@ -86,7 +86,7 @@
             <!-- Trigger after exceeding 1day or 50MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="50MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 5 files per day & auto delete after over 2GB or 100 files -->
             <DefaultRolloverStrategy max="5">
@@ -94,8 +94,8 @@
                     <IfFileName glob="*/*.log"/>
                     <!-- Limit log amount & size -->
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="2GB" />
-                        <IfAccumulatedFileCount exceeds="100" />
+                        <IfAccumulatedFileSize exceeds="2GB"/>
+                        <IfAccumulatedFileCount exceeds="100"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example1.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example1.java
index f0e751547..b9ca383bd 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example1.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example1.java
@@ -21,14 +21,6 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 
-import org.apache.tinkerpop.gremlin.process.traversal.P;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Graph;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.BackendException;
@@ -45,6 +37,13 @@ import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.process.traversal.P;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
 
 public class Example1 {
 
@@ -79,9 +78,9 @@ public class Example1 {
             graph.tx().commit();
 
             // New tx
-            GraphTransaction tx =  Whitebox.invoke(graph.getClass(),
-                                                   "openGraphTransaction",
-                                                   graph);
+            GraphTransaction tx = Whitebox.invoke(graph.getClass(),
+                                                  "openGraphTransaction",
+                                                  graph);
 
             tx.addVertex(T.label, "book", "name", "java-21");
             tx.addVertex(T.label, "book", "name", "java-22");
@@ -214,13 +213,13 @@ public class Example1 {
         graph.tx().commit();
 
         // must commit manually with new backend tx (independent of tinkerpop)
-        GraphTransaction tx =  Whitebox.invoke(graph.getClass(),
-                                               "openGraphTransaction",
-                                               graph);
+        GraphTransaction tx = Whitebox.invoke(graph.getClass(),
+                                              "openGraphTransaction",
+                                              graph);
 
         LOG.info("===============  addVertex  ================");
         Vertex james = tx.addVertex(T.label, "author", "id", 1,
-                                    "name", "James Gosling",  "age", 62,
+                                    "name", "James Gosling", "age", 62,
                                     "lived", "San Francisco Bay Area");
 
         Vertex java = tx.addVertex(T.label, "language", "name", "java",
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example2.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example2.java
index db63e37f4..2933279d1 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example2.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example2.java
@@ -19,6 +19,10 @@ package org.apache.hugegraph.example;
 
 import java.util.List;
 
+import org.apache.hugegraph.HugeFactory;
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.hugegraph.util.Log;
 import org.apache.tinkerpop.gremlin.process.traversal.P;
 import org.apache.tinkerpop.gremlin.process.traversal.Path;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
@@ -29,11 +33,6 @@ import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.HugeFactory;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.schema.SchemaManager;
-import org.apache.hugegraph.util.Log;
-
 public class Example2 {
 
     private static final Logger LOG = Log.logger(Example2.class);
@@ -93,7 +92,7 @@ public class Example2 {
 
         String person = graph.schema().getVertexLabel("person").id().asString();
         String software = graph.schema().getVertexLabel("software").id()
-                          .asString();
+                               .asString();
         String markoId = String.format("%s:%s", person, "marko");
         String joshId = String.format("%s:%s", person, "josh");
         String lopId = String.format("%s:%s", software, "lop");
@@ -122,30 +121,30 @@ public class Example2 {
         assert paths.get(0).get(1).equals("lop");
 
         LOG.info(">>>> query with out() optimize: {}",
-                graph.traversal().V(markoId)
-                .out()
-                .out()
-                .values("name").toList());
+                 graph.traversal().V(markoId)
+                      .out()
+                      .out()
+                      .values("name").toList());
 
         LOG.info(">>>> query with out() optimize and path(): {}",
-                graph.traversal().V()
-                .out("knows")
-                .out("created")
-                .values("name")
-                .path()
-                .toList());
+                 graph.traversal().V()
+                      .out("knows")
+                      .out("created")
+                      .values("name")
+                      .path()
+                      .toList());
     }
 
     public static List<Path> shortestPath(final HugeGraph graph,
                                           Object from, Object to,
                                           int maxDepth) {
         GraphTraversal<Vertex, Path> t = graph.traversal()
-                .V(from)
-                .repeat(__.out().simplePath())
-                .until(__.hasId(to).or().loops().is(P.gt(maxDepth)))
-                .hasId(to)
-                .path().by("name")
-                .limit(1);
+                                              .V(from)
+                                              .repeat(__.out().simplePath())
+                                              .until(__.hasId(to).or().loops().is(P.gt(maxDepth)))
+                                              .hasId(to)
+                                              .path().by("name")
+                                              .limit(1);
         return t.toList();
     }
 
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example3.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example3.java
index 6dd877c35..5e1f57d5a 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example3.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/Example3.java
@@ -17,14 +17,13 @@
 
 package org.apache.hugegraph.example;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
 
 public class Example3 {
 
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ExampleUtil.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ExampleUtil.java
index 06f7517bb..e81d5e403 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ExampleUtil.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ExampleUtil.java
@@ -33,6 +33,7 @@ import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 public class ExampleUtil {
+
     private static final Logger LOG = Log.logger(ExampleUtil.class);
 
     private static boolean registered = false;
@@ -65,13 +66,13 @@ public class ExampleUtil {
         String conf = "hugegraph.properties";
         try {
             String path = ExampleUtil.class.getClassLoader()
-                                     .getResource(conf).getPath();
+                                           .getResource(conf).getPath();
             File file = new File(path);
             if (file.exists() && file.isFile()) {
                 conf = path;
             }
         } catch (Exception ignored) {
-            LOG.warn("loadGraph warn {} ",ignored);
+            LOG.warn("loadGraph warn {} ", ignored);
         }
 
         HugeGraph graph = HugeFactory.open(conf);
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/GraphOfTheMoviesExample.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/GraphOfTheMoviesExample.java
index 3ac67b5af..60ef236f9 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/GraphOfTheMoviesExample.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/GraphOfTheMoviesExample.java
@@ -19,17 +19,16 @@ package org.apache.hugegraph.example;
 
 import java.util.List;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.perf.PerfUtil;
+import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.hugegraph.util.Log;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.perf.PerfUtil;
-import org.apache.hugegraph.schema.SchemaManager;
-import org.apache.hugegraph.util.Log;
-
 public class GraphOfTheMoviesExample {
 
     private static final Logger LOG = Log.logger(GraphOfTheMoviesExample.class);
@@ -43,7 +42,7 @@ public class GraphOfTheMoviesExample {
         GraphOfTheMoviesExample.load(graph);
         long endTime = System.currentTimeMillis();
         LOG.info(">>>> adding all vertices cost time(s): {}",
-                           (endTime - startTime) / 1000.0);
+                 (endTime - startTime) / 1000.0);
 
         GraphOfTheMoviesExample.query(graph);
 
@@ -107,12 +106,12 @@ public class GraphOfTheMoviesExample {
               .range().create();
 
         Vertex theMatrix = graph.addVertex(T.label, "movie", "title",
-            "The Matrix", "released", 1999);
+                                           "The Matrix", "released", 1999);
         Vertex keanu = graph.addVertex(T.label, "person", "name", "keanu Reeves", "born", 1964);
-        Vertex carrie = graph.addVertex(T.label, "person", "name", 
-            "carrie-anne Moss", "born", 1967);
-        Vertex laurence = graph.addVertex(T.label, "person", "name", 
-            "laurence Fishburne", "born", 1961);
+        Vertex carrie = graph.addVertex(T.label, "person", "name",
+                                        "carrie-anne Moss", "born", 1967);
+        Vertex laurence = graph.addVertex(T.label, "person", "name",
+                                          "laurence Fishburne", "born", 1961);
         Vertex hugo = graph.addVertex(T.label, "person", "name", "hugo Weaving", "born", 1960);
         Vertex lillyW = graph.addVertex(T.label, "person", "name", "Lilly Wachowski", "born", 1967);
         Vertex lanaW = graph.addVertex(T.label, "person", "name", "Lana Wachowski", "born", 1965);
@@ -130,7 +129,7 @@ public class GraphOfTheMoviesExample {
         emil.addEdge("ACTED_IN", theMatrix, "roles", "emil");
 
         Vertex theMatrixReloaded = graph.addVertex(T.label, "movie", "title",
-            "The Matrix Reloaded", "released", 2003);
+                                                   "The Matrix Reloaded", "released", 2003);
 
         keanu.addEdge("ACTED_IN", theMatrixReloaded, "roles", "Neo");
         carrie.addEdge("ACTED_IN", theMatrixReloaded, "roles", "Trinity");
@@ -141,7 +140,7 @@ public class GraphOfTheMoviesExample {
         joelS.addEdge("PRODUCED", theMatrixReloaded, "score", 10);
 
         Vertex theMatrixRevolutions = graph.addVertex(T.label, "movie", "title",
-            "The Matrix Revolutions", "released", 2003);
+                                                      "The Matrix Revolutions", "released", 2003);
 
         keanu.addEdge("ACTED_IN", theMatrixRevolutions, "roles", "Neo");
         carrie.addEdge("ACTED_IN", theMatrixRevolutions, "roles", "Trinity");
@@ -152,10 +151,10 @@ public class GraphOfTheMoviesExample {
         joelS.addEdge("PRODUCED", theMatrixRevolutions, "score", 10);
 
         Vertex theDevilsadvocate = graph.addVertex(T.label, "movie", "title",
-            "The Devil's advocate", "released", 1997);
+                                                   "The Devil's advocate", "released", 1997);
 
         Vertex charlize = graph.addVertex(T.label, "person", "name",
-            "charlize Theron", "born", 1975);
+                                          "charlize Theron", "born", 1975);
         Vertex al = graph.addVertex(T.label, "person", "name", "al Pacino", "born", 1940);
         Vertex taylor = graph.addVertex(T.label, "person", "name", "taylor Hackford", "born", 1944);
 
@@ -165,21 +164,21 @@ public class GraphOfTheMoviesExample {
         taylor.addEdge("DIRECTED", theDevilsadvocate, "score", 10);
 
         Vertex aFewGoodMen = graph.addVertex(T.label, "movie", "title",
-             "a Few Good Men", "released", 1992);
+                                             "a Few Good Men", "released", 1992);
 
         Vertex tomC = graph.addVertex(T.label, "person", "name", "Tom Cruise", "born", 1962);
         Vertex jackN = graph.addVertex(T.label, "person", "name", "Jack Nicholson", "born", 1937);
         Vertex demiM = graph.addVertex(T.label, "person", "name", "Demi Moore", "born", 1962);
         Vertex kevinB = graph.addVertex(T.label, "person", "name", "Kevin Bacon", "born", 1958);
         Vertex kieferS = graph.addVertex(T.label, "person", "name",
-            "Kiefer Sutherland", "born", 1966);
+                                         "Kiefer Sutherland", "born", 1966);
         Vertex noahW = graph.addVertex(T.label, "person", "name", "Noah Wyle", "born", 1971);
         Vertex cubaG = graph.addVertex(T.label, "person", "name", "Cuba Gooding Jr.", "born", 1968);
         Vertex kevinP = graph.addVertex(T.label, "person", "name", "Kevin Pollak", "born", 1957);
         Vertex jtw = graph.addVertex(T.label, "person", "name", "J.T. Walsh", "born", 1943);
         Vertex jamesM = graph.addVertex(T.label, "person", "name", "James Marshall", "born", 1967);
         Vertex christopherG = graph.addVertex(T.label, "person", "name",
-             "Christopher Guest", "born", 1948);
+                                              "Christopher Guest", "born", 1948);
         Vertex robR = graph.addVertex(T.label, "person", "name", "Rob Reiner", "born", 1947);
         Vertex aaronS = graph.addVertex(T.label, "person", "name", "aaron Sorkin", "born", 1961);
 
@@ -203,7 +202,7 @@ public class GraphOfTheMoviesExample {
         Vertex kellyM = graph.addVertex(T.label, "person", "name", "Kelly McGillis", "born", 1957);
         Vertex valK = graph.addVertex(T.label, "person", "name", "Val Kilmer", "born", 1959);
         Vertex anthonyE = graph.addVertex(T.label, "person", "name",
-            "anthony Edwards", "born", 1962);
+                                          "anthony Edwards", "born", 1962);
         Vertex tomS = graph.addVertex(T.label, "person", "name", "Tom Skerritt", "born", 1933);
         Vertex megR = graph.addVertex(T.label, "person", "name", "Meg Ryan", "born", 1961);
         Vertex tonyS = graph.addVertex(T.label, "person", "name", "Tony Scott", "born", 1944);
@@ -219,7 +218,7 @@ public class GraphOfTheMoviesExample {
         jimC.addEdge("WROTE", topGun, "score", 10);
 
         Vertex jerryMaguire = graph.addVertex(T.label, "movie", "title",
-            "Jerry Maguire", "released", 2000);
+                                              "Jerry Maguire", "released", 2000);
 
         Vertex reneeZ = graph.addVertex(T.label, "person", "name", "Renee Zellweger", "born", 1969);
         Vertex kellyP = graph.addVertex(T.label, "person", "name", "Kelly Preston", "born", 1962);
@@ -228,7 +227,7 @@ public class GraphOfTheMoviesExample {
         Vertex bonnieH = graph.addVertex(T.label, "person", "name", "Bonnie Hunt", "born", 1970);
         Vertex reginaK = graph.addVertex(T.label, "person", "name", "Regina King", "born", 1961);
         Vertex jonathanL = graph.addVertex(T.label, "person", "name",
-            "Jonathan Lipnicki", "born", 1996);
+                                           "Jonathan Lipnicki", "born", 1996);
         Vertex cameronC = graph.addVertex(T.label, "person", "name", "Cameron Crowe", "born", 1957);
 
         tomC.addEdge("ACTED_IN", jerryMaguire, "roles", "Jerry Maguire");
@@ -245,14 +244,14 @@ public class GraphOfTheMoviesExample {
         cameronC.addEdge("WROTE", jerryMaguire, "score", 10);
 
         Vertex standByMe = graph.addVertex(T.label, "movie", "title",
-            "Stand By Me", "released", 1986);
+                                           "Stand By Me", "released", 1986);
 
         Vertex riverP = graph.addVertex(T.label, "person", "name", "River Phoenix", "born", 1970);
         Vertex coreyF = graph.addVertex(T.label, "person", "name", "Corey Feldman", "born", 1971);
         Vertex wilW = graph.addVertex(T.label, "person", "name", "Wil Wheaton", "born", 1972);
         Vertex johnC = graph.addVertex(T.label, "person", "name", "John Cusack", "born", 1966);
         Vertex marshallB = graph.addVertex(T.label, "person", "name",
-             "Marshall Bell", "born", 1942);
+                                           "Marshall Bell", "born", 1942);
 
         wilW.addEdge("ACTED_IN", standByMe, "roles", "Gordie Lachance");
         riverP.addEdge("ACTED_IN", standByMe, "roles", "Chris Chambers");
@@ -264,7 +263,7 @@ public class GraphOfTheMoviesExample {
         robR.addEdge("DIRECTED", standByMe, "score", 10);
 
         Vertex asGoodasItGets = graph.addVertex(T.label, "movie", "title",
-             "as Good as It Gets", "released", 1997);
+                                                "as Good as It Gets", "released", 1997);
 
         Vertex helenH = graph.addVertex(T.label, "person", "name", "Helen Hunt", "born", 1963);
         Vertex gregK = graph.addVertex(T.label, "person", "name", "Greg Kinnear", "born", 1963);
@@ -277,10 +276,10 @@ public class GraphOfTheMoviesExample {
         jamesB.addEdge("DIRECTED", asGoodasItGets, "score", 10);
 
         Vertex whatDreamsMayCome = graph.addVertex(T.label, "movie", "title",
-             "What Dreams May Come", "released", 1998);
+                                                   "What Dreams May Come", "released", 1998);
 
         Vertex annabellaS = graph.addVertex(T.label, "person", "name",
-             "annabella Sciorra", "born", 1960);
+                                            "annabella Sciorra", "born", 1960);
         Vertex maxS = graph.addVertex(T.label, "person", "name", "Max von Sydow", "born", 1929);
         Vertex wernerH = graph.addVertex(T.label, "person", "name", "Werner Herzog", "born", 1942);
         Vertex robin = graph.addVertex(T.label, "person", "name", "robin Williams", "born", 1951);
@@ -294,7 +293,7 @@ public class GraphOfTheMoviesExample {
         vincentW.addEdge("DIRECTED", whatDreamsMayCome, "score", 10);
 
         Vertex snowFallingonCedars = graph.addVertex(T.label, "movie", "title",
-             "Snow Falling on Cedars", "released", 1999);
+                                                     "Snow Falling on Cedars", "released", 1999);
 
         Vertex ethanH = graph.addVertex(T.label, "person", "name", "Ethan Hawke", "born", 1970);
         Vertex rickY = graph.addVertex(T.label, "person", "name", "Rick Yune", "born", 1971);
@@ -308,7 +307,7 @@ public class GraphOfTheMoviesExample {
         scottH.addEdge("DIRECTED", snowFallingonCedars, "score", 10);
 
         Vertex youveGotMail = graph.addVertex(T.label, "movie", "title",
-             "You've Got Mail", "released", 1998);
+                                              "You've Got Mail", "released", 1998);
 
         Vertex parkerP = graph.addVertex(T.label, "person", "name", "Parker Posey", "born", 1968);
         Vertex daveC = graph.addVertex(T.label, "person", "name", "Dave Chappelle", "born", 1973);
@@ -325,7 +324,7 @@ public class GraphOfTheMoviesExample {
         noraE.addEdge("DIRECTED", youveGotMail, "score", 10);
 
         Vertex sleeplessInSeattle = graph.addVertex(T.label, "movie", "title",
-             "Sleepless in Seattle", "released", 1993);
+                                                    "Sleepless in Seattle", "released", 1993);
 
         Vertex ritaW = graph.addVertex(T.label, "person", "name", "Rita Wilson", "born", 1956);
         Vertex billPull = graph.addVertex(T.label, "person", "name", "Bill Pullman", "born", 1953);
@@ -341,20 +340,20 @@ public class GraphOfTheMoviesExample {
         noraE.addEdge("DIRECTED", sleeplessInSeattle, "score", 10);
 
         Vertex joeVersustheVolcano = graph.addVertex(T.label, "movie", "title",
-             "Joe Versus the Volcano", "released", 1990);
+                                                     "Joe Versus the Volcano", "released", 1990);
 
         Vertex johnS = graph.addVertex(T.label, "person", "name",
-             "John Patrick Stanley", "born", 1950);
+                                       "John Patrick Stanley", "born", 1950);
         Vertex nathan = graph.addVertex(T.label, "person", "name", "nathan Lane", "born", 1956);
 
         tomH.addEdge("ACTED_IN", joeVersustheVolcano, "roles", "Joe Banks");
-        megR.addEdge("ACTED_IN", joeVersustheVolcano, "roles", 
-            "DeDe, angelica Graynamore, Patricia Graynamore");
+        megR.addEdge("ACTED_IN", joeVersustheVolcano, "roles",
+                     "DeDe, angelica Graynamore, Patricia Graynamore");
         nathan.addEdge("ACTED_IN", joeVersustheVolcano, "roles", "Baw");
         johnS.addEdge("DIRECTED", joeVersustheVolcano, "score", 10);
 
         Vertex whenHarryMetSally = graph.addVertex(T.label, "movie", "title",
-             "When Harry Met Sally", "released", 1998);
+                                                   "When Harry Met Sally", "released", 1998);
 
         Vertex billyC = graph.addVertex(T.label, "person", "name", "Billy Crystal", "born", 1948);
         Vertex carrieF = graph.addVertex(T.label, "person", "name", "carrie Fisher", "born", 1956);
@@ -370,7 +369,7 @@ public class GraphOfTheMoviesExample {
         noraE.addEdge("WROTE", whenHarryMetSally, "score", 10);
 
         Vertex thatThingYouDo = graph.addVertex(T.label, "movie", "title",
-             "That Thing You Do", "released", 1996);
+                                                "That Thing You Do", "released", 1996);
 
         Vertex livT = graph.addVertex(T.label, "person", "name", "Liv Tyler", "born", 1977);
 
@@ -380,7 +379,7 @@ public class GraphOfTheMoviesExample {
         tomH.addEdge("DIRECTED", thatThingYouDo, "score", 10);
 
         Vertex theReplacements = graph.addVertex(T.label, "movie", "title",
-             "The Replacements", "released", 2000);
+                                                 "The Replacements", "released", 2000);
 
         Vertex brooke = graph.addVertex(T.label, "person", "name", "brooke Langton", "born", 1970);
         Vertex gene = graph.addVertex(T.label, "person", "name", "gene Hackman", "born", 1930);
@@ -394,10 +393,10 @@ public class GraphOfTheMoviesExample {
         howard.addEdge("DIRECTED", theReplacements, "score", 10);
 
         Vertex rescueDawn = graph.addVertex(T.label, "movie", "title",
-             "rescueDawn", "released", 2006);
+                                            "rescueDawn", "released", 2006);
 
         Vertex christianB = graph.addVertex(T.label, "person", "name",
-             "Christian Bale", "born", 1974);
+                                            "Christian Bale", "born", 1974);
         Vertex zachG = graph.addVertex(T.label, "person", "name", "Zach Grenier", "born", 1954);
 
         marshallB.addEdge("ACTED_IN", rescueDawn, "roles", "admiral");
@@ -407,7 +406,7 @@ public class GraphOfTheMoviesExample {
         wernerH.addEdge("DIRECTED", rescueDawn, "score", 10);
 
         Vertex theBirdcage = graph.addVertex(T.label, "movie", "title",
-             "The Birdcage", "released", 1996);
+                                             "The Birdcage", "released", 1996);
 
         Vertex mikeN = graph.addVertex(T.label, "person", "name", "Mike Nichols", "born", 1931);
 
@@ -417,10 +416,10 @@ public class GraphOfTheMoviesExample {
         mikeN.addEdge("DIRECTED", theBirdcage, "score", 10);
 
         Vertex unforgiven = graph.addVertex(T.label, "movie", "title",
-             "unforgiven", "released", 1992);
+                                            "unforgiven", "released", 1992);
 
         Vertex richardH = graph.addVertex(T.label, "person", "name",
-             "Richard Harris", "born", 1930);
+                                          "Richard Harris", "born", 1930);
         Vertex clintE = graph.addVertex(T.label, "person", "name", "Richard Harris", "born", 1930);
 
         richardH.addEdge("ACTED_IN", unforgiven, "roles", "English Bob");
@@ -429,7 +428,7 @@ public class GraphOfTheMoviesExample {
         clintE.addEdge("DIRECTED", unforgiven, "score", 10);
 
         Vertex johnnyMnemonic = graph.addVertex(T.label, "movie", "title",
-             "Johnny Mnemonic", "released", 1995);
+                                                "Johnny Mnemonic", "released", 1995);
 
         Vertex takeshi = graph.addVertex(T.label, "person", "name", "takeshi Kitano", "born", 1947);
         Vertex dina = graph.addVertex(T.label, "person", "name", "dina Meyer", "born", 1968);
@@ -443,24 +442,24 @@ public class GraphOfTheMoviesExample {
         robertL.addEdge("DIRECTED", johnnyMnemonic, "score", 10);
 
         Vertex cloudatlas = graph.addVertex(T.label, "movie", "title",
-             "Cloud atlas", "released", 2012);
+                                            "Cloud atlas", "released", 2012);
 
         Vertex halleB = graph.addVertex(T.label, "person", "name", "Halle Berry", "born", 1966);
         Vertex jimB = graph.addVertex(T.label, "person", "name", "Jim Broadbent", "born", 1949);
         Vertex tomT = graph.addVertex(T.label, "person", "name", "Tom Tykwer", "born", 1965);
         Vertex davidMitchell = graph.addVertex(T.label, "person", "name",
-             "David Mitchell", "born", 1969);
+                                               "David Mitchell", "born", 1969);
         Vertex stefanarndt = graph.addVertex(T.label, "person", "name",
-             "Stefan arndt", "born", 1961);
+                                             "Stefan arndt", "born", 1961);
 
         tomH.addEdge("ACTED_IN", cloudatlas, "roles",
-             "Zachry, Dr. Henry Goose, Isaac Sachs, Dermot Hoggins");
+                     "Zachry, Dr. Henry Goose, Isaac Sachs, Dermot Hoggins");
         hugo.addEdge("ACTED_IN", cloudatlas, "roles",
-             "Bill Smoke, Haskell Moore, Tadeusz Kesselring, Nurse Noakes," +
-                      " Boardman Mephi, Old Georgie");
+                     "Bill Smoke, Haskell Moore, Tadeusz Kesselring, Nurse Noakes," +
+                     " Boardman Mephi, Old Georgie");
         halleB.addEdge("ACTED_IN", cloudatlas, "roles", "Luisa Rey, Jocasta ayrs, Ovid, Meronym");
         jimB.addEdge("ACTED_IN", cloudatlas, "roles",
-             "Vyvyan ayrs, Captain Molyneux, Timothy Cavendish");
+                     "Vyvyan ayrs, Captain Molyneux, Timothy Cavendish");
         tomT.addEdge("DIRECTED", cloudatlas, "score", 10);
         lillyW.addEdge("DIRECTED", cloudatlas, "score", 10);
         lanaW.addEdge("DIRECTED", cloudatlas, "score", 10);
@@ -468,7 +467,7 @@ public class GraphOfTheMoviesExample {
         stefanarndt.addEdge("PRODUCED", cloudatlas, "score", 10);
 
         Vertex theDaVinciCode = graph.addVertex(T.label, "movie", "title",
-             "The Da Vinci Code", "released", 2006);
+                                                "The Da Vinci Code", "released", 2006);
 
         Vertex ianM = graph.addVertex(T.label, "person", "name", "Ian McKellen", "born", 1939);
         Vertex audreyT = graph.addVertex(T.label, "person", "name", "audrey Tautou", "born", 1976);
@@ -482,10 +481,10 @@ public class GraphOfTheMoviesExample {
         ronH.addEdge("DIRECTED", theDaVinciCode, "score", 10);
 
         Vertex vforVendetta = graph.addVertex(T.label, "movie", "title",
-             "The Da Vinci Code", "released", 2006);
+                                              "The Da Vinci Code", "released", 2006);
 
         Vertex natalieP = graph.addVertex(T.label, "person", "name",
-             "Natalie Portman", "born", 1981);
+                                          "Natalie Portman", "born", 1981);
         Vertex stephenR = graph.addVertex(T.label, "person", "name", "Stephen Rea", "born", 1946);
         Vertex johnH = graph.addVertex(T.label, "person", "name", "John Hurt", "born", 1940);
         Vertex benM = graph.addVertex(T.label, "person", "name", "Ben Miles", "born", 1967);
@@ -503,14 +502,14 @@ public class GraphOfTheMoviesExample {
         lanaW.addEdge("WROTE", vforVendetta, "score", 10);
 
         Vertex speedRacer = graph.addVertex(T.label, "movie", "title",
-             "Speed Racer", "released", 2008);
+                                            "Speed Racer", "released", 2008);
 
         Vertex matthewF = graph.addVertex(T.label, "person", "name", "Matthew Fox", "born", 1966);
         Vertex emileH = graph.addVertex(T.label, "person", "name", "Emile Hirsch", "born", 1985);
         Vertex johnG = graph.addVertex(T.label, "person", "name", "John Goodman", "born", 1940);
         Vertex susanS = graph.addVertex(T.label, "person", "name", "Susan Sarandon", "born", 1966);
         Vertex christinaR = graph.addVertex(T.label, "person", "name",
-             "Christina Ricci", "born", 1980);
+                                            "Christina Ricci", "born", 1980);
         Vertex rain = graph.addVertex(T.label, "person", "name", "Rain", "born", 1982);
 
         emileH.addEdge("ACTED_IN", speedRacer, "roles", "Speed Racer");
@@ -527,7 +526,7 @@ public class GraphOfTheMoviesExample {
         joelS.addEdge("PRODUCED", speedRacer, "score", 10);
 
         Vertex ninjaassassin = graph.addVertex(T.label, "movie", "title",
-             "Speed Racer", "released", 2009);
+                                               "Speed Racer", "released", 2009);
 
         Vertex naomieH = graph.addVertex(T.label, "person", "name", "Naomie Harris", "born", 1982);
 
@@ -541,15 +540,15 @@ public class GraphOfTheMoviesExample {
         joelS.addEdge("PRODUCED", ninjaassassin, "score", 10);
 
         Vertex theGreenMile = graph.addVertex(T.label, "movie", "title",
-             "The Green Mile", "released", 1999);
+                                              "The Green Mile", "released", 1999);
 
         Vertex michaelD = graph.addVertex(T.label, "person", "name",
-             "Michael Clarke Duncan", "born", 1957);
+                                          "Michael Clarke Duncan", "born", 1957);
         Vertex davidM = graph.addVertex(T.label, "person", "name", "David Morse", "born", 1953);
         Vertex samR = graph.addVertex(T.label, "person", "name", "Sam Rockwell", "born", 1968);
         Vertex garyS = graph.addVertex(T.label, "person", "name", "Gary Sinise", "born", 1955);
         Vertex patriciaC = graph.addVertex(T.label, "person", "name",
-             "Patricia Clarkson", "born", 1959);
+                                           "Patricia Clarkson", "born", 1959);
         Vertex frankD = graph.addVertex(T.label, "person", "name", "Frank Darabont", "born", 1959);
 
         tomH.addEdge("ACTED_IN", theGreenMile, "roles", "Paul Edgecomb");
@@ -563,7 +562,7 @@ public class GraphOfTheMoviesExample {
         frankD.addEdge("DIRECTED", theGreenMile, "score", 10);
 
         Vertex frostNixon = graph.addVertex(T.label, "movie", "title",
-             "Frost/Nixon", "released", 2008);
+                                            "Frost/Nixon", "released", 2008);
 
         Vertex frankL = graph.addVertex(T.label, "person", "name", "Frank Langella", "born", 1938);
         Vertex michaelS = graph.addVertex(T.label, "person", "name", "Michael Sheen", "born", 1969);
@@ -602,7 +601,7 @@ public class GraphOfTheMoviesExample {
         Vertex twister = graph.addVertex(T.label, "movie", "title", "twister", "released", 1996);
 
         Vertex philipH = graph.addVertex(T.label, "person", "name",
-             "Philip Seymour Hoffman", "born", 1967);
+                                         "Philip Seymour Hoffman", "born", 1967);
         Vertex janB = graph.addVertex(T.label, "person", "name", "Jan de Bont", "born", 1943);
 
         billPax.addEdge("ACTED_IN", twister, "roles", "Bill Harding");
@@ -614,14 +613,15 @@ public class GraphOfTheMoviesExample {
         Vertex castaway = graph.addVertex(T.label, "movie", "title", "Cast away", "released", 2000);
 
         Vertex robertZ = graph.addVertex(T.label, "person", "name",
-             "Robert Zemeckis", "born", 1951);
+                                         "Robert Zemeckis", "born", 1951);
 
         tomH.addEdge("ACTED_IN", castaway, "roles", "Chuck Noland");
         helenH.addEdge("ACTED_IN", castaway, "roles", "Kelly Frears");
         robertZ.addEdge("DIRECTED", castaway, "score", 10);
 
         Vertex oneFlewOvertheCuckoosNest = graph.addVertex(T.label, "movie", "title",
-             "One Flew Over the Cuckoo's Nest", "released", 1975);
+                                                           "One Flew Over the Cuckoo's Nest",
+                                                           "released", 1975);
 
         Vertex milosF = graph.addVertex(T.label, "person", "name", "Milos Forman", "born", 1932);
 
@@ -630,7 +630,7 @@ public class GraphOfTheMoviesExample {
         milosF.addEdge("DIRECTED", oneFlewOvertheCuckoosNest, "score", 10);
 
         Vertex somethingsGottaGive = graph.addVertex(T.label, "movie", "title",
-             "Something's Gotta Give", "released", 2003);
+                                                     "Something's Gotta Give", "released", 2003);
 
         Vertex dianeK = graph.addVertex(T.label, "person", "name", "Diane Keaton", "born", 1946);
         Vertex nancyM = graph.addVertex(T.label, "person", "name", "Nancy Meyers", "born", 1949);
@@ -643,7 +643,7 @@ public class GraphOfTheMoviesExample {
         nancyM.addEdge("WROTE", somethingsGottaGive, "score", 10);
 
         Vertex bicentennialMan = graph.addVertex(T.label, "movie", "title",
-             "Bicentennial Man", "released", 2000);
+                                                 "Bicentennial Man", "released", 2000);
 
         Vertex chrisC = graph.addVertex(T.label, "person", "name", "Chris Columbus", "born", 1958);
 
@@ -652,7 +652,7 @@ public class GraphOfTheMoviesExample {
         chrisC.addEdge("DIRECTED", bicentennialMan, "score", 10);
 
         Vertex charlieWilsonsWar = graph.addVertex(T.label, "movie", "title",
-             "Charlie Wilson's War", "released", 2007);
+                                                   "Charlie Wilson's War", "released", 2007);
 
         Vertex juliaR = graph.addVertex(T.label, "person", "name", "Julia Roberts", "born", 1967);
 
@@ -662,14 +662,14 @@ public class GraphOfTheMoviesExample {
         mikeN.addEdge("DIRECTED", charlieWilsonsWar, "score", 10);
 
         Vertex thePolarExpress = graph.addVertex(T.label, "movie", "title",
-             "The Polar Express", "released", 2004);
+                                                 "The Polar Express", "released", 2004);
 
         tomH.addEdge("ACTED_IN", thePolarExpress, "roles", "Hero Boy");
 
         robertZ.addEdge("DIRECTED", thePolarExpress, "score", 10);
 
         Vertex aLeagueofTheirOwn = graph.addVertex(T.label, "movie", "title",
-             "a League of Their Own", "released", 1992);
+                                                   "a League of Their Own", "released", 1992);
 
         Vertex madonna = graph.addVertex(T.label, "person", "name", "madonna", "born", 1954);
         Vertex geenaD = graph.addVertex(T.label, "person", "name", "Geena Davis", "born", 1956);
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample1.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample1.java
index 943e43f6c..f015b5956 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample1.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample1.java
@@ -21,12 +21,12 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+
 import com.datastax.driver.core.exceptions.NoHostAvailableException;
 
 /**
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample2.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample2.java
index 4316eaa2f..5dc50f80f 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample2.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample2.java
@@ -21,12 +21,12 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+
 import com.datastax.driver.core.exceptions.NoHostAvailableException;
 
 /**
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample3.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample3.java
index 8fb9e1d0c..10ef178d2 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample3.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample3.java
@@ -17,13 +17,12 @@
 
 package org.apache.hugegraph.example;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
 
 /**
  * Perf test for: insert vertices with indexes in order
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample4.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample4.java
index 6dda80465..c686e360d 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample4.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExample4.java
@@ -19,11 +19,10 @@ package org.apache.hugegraph.example;
 
 import java.util.List;
 
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
 
 /**
  * Perf test for: query vertices with indexes and limit
@@ -34,6 +33,7 @@ public class PerfExample4 extends PerfExample3 {
 
     /**
      * Main method
+     *
      * @param args 3 arguments, 1st should be 1, meaning single thread,
      *             product of 2nd and 3rd is total number of "person" vertices
      * @throws InterruptedException
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExampleBase.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExampleBase.java
index cf93f7bb8..684866674 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExampleBase.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/PerfExampleBase.java
@@ -96,7 +96,7 @@ public abstract class PerfExampleBase {
      * @throws Exception execute may throw Exception
      */
     public void testInsertPerf(GraphManager graph, int threadCount, int times, int multiple)
-        throws Exception {
+            throws Exception {
         // Total vertices/edges
         long n = (long) threadCount * times * multiple;
         long vertices = (PERSON_NUM + SOFTWARE_NUM) * n;
@@ -113,7 +113,7 @@ public abstract class PerfExampleBase {
     }
 
     public void testQueryVertexPerf(GraphManager graph, int threadCount, int times, int multiple)
-        throws Exception {
+            throws Exception {
         long cost = this.execute(graph, i -> {
             this.testQueryVertex(graph, threadCount, i, multiple);
         }, threadCount);
@@ -125,7 +125,7 @@ public abstract class PerfExampleBase {
     }
 
     public void testQueryEdgePerf(GraphManager graph, int threadCount, int times, int multiple)
-        throws Exception {
+            throws Exception {
         long cost = this.execute(graph, i -> {
             this.testQueryEdge(graph, threadCount, i, multiple);
         }, threadCount);
@@ -236,6 +236,7 @@ public abstract class PerfExampleBase {
     }
 
     protected static class GraphManager {
+
         private final HugeGraph hugegraph;
         private final Cache<Id, Object> cache = CacheManager.instance().cache("perf-test");
 
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/TaskExample.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/TaskExample.java
index 3259cc33c..2afa719b9 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/TaskExample.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/TaskExample.java
@@ -20,8 +20,6 @@ package org.apache.hugegraph.example;
 import java.util.Iterator;
 
 import org.apache.commons.collections.IteratorUtils;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
@@ -32,6 +30,7 @@ import org.apache.hugegraph.task.TaskScheduler;
 import org.apache.hugegraph.task.TaskStatus;
 import org.apache.hugegraph.testutil.Whitebox;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class TaskExample {
 
diff --git a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ThreadRangePerfTest.java b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ThreadRangePerfTest.java
index aa6c8dc88..d2da5014a 100644
--- a/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ThreadRangePerfTest.java
+++ b/hugegraph-server/hugegraph-example/src/main/java/org/apache/hugegraph/example/ThreadRangePerfTest.java
@@ -17,10 +17,9 @@
 
 package org.apache.hugegraph.example;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeFactory;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class ThreadRangePerfTest {
 
diff --git a/hugegraph-server/hugegraph-example/src/main/resources/log4j2.xml b/hugegraph-server/hugegraph-example/src/main/resources/log4j2.xml
index fd614545e..ba2761f6c 100644
--- a/hugegraph-server/hugegraph-example/src/main/resources/log4j2.xml
+++ b/hugegraph-server/hugegraph-example/src/main/resources/log4j2.xml
@@ -30,14 +30,14 @@
 
         <!-- Normal server log config -->
         <RollingRandomAccessFile name="file" fileName="${LOG_PATH}/${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
-            immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd}-%i.log"
+                                 immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} [%t] [%p] %c{1.} - %m%n"/>
             <!-- Trigger after exceeding 1day or 50MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="50MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 5 files per day & auto delete after over 2GB or 100 files -->
             <DefaultRolloverStrategy max="5">
@@ -45,8 +45,8 @@
                     <IfFileName glob="*/*.log"/>
                     <!-- Limit log amount & size -->
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="2GB" />
-                        <IfAccumulatedFileCount exceeds="100" />
+                        <IfAccumulatedFileSize exceeds="2GB"/>
+                        <IfAccumulatedFileCount exceeds="100"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>
@@ -54,15 +54,15 @@
 
         <!-- Separate & compress audit log, buffer size is 512KB -->
         <RollingRandomAccessFile name="audit" fileName="${LOG_PATH}/audit-${FILE_NAME}.log"
-            filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
-            bufferSize="524288" immediateFlush="false">
+                                 filePattern="${LOG_PATH}/$${date:yyyy-MM}/audit-${FILE_NAME}-%d{yyyy-MM-dd-HH}-%i.gz"
+                                 bufferSize="524288" immediateFlush="false">
             <ThresholdFilter level="TRACE" onMatch="ACCEPT" onMismatch="DENY"/>
             <!-- Use simple format for audit log to speed up -->
             <PatternLayout pattern="%-d{yyyy-MM-dd HH:mm:ss} - %m%n"/>
             <!-- Trigger after exceeding 1hour or 500MB -->
             <Policies>
                 <SizeBasedTriggeringPolicy size="500MB"/>
-                <TimeBasedTriggeringPolicy interval="1" modulate="true" />
+                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
             </Policies>
             <!-- Keep 2 files per hour & auto delete [after 60 days] or [over 5GB or 500 files] -->
             <DefaultRolloverStrategy max="2">
@@ -70,8 +70,8 @@
                     <IfFileName glob="*/*.gz"/>
                     <IfLastModified age="60d"/>
                     <IfAny>
-                        <IfAccumulatedFileSize exceeds="5GB" />
-                        <IfAccumulatedFileCount exceeds="500" />
+                        <IfAccumulatedFileSize exceeds="5GB"/>
+                        <IfAccumulatedFileCount exceeds="500"/>
                     </IfAny>
                 </Delete>
             </DefaultRolloverStrategy>


(incubator-hugegraph) 03/03: fix: format and clean code in modules (#2439)

Posted by vg...@apache.org.
This is an automated email from the ASF dual-hosted git repository.

vgalaxies pushed a commit to branch pd-store
in repository https://gitbox.apache.org/repos/asf/incubator-hugegraph.git

commit 5551ec17f23916124a4c3ac8fcd9ec0a5600a9f1
Author: M <87...@users.noreply.github.com>
AuthorDate: Tue Feb 20 17:22:54 2024 +0800

    fix: format and clean code in modules (#2439)
    
    Format & clean code in submodels:
    
    1. API
    2. Scylladb
    3. Postgresql
    4. Rocksdb
    5. Palo
    6. Mysql
    7. Hbase
    8. Cassandra
    9. Test
    
    ---------
    
    Co-authored-by: imbajin <ji...@apache.org>
---
 .../main/java/org/apache/hugegraph/api/API.java    |  15 +-
 .../org/apache/hugegraph/api/arthas/ArthasAPI.java |   1 -
 .../org/apache/hugegraph/api/auth/AccessAPI.java   |  36 +-
 .../org/apache/hugegraph/api/auth/BelongAPI.java   |  34 +-
 .../org/apache/hugegraph/api/auth/GroupAPI.java    |  34 +-
 .../org/apache/hugegraph/api/auth/ProjectAPI.java  |  36 +-
 .../org/apache/hugegraph/api/auth/TargetAPI.java   |  32 +-
 .../org/apache/hugegraph/api/auth/UserAPI.java     |  36 +-
 .../org/apache/hugegraph/api/cypher/CypherAPI.java |   1 -
 .../apache/hugegraph/api/cypher/CypherClient.java  |  26 +-
 .../apache/hugegraph/api/cypher/CypherModel.java   |   2 +
 .../hugegraph/api/filter/AuthenticationFilter.java |  10 +-
 .../hugegraph/api/filter/CompressInterceptor.java  |  19 +-
 .../api/filter/DecompressInterceptor.java          |   3 +-
 .../hugegraph/api/filter/ExceptionFilter.java      |  52 +--
 .../hugegraph/api/filter/LoadDetectFilter.java     |  35 +-
 .../hugegraph/api/filter/LoadReleaseFilter.java    |   4 +-
 .../hugegraph/api/filter/RedirectFilter.java       |   1 +
 .../apache/hugegraph/api/filter/StatusFilter.java  |   3 +-
 .../org/apache/hugegraph/api/graph/BatchAPI.java   |  37 +-
 .../org/apache/hugegraph/api/graph/EdgeAPI.java    | 166 ++++----
 .../org/apache/hugegraph/api/graph/VertexAPI.java  |  98 ++---
 .../api/gremlin/AbstractJerseyRestClient.java      |   2 +-
 .../apache/hugegraph/api/gremlin/GremlinAPI.java   |  16 +-
 .../hugegraph/api/gremlin/GremlinQueryAPI.java     |   1 +
 .../org/apache/hugegraph/api/job/AlgorithmAPI.java |   1 -
 .../org/apache/hugegraph/api/job/GremlinAPI.java   |   4 +-
 .../java/org/apache/hugegraph/api/job/TaskAPI.java |  12 +-
 .../apache/hugegraph/api/metrics/MetricsAPI.java   |   1 -
 .../apache/hugegraph/api/profile/GraphsAPI.java    |  48 +--
 .../apache/hugegraph/api/profile/ProfileAPI.java   |  31 +-
 .../apache/hugegraph/api/profile/VersionAPI.java   |  19 +-
 .../hugegraph/api/profile/WhiteIpListAPI.java      |   6 +-
 .../org/apache/hugegraph/api/raft/RaftAPI.java     |  34 +-
 .../hugegraph/api/traversers/AdamicAdarAPI.java    |  21 +-
 .../apache/hugegraph/api/traversers/CountAPI.java  |  22 +-
 .../hugegraph/api/traversers/EdgeExistenceAPI.java |   1 -
 .../hugegraph/api/traversers/NeighborRankAPI.java  |  22 +-
 .../hugegraph/api/traversers/PersonalRankAPI.java  |  20 +-
 .../api/traversers/ResourceAllocationAPI.java      |  21 +-
 .../apache/hugegraph/api/traversers/Vertices.java  |  10 +-
 .../hugegraph/api/variables/VariablesAPI.java      |  22 +-
 .../apache/hugegraph/auth/ConfigAuthenticator.java |   5 +-
 .../hugegraph/auth/ContextGremlinServer.java       |   8 +-
 .../apache/hugegraph/auth/HugeAuthenticator.java   |  10 +-
 .../hugegraph/auth/HugeFactoryAuthProxy.java       | 441 +++++++++++++++++----
 .../apache/hugegraph/auth/HugeGraphAuthProxy.java  |  62 +--
 .../hugegraph/auth/StandardAuthenticator.java      |   7 +-
 .../hugegraph/auth/WsAndHttpBasicAuthHandler.java  |  10 +-
 .../org/apache/hugegraph/config/ServerOptions.java |  48 +--
 .../org/apache/hugegraph/core/GraphManager.java    |  16 +-
 .../apache/hugegraph/define/UpdateStrategy.java    |   9 +-
 .../apache/hugegraph/metrics/MetricsModule.java    |   2 +-
 .../apache/hugegraph/metrics/ServerReporter.java   |   5 +-
 .../apache/hugegraph/metrics/SystemMetrics.java    |   5 +-
 .../hugegraph/opencypher/CypherOpProcessor.java    |  38 +-
 .../apache/hugegraph/opencypher/CypherPlugin.java  |  28 +-
 .../hugegraph/rpc/RpcClientProviderWithAuth.java   |   3 +-
 .../apache/hugegraph/server/ApplicationConfig.java |  32 +-
 .../org/apache/hugegraph/server/RestServer.java    |  21 +-
 .../store/cassandra/CassandraEntryIterator.java    |   2 +-
 .../backend/store/cassandra/CassandraMetrics.java  |   6 +-
 .../store/cassandra/CassandraSerializer.java       |   1 +
 .../store/cassandra/CassandraSessionPool.java      |   1 +
 .../backend/store/cassandra/CassandraShard.java    |  42 +-
 .../backend/store/cassandra/CassandraStore.java    |  48 ++-
 .../backend/store/cassandra/CassandraTable.java    |  35 +-
 .../backend/store/cassandra/CassandraTables.java   |   8 +-
 hugegraph-server/hugegraph-dist/docker/README.md   |   2 +-
 .../backend/store/hbase/HbaseMetrics.java          |  10 +-
 .../backend/store/hbase/HbaseOptions.java          |   2 +-
 .../backend/store/hbase/HbaseSerializer.java       |   3 +-
 .../backend/store/hbase/HbaseSessions.java         |  18 +-
 .../hugegraph/backend/store/hbase/HbaseStore.java  |  55 +--
 .../hugegraph/backend/store/hbase/HbaseTable.java  |  16 +-
 .../hugegraph/backend/store/hbase/HbaseTables.java |   3 +-
 .../backend/store/mysql/MysqlEntryIterator.java    |   4 +-
 .../backend/store/mysql/MysqlMetrics.java          |   1 +
 .../backend/store/mysql/MysqlOptions.java          |   6 +-
 .../backend/store/mysql/MysqlSerializer.java       |   3 +-
 .../backend/store/mysql/MysqlSessions.java         |  20 +-
 .../hugegraph/backend/store/mysql/MysqlStore.java  |  13 +-
 .../hugegraph/backend/store/mysql/MysqlTable.java  |  24 +-
 .../hugegraph/backend/store/mysql/MysqlTables.java |  21 +-
 .../backend/store/mysql/WhereBuilder.java          |  34 +-
 .../hugegraph/backend/store/palo/PaloFile.java     |   2 +-
 .../hugegraph/backend/store/palo/PaloSessions.java |   6 +-
 .../hugegraph/backend/store/palo/PaloStore.java    |   3 +-
 .../backend/store/palo/PaloStoreProvider.java      |   4 +-
 .../hugegraph/backend/store/palo/PaloTable.java    |   5 +-
 .../hugegraph/backend/store/palo/PaloTables.java   |  10 +-
 .../store/postgresql/PostgresqlSerializer.java     |   5 +-
 .../store/postgresql/PostgresqlSessions.java       |  34 +-
 .../store/postgresql/PostgresqlStoreProvider.java  |   9 +-
 .../backend/store/postgresql/PostgresqlTable.java  |   6 +-
 .../backend/store/postgresql/PostgresqlTables.java |  34 +-
 .../backend/store/rocksdb/RocksDBStdSessions.java  |  36 +-
 .../backend/store/rocksdb/RocksDBStore.java        |   4 +-
 .../backend/store/rocksdb/RocksDBTable.java        |   2 +-
 .../store/rocksdbsst/RocksDBSstSessions.java       |   4 +-
 .../backend/store/rocksdbsst/RocksDBSstStore.java  |   2 +-
 .../backend/store/scylladb/ScyllaDBMetrics.java    |   1 -
 .../store/scylladb/ScyllaDBStoreProvider.java      |   9 +-
 .../store/scylladb/ScyllaDBTablesWithMV.java       |  51 +--
 hugegraph-server/hugegraph-test/pom.xml            |   2 +-
 .../org/apache/hugegraph/api/ApiTestSuite.java     |  32 +-
 .../java/org/apache/hugegraph/api/BaseApiTest.java | 274 ++++++-------
 .../org/apache/hugegraph/api/CypherApiTest.java    |   2 +-
 .../java/org/apache/hugegraph/api/EdgeApiTest.java | 176 ++++----
 .../org/apache/hugegraph/api/EdgeLabelApiTest.java |  96 ++---
 .../org/apache/hugegraph/api/GremlinApiTest.java   | 193 ++++-----
 .../apache/hugegraph/api/IndexLabelApiTest.java    | 102 ++---
 .../org/apache/hugegraph/api/LoginApiTest.java     |   9 +-
 .../org/apache/hugegraph/api/ProjectApiTest.java   |   6 +-
 .../apache/hugegraph/api/PropertyKeyApiTest.java   |  40 +-
 .../java/org/apache/hugegraph/api/TaskApiTest.java |  10 +-
 .../java/org/apache/hugegraph/api/UserApiTest.java |  10 +-
 .../org/apache/hugegraph/api/VertexApiTest.java    |  48 +--
 .../apache/hugegraph/api/VertexLabelApiTest.java   |  72 ++--
 .../api/traversers/AdamicAdarAPITest.java          |   6 +-
 .../api/traversers/AllShortestPathsApiTest.java    |   2 +-
 .../hugegraph/api/traversers/CountApiTest.java     |   6 +-
 .../api/traversers/CrosspointsApiTest.java         |   9 +-
 .../traversers/CustomizedCrosspointsApiTest.java   |   4 +-
 .../hugegraph/api/traversers/EdgesApiTest.java     |   9 +-
 .../api/traversers/FusiformSimilarityApiTest.java  |   4 +-
 .../traversers/MultiNodeShortestPathApiTest.java   |   4 +-
 .../api/traversers/NeighborRankApiTest.java        |   4 +-
 .../hugegraph/api/traversers/PathsApiTest.java     |   6 +-
 .../api/traversers/PersonalRankApiTest.java        |   4 +-
 .../api/traversers/ResourceAllocationAPITest.java  |   6 +-
 .../hugegraph/api/traversers/RingsApiTest.java     |   5 +-
 .../api/traversers/ShortestPathApiTest.java        |   5 +-
 .../api/traversers/TemplatePathsApiTest.java       |   5 +-
 .../api/traversers/TraversersApiTestSuite.java     |  45 ++-
 .../traversers/WeightedShortestPathApiTest.java    |   5 +-
 .../java/org/apache/hugegraph/core/AuthTest.java   | 100 ++---
 .../org/apache/hugegraph/core/CoreTestSuite.java   |  27 +-
 .../org/apache/hugegraph/core/EdgeCoreTest.java    | 319 +++++++--------
 .../apache/hugegraph/core/EdgeLabelCoreTest.java   |  48 +--
 .../apache/hugegraph/core/IndexLabelCoreTest.java  |  72 ++--
 .../apache/hugegraph/core/PropertyCoreTest.java    |  22 +-
 .../apache/hugegraph/core/PropertyKeyCoreTest.java |  12 +-
 .../org/apache/hugegraph/core/RamTableTest.java    |  31 +-
 .../org/apache/hugegraph/core/RestoreCoreTest.java | 127 +++---
 .../core/RoleElectionStateMachineTest.java         |   2 +-
 .../org/apache/hugegraph/core/SchemaCoreTest.java  |   5 +-
 .../org/apache/hugegraph/core/TaskCoreTest.java    | 157 ++++----
 .../org/apache/hugegraph/core/VertexCoreTest.java  | 390 +++++++++---------
 .../apache/hugegraph/core/VertexLabelCoreTest.java |  40 +-
 .../org/apache/hugegraph/testutil/FakeObjects.java |   3 +-
 .../java/org/apache/hugegraph/testutil/Utils.java  |   7 +-
 .../hugegraph/tinkerpop/ProcessBasicSuite.java     | 286 ++++++-------
 .../hugegraph/tinkerpop/ProcessStandardTest.java   |   1 +
 .../hugegraph/tinkerpop/StructureBasicSuite.java   |  61 +--
 .../hugegraph/tinkerpop/StructureStandardTest.java |   1 +
 .../org/apache/hugegraph/tinkerpop/TestGraph.java  |   5 +-
 .../hugegraph/tinkerpop/TestGraphFactory.java      |   2 +-
 .../hugegraph/tinkerpop/TestGraphProvider.java     |  50 +--
 .../tinkerpop/tests/HugeGraphWriteTest.java        |  11 +-
 .../org/apache/hugegraph/unit/BaseUnitTest.java    |   7 +-
 .../org/apache/hugegraph/unit/FakeObjects.java     |   9 +-
 .../org/apache/hugegraph/unit/UnitTestSuite.java   | 137 +++----
 .../hugegraph/unit/cache/CacheManagerTest.java     |  20 +-
 .../org/apache/hugegraph/unit/cache/CacheTest.java |  16 +-
 .../unit/cache/CachedGraphTransactionTest.java     |   9 +-
 .../unit/cache/CachedSchemaTransactionTest.java    |   8 +-
 .../apache/hugegraph/unit/cache/RamTableTest.java  |   9 +-
 .../hugegraph/unit/cassandra/CassandraTest.java    |  20 +-
 .../apache/hugegraph/unit/core/AnalyzerTest.java   |  11 +-
 .../hugegraph/unit/core/BackendMutationTest.java   |   7 +-
 .../hugegraph/unit/core/BackendStoreInfoTest.java  |   7 +-
 .../unit/core/ConditionQueryFlattenTest.java       |   8 +-
 .../apache/hugegraph/unit/core/ConditionTest.java  |   4 +-
 .../apache/hugegraph/unit/core/DataTypeTest.java   |   5 +-
 .../apache/hugegraph/unit/core/DirectionsTest.java |   5 +-
 .../apache/hugegraph/unit/core/ExceptionTest.java  |   4 +-
 .../apache/hugegraph/unit/core/LocksTableTest.java |  10 +-
 .../apache/hugegraph/unit/core/PageStateTest.java  |   3 +-
 .../org/apache/hugegraph/unit/core/QueryTest.java  |   4 +-
 .../org/apache/hugegraph/unit/core/RangeTest.java  |  11 +-
 .../hugegraph/unit/core/RolePermissionTest.java    |  46 ++-
 .../apache/hugegraph/unit/core/RowLockTest.java    |  11 +-
 .../hugegraph/unit/core/SecurityManagerTest.java   |  14 +-
 .../apache/hugegraph/unit/core/SerialEnumTest.java |   3 +-
 .../hugegraph/unit/core/SystemSchemaStoreTest.java |   5 +-
 .../hugegraph/unit/core/TraversalUtilTest.java     |  19 +-
 .../org/apache/hugegraph/unit/id/EdgeIdTest.java   |  10 +-
 .../java/org/apache/hugegraph/unit/id/IdTest.java  |  12 +-
 .../org/apache/hugegraph/unit/id/IdUtilTest.java   |   5 +-
 .../hugegraph/unit/id/SplicingIdGeneratorTest.java |  16 +-
 .../apache/hugegraph/unit/mysql/MysqlUtilTest.java |   3 +-
 .../hugegraph/unit/mysql/WhereBuilderTest.java     |   4 +-
 .../hugegraph/unit/rocksdb/RocksDBPerfTest.java    |   4 +-
 .../hugegraph/unit/rocksdb/RocksDBSessionTest.java |  23 +-
 .../hugegraph/unit/serializer/BytesBufferTest.java |  10 +-
 .../unit/serializer/SerializerFactoryTest.java     |   5 +-
 .../unit/serializer/StoreSerializerTest.java       |   7 +-
 .../unit/serializer/TableBackendEntryTest.java     |   4 +-
 .../unit/serializer/TextBackendEntryTest.java      |   4 +-
 .../hugegraph/unit/util/CompressUtilTest.java      |   6 +-
 .../apache/hugegraph/unit/util/JsonUtilTest.java   |  33 +-
 .../hugegraph/unit/util/RateLimiterTest.java       |   5 +-
 .../hugegraph/unit/util/StringEncodingTest.java    |  13 +-
 .../apache/hugegraph/unit/util/VersionTest.java    |   5 +-
 .../util/collection/CollectionFactoryTest.java     |  12 +-
 .../hugegraph/unit/util/collection/IdSetTest.java  |   9 +-
 .../unit/util/collection/Int2IntsMapTest.java      |  47 ++-
 .../hugegraph/unit/util/collection/IntMapTest.java |  18 +-
 .../hugegraph/unit/util/collection/IntSetTest.java |  11 +-
 .../unit/util/collection/ObjectIntMappingTest.java |   9 +-
 .../hugegraph-test/src/main/resources/log4j2.xml   |  26 +-
 .../map/MapRandomGetPutThroughputTest.java         |   8 +-
 213 files changed, 3152 insertions(+), 2899 deletions(-)

diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/API.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/API.java
index 444549a80..b7f564e8d 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/API.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/API.java
@@ -48,22 +48,23 @@ public class API {
     public static final String TEXT_PLAIN = MediaType.TEXT_PLAIN;
     public static final String APPLICATION_JSON = MediaType.APPLICATION_JSON;
     public static final String APPLICATION_JSON_WITH_CHARSET =
-                               APPLICATION_JSON + ";charset=" + CHARSET;
-    public static final String APPLICATION_TEXT_WITH_CHARSET = MediaType.TEXT_PLAIN + ";charset=" + CHARSET;
+            APPLICATION_JSON + ";charset=" + CHARSET;
+    public static final String APPLICATION_TEXT_WITH_CHARSET =
+            MediaType.TEXT_PLAIN + ";charset=" + CHARSET;
     public static final String JSON = MediaType.APPLICATION_JSON_TYPE
-                                               .getSubtype();
+            .getSubtype();
     public static final String ACTION_APPEND = "append";
     public static final String ACTION_ELIMINATE = "eliminate";
     public static final String ACTION_CLEAR = "clear";
     protected static final Logger LOG = Log.logger(API.class);
     private static final Meter SUCCEED_METER =
-                         MetricsUtil.registerMeter(API.class, "commit-succeed");
+            MetricsUtil.registerMeter(API.class, "commit-succeed");
     private static final Meter ILLEGAL_ARG_ERROR_METER =
-                         MetricsUtil.registerMeter(API.class, "illegal-arg");
+            MetricsUtil.registerMeter(API.class, "illegal-arg");
     private static final Meter EXPECTED_ERROR_METER =
-                         MetricsUtil.registerMeter(API.class, "expected-error");
+            MetricsUtil.registerMeter(API.class, "expected-error");
     private static final Meter UNKNOWN_ERROR_METER =
-                         MetricsUtil.registerMeter(API.class, "unknown-error");
+            MetricsUtil.registerMeter(API.class, "unknown-error");
 
     public static HugeGraph graph(GraphManager manager, String graph) {
         HugeGraph g = manager.graph(graph);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/arthas/ArthasAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/arthas/ArthasAPI.java
index cb819057c..7cd9a98f8 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/arthas/ArthasAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/arthas/ArthasAPI.java
@@ -29,7 +29,6 @@ import com.taobao.arthas.agent.attach.ArthasAgent;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
-
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.PUT;
 import jakarta.ws.rs.Path;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/AccessAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/AccessAPI.java
index 75dbad7fb..5c07681da 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/AccessAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/AccessAPI.java
@@ -19,37 +19,37 @@ package org.apache.hugegraph.api.auth;
 
 import java.util.List;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DELETE;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.PUT;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Path;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.filter.StatusFilter.Status;
 import org.apache.hugegraph.auth.HugeAccess;
 import org.apache.hugegraph.auth.HugePermission;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/auth/accesses")
 @Singleton
 @Tag(name = "AccessAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/BelongAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/BelongAPI.java
index 7880e434e..da66c0cec 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/BelongAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/BelongAPI.java
@@ -19,7 +19,24 @@ package org.apache.hugegraph.api.auth;
 
 import java.util.List;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.api.filter.StatusFilter.Status;
+import org.apache.hugegraph.auth.HugeBelong;
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.codahale.metrics.annotation.Timed;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.DELETE;
 import jakarta.ws.rs.DefaultValue;
@@ -32,23 +49,6 @@ import jakarta.ws.rs.Produces;
 import jakarta.ws.rs.QueryParam;
 import jakarta.ws.rs.core.Context;
 
-import jakarta.inject.Singleton;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.api.filter.StatusFilter.Status;
-import org.apache.hugegraph.auth.HugeBelong;
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
-import com.codahale.metrics.annotation.Timed;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-import com.fasterxml.jackson.annotation.JsonProperty;
-
 @Path("graphs/{graph}/auth/belongs")
 @Singleton
 @Tag(name = "BelongAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/GroupAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/GroupAPI.java
index e70c88d31..f0ac7f6ea 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/GroupAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/GroupAPI.java
@@ -19,7 +19,24 @@ package org.apache.hugegraph.api.auth;
 
 import java.util.List;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.api.filter.StatusFilter.Status;
+import org.apache.hugegraph.auth.HugeGroup;
+import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.codahale.metrics.annotation.Timed;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.DELETE;
 import jakarta.ws.rs.DefaultValue;
@@ -32,23 +49,6 @@ import jakarta.ws.rs.Produces;
 import jakarta.ws.rs.QueryParam;
 import jakarta.ws.rs.core.Context;
 
-import jakarta.inject.Singleton;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.api.filter.StatusFilter.Status;
-import org.apache.hugegraph.auth.HugeGroup;
-import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
-import com.codahale.metrics.annotation.Timed;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-import com.fasterxml.jackson.annotation.JsonProperty;
-
 @Path("graphs/{graph}/auth/groups")
 @Singleton
 @Tag(name = "GroupAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/ProjectAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/ProjectAPI.java
index 1f048e9a0..c90323ef9 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/ProjectAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/ProjectAPI.java
@@ -21,39 +21,39 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DELETE;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.PUT;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
 import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.lang.StringUtils;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.filter.StatusFilter.Status;
 import org.apache.hugegraph.auth.AuthManager;
 import org.apache.hugegraph.auth.HugeProject;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/auth/projects")
 @Singleton
 @Tag(name = "ProjectAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/TargetAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/TargetAPI.java
index c13fff151..eb52e455c 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/TargetAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/TargetAPI.java
@@ -20,6 +20,22 @@ package org.apache.hugegraph.api.auth;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.api.filter.StatusFilter.Status;
+import org.apache.hugegraph.auth.HugeTarget;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.codahale.metrics.annotation.Timed;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
@@ -34,22 +50,6 @@ import jakarta.ws.rs.Produces;
 import jakarta.ws.rs.QueryParam;
 import jakarta.ws.rs.core.Context;
 
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.api.filter.StatusFilter.Status;
-import org.apache.hugegraph.auth.HugeTarget;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.JsonUtil;
-import org.apache.hugegraph.util.Log;
-import com.codahale.metrics.annotation.Timed;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-import com.fasterxml.jackson.annotation.JsonProperty;
-
 @Path("graphs/{graph}/auth/targets")
 @Singleton
 @Tag(name = "TargetAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/UserAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/UserAPI.java
index 25d812104..ed26573f8 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/UserAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/auth/UserAPI.java
@@ -19,39 +19,39 @@ package org.apache.hugegraph.api.auth;
 
 import java.util.List;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DELETE;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.PUT;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
 import org.apache.commons.lang3.StringUtils;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.Checkable;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.filter.StatusFilter.Status;
 import org.apache.hugegraph.auth.HugeUser;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.Checkable;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.StringEncoding;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/auth/users")
 @Singleton
 @Tag(name = "UserAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherAPI.java
index c8cc3929f..b24169aaa 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherAPI.java
@@ -34,7 +34,6 @@ import org.slf4j.Logger;
 import com.codahale.metrics.annotation.Timed;
 
 import io.swagger.v3.oas.annotations.tags.Tag;
-
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.GET;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherClient.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherClient.java
index eb3a86ff6..92ae18c54 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherClient.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherClient.java
@@ -17,16 +17,6 @@
 
 package org.apache.hugegraph.api.cypher;
 
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
-import org.apache.commons.configuration2.Configuration;
-import org.apache.tinkerpop.gremlin.driver.*;
-import org.apache.tinkerpop.gremlin.driver.message.RequestMessage;
-import org.slf4j.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
@@ -35,6 +25,20 @@ import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 import java.util.function.Supplier;
 
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+import org.apache.commons.configuration2.Configuration;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.driver.Client;
+import org.apache.tinkerpop.gremlin.driver.Cluster;
+import org.apache.tinkerpop.gremlin.driver.Result;
+import org.apache.tinkerpop.gremlin.driver.ResultSet;
+import org.apache.tinkerpop.gremlin.driver.Tokens;
+import org.apache.tinkerpop.gremlin.driver.message.RequestMessage;
+import org.slf4j.Logger;
+
 @ThreadSafe
 public final class CypherClient {
 
@@ -93,7 +97,7 @@ public final class CypherClient {
     }
 
     private List<Object> doQueryList(Client client, RequestMessage request)
-        throws ExecutionException, InterruptedException {
+            throws ExecutionException, InterruptedException {
         ResultSet results = client.submitAsync(request).get();
 
         Iterator<Result> iter = results.iterator();
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherModel.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherModel.java
index c85a0aff0..cd5a76923 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherModel.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherModel.java
@@ -50,12 +50,14 @@ public class CypherModel {
     }
 
     public static class Status {
+
         public String message = "";
         public int code;
         public Map<String, Object> attributes = Collections.EMPTY_MAP;
     }
 
     private static class Result {
+
         public List<Object> data;
         public Map<String, Object> meta = Collections.EMPTY_MAP;
     }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/AuthenticationFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/AuthenticationFilter.java
index ba69fd9c0..fffe5ef9e 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/AuthenticationFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/AuthenticationFilter.java
@@ -143,8 +143,8 @@ public class AuthenticationFilter implements ContainerRequestFilter {
         String auth = context.getHeaderString(HttpHeaders.AUTHORIZATION);
         if (auth == null) {
             throw new NotAuthorizedException(
-                      "Authentication credentials are required",
-                      "Missing authentication credentials");
+                    "Authentication credentials are required",
+                    "Missing authentication credentials");
         }
 
         if (auth.startsWith(BASIC_AUTH_PREFIX)) {
@@ -154,7 +154,7 @@ public class AuthenticationFilter implements ContainerRequestFilter {
             String[] values = auth.split(":");
             if (values.length != 2) {
                 throw new BadRequestException(
-                          "Invalid syntax for username and password");
+                        "Invalid syntax for username and password");
             }
 
             final String username = values[0];
@@ -163,7 +163,7 @@ public class AuthenticationFilter implements ContainerRequestFilter {
             if (StringUtils.isEmpty(username) ||
                 StringUtils.isEmpty(password)) {
                 throw new BadRequestException(
-                          "Invalid syntax for username and password");
+                        "Invalid syntax for username and password");
             }
 
             credentials.put(HugeAuthenticator.KEY_USERNAME, username);
@@ -173,7 +173,7 @@ public class AuthenticationFilter implements ContainerRequestFilter {
             credentials.put(HugeAuthenticator.KEY_TOKEN, token);
         } else {
             throw new BadRequestException(
-                      "Only HTTP Basic or Bearer authentication is supported");
+                    "Only HTTP Basic or Bearer authentication is supported");
         }
 
         credentials.put(HugeAuthenticator.KEY_ADDRESS, peer);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/CompressInterceptor.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/CompressInterceptor.java
index a5cf78aa4..f38ffd78f 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/CompressInterceptor.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/CompressInterceptor.java
@@ -24,18 +24,17 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.zip.GZIPOutputStream;
 
+import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import jakarta.inject.Singleton;
 import jakarta.ws.rs.NameBinding;
 import jakarta.ws.rs.WebApplicationException;
 import jakarta.ws.rs.core.MultivaluedMap;
 import jakarta.ws.rs.ext.Provider;
 import jakarta.ws.rs.ext.WriterInterceptor;
 import jakarta.ws.rs.ext.WriterInterceptorContext;
-import jakarta.inject.Singleton;
-
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
-import org.apache.hugegraph.util.Log;
 
 @Provider
 @Singleton
@@ -51,7 +50,7 @@ public class CompressInterceptor implements WriterInterceptor {
 
     @Override
     public void aroundWriteTo(WriterInterceptorContext context)
-                              throws IOException, WebApplicationException {
+            throws IOException, WebApplicationException {
         // If there is no annotation(like exception), we don't compress it
         if (context.getAnnotations().length > 0) {
             try {
@@ -70,14 +69,14 @@ public class CompressInterceptor implements WriterInterceptor {
     }
 
     private void compress(WriterInterceptorContext context)
-                          throws IOException {
+            throws IOException {
         // Get compress info from the @Compress annotation
         final Compress compression = getCompressAnnotation(context);
         final String encoding = compression.value();
         final int buffer = compression.buffer();
 
         // Update header
-        MultivaluedMap<String,Object> headers = context.getHeaders();
+        MultivaluedMap<String, Object> headers = context.getHeaders();
         headers.remove("Content-Length");
         headers.add("Content-Encoding", encoding);
 
@@ -104,7 +103,9 @@ public class CompressInterceptor implements WriterInterceptor {
     @NameBinding
     @Retention(RetentionPolicy.RUNTIME)
     public @interface Compress {
+
         String value() default GZIP;
+
         int buffer() default BUFFER_SIZE;
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/DecompressInterceptor.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/DecompressInterceptor.java
index d8de56090..af8615a4c 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/DecompressInterceptor.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/DecompressInterceptor.java
@@ -37,7 +37,7 @@ public class DecompressInterceptor implements ReaderInterceptor {
 
     @Override
     public Object aroundReadFrom(ReaderInterceptorContext context)
-                                 throws IOException {
+            throws IOException {
         // NOTE: Currently we just support GZIP
         String encoding = context.getHeaders().getFirst("Content-Encoding");
         if (!GZIP.equalsIgnoreCase(encoding)) {
@@ -51,6 +51,7 @@ public class DecompressInterceptor implements ReaderInterceptor {
     @NameBinding
     @Retention(RetentionPolicy.RUNTIME)
     public @interface Decompress {
+
         String value() default GZIP;
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/ExceptionFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/ExceptionFilter.java
index 894f38c66..ded04b354 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/ExceptionFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/ExceptionFilter.java
@@ -25,6 +25,18 @@ import javax.json.Json;
 import javax.json.JsonArrayBuilder;
 import javax.json.JsonObjectBuilder;
 
+import org.apache.commons.lang3.StringUtils;
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.exception.HugeGremlinException;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.glassfish.hk2.api.MultiException;
+
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.ImmutableMap;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.security.RolesAllowed;
 import jakarta.inject.Singleton;
@@ -41,18 +53,6 @@ import jakarta.ws.rs.core.Response;
 import jakarta.ws.rs.ext.ExceptionMapper;
 import jakarta.ws.rs.ext.Provider;
 
-import org.apache.commons.lang3.StringUtils;
-import org.apache.hugegraph.config.ServerOptions;
-import org.glassfish.hk2.api.MultiException;
-
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.exception.HugeGremlinException;
-import org.apache.hugegraph.exception.NotFoundException;
-import com.codahale.metrics.annotation.Timed;
-import com.google.common.collect.ImmutableMap;
-
 public class ExceptionFilter {
 
     private static final int BAD_REQUEST_ERROR =
@@ -107,8 +107,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class HugeExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<HugeException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<HugeException> {
 
         @Override
         public Response toResponse(HugeException exception) {
@@ -121,8 +121,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class IllegalArgumentExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<IllegalArgumentException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<IllegalArgumentException> {
 
         @Override
         public Response toResponse(IllegalArgumentException exception) {
@@ -135,8 +135,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class NotFoundExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<NotFoundException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<NotFoundException> {
 
         @Override
         public Response toResponse(NotFoundException exception) {
@@ -149,8 +149,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class NoSuchElementExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<NoSuchElementException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<NoSuchElementException> {
 
         @Override
         public Response toResponse(NoSuchElementException exception) {
@@ -163,8 +163,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class WebApplicationExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<WebApplicationException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<WebApplicationException> {
 
         @Override
         public Response toResponse(WebApplicationException exception) {
@@ -189,8 +189,8 @@ public class ExceptionFilter {
 
     @Provider
     public static class HugeGremlinExceptionMapper
-                  extends TracedExceptionMapper
-                  implements ExceptionMapper<HugeGremlinException> {
+            extends TracedExceptionMapper
+            implements ExceptionMapper<HugeGremlinException> {
 
         @Override
         public Response toResponse(HugeGremlinException exception) {
@@ -204,7 +204,7 @@ public class ExceptionFilter {
 
     @Provider
     public static class AssertionErrorMapper extends TracedExceptionMapper
-                  implements ExceptionMapper<AssertionError> {
+            implements ExceptionMapper<AssertionError> {
 
         @Override
         public Response toResponse(AssertionError exception) {
@@ -217,7 +217,7 @@ public class ExceptionFilter {
 
     @Provider
     public static class UnknownExceptionMapper extends TracedExceptionMapper
-                  implements ExceptionMapper<Throwable> {
+            implements ExceptionMapper<Throwable> {
 
         @Override
         public Response toResponse(Throwable exception) {
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadDetectFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadDetectFilter.java
index 42344e613..7bda2b756 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadDetectFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadDetectFilter.java
@@ -20,6 +20,15 @@ package org.apache.hugegraph.api.filter;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.define.WorkLoad;
+import org.apache.hugegraph.util.Bytes;
+import org.apache.hugegraph.util.E;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.util.concurrent.RateLimiter;
+
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.ServiceUnavailableException;
 import jakarta.ws.rs.container.ContainerRequestContext;
@@ -29,14 +38,6 @@ import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.PathSegment;
 import jakarta.ws.rs.ext.Provider;
 
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.config.ServerOptions;
-import org.apache.hugegraph.define.WorkLoad;
-import org.apache.hugegraph.util.Bytes;
-import org.apache.hugegraph.util.E;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.util.concurrent.RateLimiter;
-
 @Provider
 @Singleton
 @PreMatching
@@ -51,7 +52,7 @@ public class LoadDetectFilter implements ContainerRequestFilter {
 
     // Call gc every 30+ seconds if memory is low and request frequently
     private static final RateLimiter GC_RATE_LIMITER =
-                         RateLimiter.create(1.0 / 30);
+            RateLimiter.create(1.0 / 30);
 
     @Context
     private jakarta.inject.Provider<HugeConfig> configProvider;
@@ -71,9 +72,9 @@ public class LoadDetectFilter implements ContainerRequestFilter {
         // There will be a thread doesn't work, dedicated to statistics
         if (load.incrementAndGet() >= maxWorkerThreads) {
             throw new ServiceUnavailableException(String.format(
-                      "The server is too busy to process the request, " +
-                      "you can config %s to adjust it or try again later",
-                      ServerOptions.MAX_WORKER_THREADS.name()));
+                    "The server is too busy to process the request, " +
+                    "you can config %s to adjust it or try again later",
+                    ServerOptions.MAX_WORKER_THREADS.name()));
         }
 
         long minFreeMemory = config.get(ServerOptions.MIN_FREE_MEMORY);
@@ -84,11 +85,11 @@ public class LoadDetectFilter implements ContainerRequestFilter {
         if (presumableFreeMem < minFreeMemory) {
             gcIfNeeded();
             throw new ServiceUnavailableException(String.format(
-                      "The server available memory %s(MB) is below than " +
-                      "threshold %s(MB) and can't process the request, " +
-                      "you can config %s to adjust it or try again later",
-                      presumableFreeMem, minFreeMemory,
-                      ServerOptions.MIN_FREE_MEMORY.name()));
+                    "The server available memory %s(MB) is below than " +
+                    "threshold %s(MB) and can't process the request, " +
+                    "you can config %s to adjust it or try again later",
+                    presumableFreeMem, minFreeMemory,
+                    ServerOptions.MIN_FREE_MEMORY.name()));
         }
     }
 
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadReleaseFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadReleaseFilter.java
index 04f2fada5..83a6b0d73 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadReleaseFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/LoadReleaseFilter.java
@@ -17,6 +17,8 @@
 
 package org.apache.hugegraph.api.filter;
 
+import org.apache.hugegraph.define.WorkLoad;
+
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.container.ContainerRequestContext;
 import jakarta.ws.rs.container.ContainerResponseContext;
@@ -24,8 +26,6 @@ import jakarta.ws.rs.container.ContainerResponseFilter;
 import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.ext.Provider;
 
-import org.apache.hugegraph.define.WorkLoad;
-
 @Provider
 @Singleton
 public class LoadReleaseFilter implements ContainerResponseFilter {
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/RedirectFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/RedirectFilter.java
index 35dc3793d..2a2a9142e 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/RedirectFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/RedirectFilter.java
@@ -151,5 +151,6 @@ public class RedirectFilter implements ContainerRequestFilter {
     @NameBinding
     @Retention(RetentionPolicy.RUNTIME)
     public @interface RedirectMasterRole {
+
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/StatusFilter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/StatusFilter.java
index 70f6cb16d..980c714d3 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/StatusFilter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/StatusFilter.java
@@ -34,7 +34,7 @@ public class StatusFilter implements ContainerResponseFilter {
     @Override
     public void filter(ContainerRequestContext requestContext,
                        ContainerResponseContext responseContext)
-                       throws IOException {
+            throws IOException {
         if (responseContext.getStatus() == 200) {
             for (Annotation i : responseContext.getEntityAnnotations()) {
                 if (i instanceof Status) {
@@ -48,6 +48,7 @@ public class StatusFilter implements ContainerResponseFilter {
     @NameBinding
     @Retention(RetentionPolicy.RUNTIME)
     public @interface Status {
+
         int OK = 200;
         int CREATED = 201;
         int ACCEPTED = 202;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/BatchAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/BatchAPI.java
index c533a7d99..2ba95e5bc 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/BatchAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/BatchAPI.java
@@ -21,21 +21,21 @@ import java.util.Map;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.apache.tinkerpop.gremlin.structure.Element;
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.config.ServerOptions;
 import org.apache.hugegraph.define.Checkable;
 import org.apache.hugegraph.define.UpdateStrategy;
 import org.apache.hugegraph.metrics.MetricsUtil;
 import org.apache.hugegraph.server.RestServer;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Element;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.Meter;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -49,14 +49,13 @@ public class BatchAPI extends API {
 
     static {
         MetricsUtil.registerGauge(RestServer.class, "batch-write-threads",
-                                  () -> BATCH_WRITE_THREADS.intValue());
+                                  BATCH_WRITE_THREADS::intValue);
     }
 
     private final Meter batchMeter;
 
     public BatchAPI() {
-        this.batchMeter = MetricsUtil.registerMeter(this.getClass(),
-                                                    "batch-commit");
+        this.batchMeter = MetricsUtil.registerMeter(this.getClass(), "batch-commit");
     }
 
     public <R> R commit(HugeConfig config, HugeGraph g, int size,
@@ -99,8 +98,7 @@ public class BatchAPI extends API {
         protected abstract Object[] properties();
     }
 
-    protected void updateExistElement(JsonElement oldElement,
-                                      JsonElement newElement,
+    protected void updateExistElement(JsonElement oldElement, JsonElement newElement,
                                       Map<String, UpdateStrategy> strategies) {
         if (oldElement == null) {
             return;
@@ -113,8 +111,8 @@ public class BatchAPI extends API {
             if (oldElement.properties.get(key) != null &&
                 newElement.properties.get(key) != null) {
                 Object value = updateStrategy.checkAndUpdateProperty(
-                               oldElement.properties.get(key),
-                               newElement.properties.get(key));
+                        oldElement.properties.get(key),
+                        newElement.properties.get(key));
                 newElement.properties.put(key, value);
             } else if (oldElement.properties.get(key) != null &&
                        newElement.properties.get(key) == null) {
@@ -124,9 +122,7 @@ public class BatchAPI extends API {
         }
     }
 
-    protected void updateExistElement(HugeGraph g,
-                                      Element oldElement,
-                                      JsonElement newElement,
+    protected void updateExistElement(HugeGraph g, Element oldElement, JsonElement newElement,
                                       Map<String, UpdateStrategy> strategies) {
         if (oldElement == null) {
             return;
@@ -139,8 +135,8 @@ public class BatchAPI extends API {
             if (oldElement.property(key).isPresent() &&
                 newElement.properties.get(key) != null) {
                 Object value = updateStrategy.checkAndUpdateProperty(
-                               oldElement.property(key).value(),
-                               newElement.properties.get(key));
+                        oldElement.property(key).value(),
+                        newElement.properties.get(key));
                 value = g.propertyKey(key).validValueOrThrow(value);
                 newElement.properties.put(key, value);
             } else if (oldElement.property(key).isPresent() &&
@@ -151,8 +147,7 @@ public class BatchAPI extends API {
         }
     }
 
-    protected static void updateProperties(HugeElement element,
-                                           JsonElement jsonElement,
+    protected static void updateProperties(HugeElement element, JsonElement jsonElement,
                                            boolean append) {
         for (Map.Entry<String, Object> e : jsonElement.properties.entrySet()) {
             String key = e.getKey();
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/EdgeAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/EdgeAPI.java
index c0a8577e5..25e8cacf0 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/EdgeAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/EdgeAPI.java
@@ -24,31 +24,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.annotation.security.RolesAllowed;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DELETE;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.PUT;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.structure.Direction;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.util.function.TriFunction;
-import org.apache.hugegraph.config.ServerOptions;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.UpdateStrategy;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
@@ -58,6 +33,9 @@ import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.UpdateStrategy;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.PropertyKey;
@@ -69,9 +47,31 @@ import org.apache.hugegraph.traversal.optimize.TraversalUtil;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.structure.Direction;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.util.function.TriFunction;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.annotation.security.RolesAllowed;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/graph/edges")
 @Singleton
 @Tag(name = "EdgeAPI")
@@ -98,18 +98,15 @@ public class EdgeAPI extends BatchAPI {
              * NOTE: If the vertex id is correct but label not match with id,
              * we allow to create it here
              */
-            vertexLabel(g, jsonEdge.sourceLabel,
-                        "Invalid source vertex label '%s'");
-            vertexLabel(g, jsonEdge.targetLabel,
-                        "Invalid target vertex label '%s'");
+            vertexLabel(g, jsonEdge.sourceLabel, "Invalid source vertex label '%s'");
+            vertexLabel(g, jsonEdge.targetLabel, "Invalid target vertex label '%s'");
         }
 
         Vertex srcVertex = getVertex(g, jsonEdge.source, jsonEdge.sourceLabel);
         Vertex tgtVertex = getVertex(g, jsonEdge.target, jsonEdge.targetLabel);
 
         Edge edge = commit(g, () -> {
-            return srcVertex.addEdge(jsonEdge.label, tgtVertex,
-                                     jsonEdge.properties());
+            return srcVertex.addEdge(jsonEdge.label, tgtVertex, jsonEdge.properties());
         });
 
         return manager.serializer(g).writeEdge(edge);
@@ -136,7 +133,7 @@ public class EdgeAPI extends BatchAPI {
         HugeGraph g = graph(manager, graph);
 
         TriFunction<HugeGraph, Object, String, Vertex> getVertex =
-                    checkVertex ? EdgeAPI::getVertex : EdgeAPI::newVertex;
+                checkVertex ? EdgeAPI::getVertex : EdgeAPI::newVertex;
 
         return this.commit(config, g, jsonEdges.size(), () -> {
             List<Id> ids = new ArrayList<>(jsonEdges.size());
@@ -146,12 +143,9 @@ public class EdgeAPI extends BatchAPI {
                  * then the label is correct and not matched id,
                  * it will be allowed currently
                  */
-                Vertex srcVertex = getVertex.apply(g, jsonEdge.source,
-                                                   jsonEdge.sourceLabel);
-                Vertex tgtVertex = getVertex.apply(g, jsonEdge.target,
-                                                   jsonEdge.targetLabel);
-                Edge edge = srcVertex.addEdge(jsonEdge.label, tgtVertex,
-                                              jsonEdge.properties());
+                Vertex srcVertex = getVertex.apply(g, jsonEdge.source, jsonEdge.sourceLabel);
+                Vertex tgtVertex = getVertex.apply(g, jsonEdge.target, jsonEdge.targetLabel);
+                Edge edge = srcVertex.addEdge(jsonEdge.label, tgtVertex, jsonEdge.properties());
                 ids.add((Id) edge.id());
             }
             return manager.serializer(g).writeIds(ids);
@@ -179,16 +173,16 @@ public class EdgeAPI extends BatchAPI {
 
         HugeGraph g = graph(manager, graph);
         Map<Id, JsonEdge> map = new HashMap<>(req.jsonEdges.size());
-        TriFunction<HugeGraph, Object, String, Vertex> getVertex =
-                    req.checkVertex ? EdgeAPI::getVertex : EdgeAPI::newVertex;
+        TriFunction<HugeGraph, Object, String, Vertex> getVertex = req.checkVertex ?
+                                                                   EdgeAPI::getVertex :
+                                                                   EdgeAPI::newVertex;
 
-        return this.commit(config, g, map.size(), () -> {
+        return this.commit(config, g, 0, () -> {
             // 1.Put all newEdges' properties into map (combine first)
             req.jsonEdges.forEach(newEdge -> {
                 Id newEdgeId = getEdgeId(graph(manager, graph), newEdge);
                 JsonEdge oldEdge = map.get(newEdgeId);
-                this.updateExistElement(oldEdge, newEdge,
-                                        req.updateStrategies);
+                this.updateExistElement(oldEdge, newEdge, req.updateStrategies);
                 map.put(newEdgeId, newEdge);
             });
 
@@ -197,19 +191,15 @@ public class EdgeAPI extends BatchAPI {
             Iterator<Edge> oldEdges = g.edges(ids);
             oldEdges.forEachRemaining(oldEdge -> {
                 JsonEdge newEdge = map.get(oldEdge.id());
-                this.updateExistElement(g, oldEdge, newEdge,
-                                        req.updateStrategies);
+                this.updateExistElement(g, oldEdge, newEdge, req.updateStrategies);
             });
 
             // 3.Add all finalEdges
             List<Edge> edges = new ArrayList<>(map.size());
             map.values().forEach(finalEdge -> {
-                Vertex srcVertex = getVertex.apply(g, finalEdge.source,
-                                                   finalEdge.sourceLabel);
-                Vertex tgtVertex = getVertex.apply(g, finalEdge.target,
-                                                   finalEdge.targetLabel);
-                edges.add(srcVertex.addEdge(finalEdge.label, tgtVertex,
-                                            finalEdge.properties()));
+                Vertex srcVertex = getVertex.apply(g, finalEdge.source, finalEdge.sourceLabel);
+                Vertex tgtVertex = getVertex.apply(g, finalEdge.target, finalEdge.targetLabel);
+                edges.add(srcVertex.addEdge(finalEdge.label, tgtVertex, finalEdge.properties()));
             });
 
             // If return ids, the ids.size() maybe different with the origins'
@@ -253,7 +243,6 @@ public class EdgeAPI extends BatchAPI {
         }
 
         commit(g, () -> updateProperties(edge, jsonEdge, append));
-
         return manager.serializer(g).writeEdge(edge);
     }
 
@@ -281,8 +270,7 @@ public class EdgeAPI extends BatchAPI {
         Map<String, Object> props = parseProperties(properties);
         if (page != null) {
             E.checkArgument(offset == 0,
-                            "Not support querying edges based on paging " +
-                            "and offset together");
+                            "Not support querying edges based on paging and offset together");
         }
 
         Id vertex = VertexAPI.checkAndParseVertexId(vertexId);
@@ -321,8 +309,7 @@ public class EdgeAPI extends BatchAPI {
         if (page == null) {
             traversal = traversal.range(offset, offset + limit);
         } else {
-            traversal = traversal.has(QueryHolder.SYSPROP_PAGE, page)
-                                 .limit(limit);
+            traversal = traversal.has(QueryHolder.SYSPROP_PAGE, page).limit(limit);
         }
 
         try {
@@ -372,42 +359,38 @@ public class EdgeAPI extends BatchAPI {
                 g.removeEdge(label, id);
             } catch (NotFoundException e) {
                 throw new IllegalArgumentException(String.format(
-                          "No such edge with id: '%s', %s", id, e));
+                        "No such edge with id: '%s', %s", id, e));
             } catch (NoSuchElementException e) {
                 throw new IllegalArgumentException(String.format(
-                          "No such edge with id: '%s'", id));
+                        "No such edge with id: '%s'", id));
             }
         });
     }
 
-    private static void checkBatchSize(HugeConfig config,
-                                       List<JsonEdge> edges) {
+    private static void checkBatchSize(HugeConfig config, List<JsonEdge> edges) {
         int max = config.get(ServerOptions.MAX_EDGES_PER_BATCH);
         if (edges.size() > max) {
             throw new IllegalArgumentException(String.format(
-                      "Too many edges for one time post, " +
-                      "the maximum number is '%s'", max));
+                    "Too many edges for one time post, " +
+                    "the maximum number is '%s'", max));
         }
-        if (edges.size() == 0) {
-            throw new IllegalArgumentException(
-                      "The number of edges can't be 0");
+        if (edges.isEmpty()) {
+            throw new IllegalArgumentException("The number of edges can't be 0");
         }
     }
 
-    private static Vertex getVertex(HugeGraph graph,
-                                    Object id, String label) {
+    private static Vertex getVertex(HugeGraph graph, Object id, String label) {
         HugeVertex vertex;
         try {
             vertex = (HugeVertex) graph.vertices(id).next();
         } catch (NoSuchElementException e) {
-            throw new IllegalArgumentException(String.format(
-                      "Invalid vertex id '%s'", id));
+            throw new IllegalArgumentException(String.format("Invalid vertex id '%s'", id));
         }
         if (label != null && !vertex.label().equals(label)) {
             throw new IllegalArgumentException(String.format(
-                      "The label of vertex '%s' is unmatched, users expect " +
-                      "label '%s', actual label stored is '%s'",
-                      id, label, vertex.label()));
+                    "The label of vertex '%s' is unmatched, users expect " +
+                    "label '%s', actual label stored is '%s'",
+                    id, label, vertex.label()));
         }
         // Clone a new vertex to support multi-thread access
         return vertex.copy();
@@ -419,8 +402,7 @@ public class EdgeAPI extends BatchAPI {
         return new HugeVertex(g, idValue, vl);
     }
 
-    private static VertexLabel vertexLabel(HugeGraph graph, String label,
-                                           String message) {
+    private static VertexLabel vertexLabel(HugeGraph graph, String label, String message) {
         try {
             // NOTE: don't use SchemaManager because it will throw 404
             return graph.vertexLabel(label);
@@ -437,8 +419,8 @@ public class EdgeAPI extends BatchAPI {
             return Direction.valueOf(direction);
         } catch (Exception e) {
             throw new IllegalArgumentException(String.format(
-                      "Direction value must be in [OUT, IN, BOTH], " +
-                      "but got '%s'", direction));
+                    "Direction value must be in [OUT, IN, BOTH], " +
+                    "but got '%s'", direction));
         }
     }
 
@@ -453,8 +435,7 @@ public class EdgeAPI extends BatchAPI {
                 String sortKey = pk.name();
                 Object sortKeyValue = newEdge.properties.get(sortKey);
                 E.checkArgument(sortKeyValue != null,
-                                "The value of sort key '%s' can't be null",
-                                sortKey);
+                                "The value of sort key '%s' can't be null", sortKey);
                 sortKeyValue = pk.validValueOrThrow(sortKeyValue);
                 sortKeyValues.add(sortKeyValue);
             });
@@ -487,14 +468,11 @@ public class EdgeAPI extends BatchAPI {
 
         private static void checkUpdate(BatchEdgeRequest req) {
             E.checkArgumentNotNull(req, "BatchEdgeRequest can't be null");
-            E.checkArgumentNotNull(req.jsonEdges,
-                                   "Parameter 'edges' can't be null");
-            E.checkArgument(req.updateStrategies != null &&
-                            !req.updateStrategies.isEmpty(),
+            E.checkArgumentNotNull(req.jsonEdges, "Parameter 'edges' can't be null");
+            E.checkArgument(req.updateStrategies != null && !req.updateStrategies.isEmpty(),
                             "Parameter 'update_strategies' can't be empty");
-            E.checkArgument(req.createIfNotExist == true,
-                            "Parameter 'create_if_not_exist' " +
-                            "dose not support false now");
+            E.checkArgument(req.createIfNotExist,
+                            "Parameter 'create_if_not_exist' dose not support false now");
         }
 
         @Override
@@ -524,15 +502,11 @@ public class EdgeAPI extends BatchAPI {
             E.checkArgumentNotNull(this.source, "Expect source vertex id");
             E.checkArgumentNotNull(this.target, "Expect target vertex id");
             if (isBatch) {
-                E.checkArgumentNotNull(this.sourceLabel,
-                                       "Expect source vertex label");
-                E.checkArgumentNotNull(this.targetLabel,
-                                       "Expect target vertex label");
+                E.checkArgumentNotNull(this.sourceLabel, "Expect source vertex label");
+                E.checkArgumentNotNull(this.targetLabel, "Expect target vertex label");
             } else {
-                E.checkArgument(this.sourceLabel == null &&
-                                this.targetLabel == null ||
-                                this.sourceLabel != null &&
-                                this.targetLabel != null,
+                E.checkArgument(this.sourceLabel == null && this.targetLabel == null ||
+                                this.sourceLabel != null && this.targetLabel != null,
                                 "The both source and target vertex label " +
                                 "are either passed in, or not passed in");
             }
@@ -541,15 +515,13 @@ public class EdgeAPI extends BatchAPI {
 
         @Override
         public void checkUpdate() {
-            E.checkArgumentNotNull(this.properties,
-                                   "The properties of edge can't be null");
+            E.checkArgumentNotNull(this.properties, "The properties of edge can't be null");
 
             for (Map.Entry<String, Object> entry : this.properties.entrySet()) {
                 String key = entry.getKey();
                 Object value = entry.getValue();
                 E.checkArgumentNotNull(value, "Not allowed to set value of " +
-                                       "property '%s' to null for edge '%s'",
-                                       key, this.id);
+                                              "property '%s' to null for edge '%s'", key, this.id);
             }
         }
 
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/VertexAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/VertexAPI.java
index 98032d2ad..e25e7888b 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/VertexAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/graph/VertexAPI.java
@@ -25,29 +25,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.annotation.security.RolesAllowed;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DELETE;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.PUT;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.hugegraph.config.ServerOptions;
-import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.define.UpdateStrategy;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
@@ -57,6 +34,9 @@ import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.SplicingIdGenerator;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.define.UpdateStrategy;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
@@ -68,9 +48,29 @@ import org.apache.hugegraph.type.define.IdStrategy;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.annotation.security.RolesAllowed;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/graph/vertices")
 @Singleton
 @Tag(name = "VertexAPI")
@@ -148,7 +148,7 @@ public class VertexAPI extends BatchAPI {
         HugeGraph g = graph(manager, graph);
         Map<Id, JsonVertex> map = new HashMap<>(req.jsonVertices.size());
 
-        return this.commit(config, g, map.size(), () -> {
+        return this.commit(config, g, 0, () -> {
             /*
              * 1.Put all newVertices' properties into map (combine first)
              * - Consider primary-key & user-define ID mode first
@@ -156,8 +156,7 @@ public class VertexAPI extends BatchAPI {
             req.jsonVertices.forEach(newVertex -> {
                 Id newVertexId = getVertexId(g, newVertex);
                 JsonVertex oldVertex = map.get(newVertexId);
-                this.updateExistElement(oldVertex, newVertex,
-                                        req.updateStrategies);
+                this.updateExistElement(oldVertex, newVertex, req.updateStrategies);
                 map.put(newVertexId, newVertex);
             });
 
@@ -166,8 +165,7 @@ public class VertexAPI extends BatchAPI {
             Iterator<Vertex> oldVertices = g.vertices(ids);
             oldVertices.forEachRemaining(oldVertex -> {
                 JsonVertex newVertex = map.get(oldVertex.id());
-                this.updateExistElement(g, oldVertex, newVertex,
-                                        req.updateStrategies);
+                this.updateExistElement(g, oldVertex, newVertex, req.updateStrategies);
             });
 
             // 3.Add finalVertices and return them
@@ -177,8 +175,7 @@ public class VertexAPI extends BatchAPI {
             });
 
             // If return ids, the ids.size() maybe different with the origins'
-            return manager.serializer(g)
-                          .writeVertices(vertices.iterator(), false);
+            return manager.serializer(g).writeVertices(vertices.iterator(), false);
         });
     }
 
@@ -238,8 +235,7 @@ public class VertexAPI extends BatchAPI {
         Map<String, Object> props = parseProperties(properties);
         if (page != null) {
             E.checkArgument(offset == 0,
-                            "Not support querying vertices based on paging " +
-                            "and offset together");
+                            "Not support querying vertices based on paging and offset together");
         }
 
         HugeGraph g = graph(manager, graph);
@@ -265,13 +261,11 @@ public class VertexAPI extends BatchAPI {
         if (page == null) {
             traversal = traversal.range(offset, offset + limit);
         } else {
-            traversal = traversal.has(QueryHolder.SYSPROP_PAGE, page)
-                                 .limit(limit);
+            traversal = traversal.has(QueryHolder.SYSPROP_PAGE, page).limit(limit);
         }
 
         try {
-            return manager.serializer(g).writeVertices(traversal,
-                                                       page != null);
+            return manager.serializer(g).writeVertices(traversal, page != null);
         } finally {
             if (g.tx().isOpen()) {
                 g.tx().close();
@@ -319,10 +313,10 @@ public class VertexAPI extends BatchAPI {
                 g.removeVertex(label, id);
             } catch (NotFoundException e) {
                 throw new IllegalArgumentException(String.format(
-                          "No such vertex with id: '%s', %s", id, e));
+                        "No such vertex with id: '%s', %s", id, e));
             } catch (NoSuchElementException e) {
                 throw new IllegalArgumentException(String.format(
-                          "No such vertex with id: '%s'", id));
+                        "No such vertex with id: '%s'", id));
             }
         });
     }
@@ -340,22 +334,19 @@ public class VertexAPI extends BatchAPI {
             return uuid ? Text.uuid((String) id) : HugeVertex.getIdValue(id);
         } catch (Exception e) {
             throw new IllegalArgumentException(String.format(
-                      "The vertex id must be formatted as Number/String/UUID" +
-                      ", but got '%s'", idValue));
+                    "The vertex id must be formatted as Number/String/UUID" +
+                    ", but got '%s'", idValue));
         }
     }
 
-    private static void checkBatchSize(HugeConfig config,
-                                       List<JsonVertex> vertices) {
+    private static void checkBatchSize(HugeConfig config, List<JsonVertex> vertices) {
         int max = config.get(ServerOptions.MAX_VERTICES_PER_BATCH);
         if (vertices.size() > max) {
             throw new IllegalArgumentException(String.format(
-                      "Too many vertices for one time post, " +
-                      "the maximum number is '%s'", max));
+                    "Too many vertices for one time post, the maximum number is '%s'", max));
         }
-        if (vertices.size() == 0) {
-            throw new IllegalArgumentException(
-                      "The number of vertices can't be 0");
+        if (vertices.isEmpty()) {
+            throw new IllegalArgumentException("The number of vertices can't be 0");
         }
     }
 
@@ -373,8 +364,7 @@ public class VertexAPI extends BatchAPI {
                 String propertyKey = g.propertyKey(pkId).name();
                 Object propertyValue = vertex.properties.get(propertyKey);
                 E.checkArgument(propertyValue != null,
-                                "The value of primary key '%s' can't be null",
-                                propertyKey);
+                                "The value of primary key '%s' can't be null", propertyKey);
                 pkValues.add(propertyValue);
             }
 
@@ -402,8 +392,7 @@ public class VertexAPI extends BatchAPI {
             E.checkArgumentNotNull(req, "BatchVertexRequest can't be null");
             E.checkArgumentNotNull(req.jsonVertices,
                                    "Parameter 'vertices' can't be null");
-            E.checkArgument(req.updateStrategies != null &&
-                            !req.updateStrategies.isEmpty(),
+            E.checkArgument(req.updateStrategies != null && !req.updateStrategies.isEmpty(),
                             "Parameter 'update_strategies' can't be empty");
             E.checkArgument(req.createIfNotExist,
                             "Parameter 'create_if_not_exist' " +
@@ -428,14 +417,13 @@ public class VertexAPI extends BatchAPI {
 
         @Override
         public void checkUpdate() {
-            E.checkArgumentNotNull(this.properties,
-                                   "The properties of vertex can't be null");
+            E.checkArgumentNotNull(this.properties, "The properties of vertex can't be null");
 
             for (Map.Entry<String, Object> e : this.properties.entrySet()) {
                 String key = e.getKey();
                 Object value = e.getValue();
                 E.checkArgumentNotNull(value, "Not allowed to set value of " +
-                                       "property '%s' to null for vertex '%s'",
+                                              "property '%s' to null for vertex '%s'",
                                        key, this.id);
             }
         }
@@ -462,7 +450,7 @@ public class VertexAPI extends BatchAPI {
             }
             if (this.id != null) {
                 newProps[appendIndex++] = T.id;
-                // Keep value++ to avoid code trap
+                // Note: Here we keep value++ to avoid code trap
                 newProps[appendIndex++] = this.id;
             }
             return newProps;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/AbstractJerseyRestClient.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/AbstractJerseyRestClient.java
index 37963a371..810dbc8b4 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/AbstractJerseyRestClient.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/AbstractJerseyRestClient.java
@@ -83,7 +83,7 @@ public abstract class AbstractJerseyRestClient {
          * repository seems to have a bug: https://github.com/jersey/jersey/pull/3752
          */
         PoolingHttpClientConnectionManager pool =
-            new PoolingHttpClientConnectionManager(TTL, TimeUnit.HOURS);
+                new PoolingHttpClientConnectionManager(TTL, TimeUnit.HOURS);
         Integer maxTotal = (Integer) conf.getProperty(PROPERTY_MAX_TOTAL);
         Integer maxPerRoute = (Integer) conf.getProperty(PROPERTY_MAX_PER_ROUTE);
 
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinAPI.java
index 09459ca4c..4373b0f00 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinAPI.java
@@ -17,7 +17,15 @@
 
 package org.apache.hugegraph.api.gremlin;
 
+import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.metrics.MetricsUtil;
+
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.annotation.Timed;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.POST;
@@ -29,14 +37,6 @@ import jakarta.ws.rs.core.MultivaluedMap;
 import jakarta.ws.rs.core.Response;
 import jakarta.ws.rs.core.UriInfo;
 
-import org.apache.hugegraph.api.filter.CompressInterceptor.Compress;
-import org.apache.hugegraph.api.filter.RedirectFilter;
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.metrics.MetricsUtil;
-import com.codahale.metrics.Histogram;
-import com.codahale.metrics.annotation.Timed;
-import jakarta.inject.Singleton;
-
 @Path("gremlin")
 @Singleton
 @Tag(name = "GremlinAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinQueryAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinQueryAPI.java
index 009f44dbd..ad4a6452b 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinQueryAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/gremlin/GremlinQueryAPI.java
@@ -24,6 +24,7 @@ import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.config.ServerOptions;
 import org.apache.hugegraph.exception.HugeGremlinException;
+
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/AlgorithmAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/AlgorithmAPI.java
index 408d27a39..8ebf1f6d1 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/AlgorithmAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/AlgorithmAPI.java
@@ -37,7 +37,6 @@ import com.codahale.metrics.annotation.Timed;
 import com.google.common.collect.ImmutableMap;
 
 import io.swagger.v3.oas.annotations.tags.Tag;
-
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.NotFoundException;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/GremlinAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/GremlinAPI.java
index 5bb8274b7..e7def0506 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/GremlinAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/GremlinAPI.java
@@ -190,11 +190,11 @@ public class GremlinAPI extends API {
             String gremlin = (String) map.get("gremlin");
             @SuppressWarnings("unchecked")
             Map<String, Object> bindings = (Map<String, Object>)
-                                           map.get("bindings");
+                    map.get("bindings");
             String language = (String) map.get("language");
             @SuppressWarnings("unchecked")
             Map<String, String> aliases = (Map<String, String>)
-                                          map.get("aliases");
+                    map.get("aliases");
 
             GremlinRequest request = new GremlinRequest();
             request.gremlin(gremlin);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/TaskAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/TaskAPI.java
index 8daf2954d..d9b90de10 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/TaskAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/job/TaskAPI.java
@@ -92,7 +92,7 @@ public class TaskAPI extends API {
             // Set limit to NO_LIMIT to ignore limit when query task by ids
             limit = NO_LIMIT;
             List<Id> idList = ids.stream().map(IdGenerator::of)
-                                          .collect(Collectors.toList());
+                                 .collect(Collectors.toList());
             iter = scheduler.tasks(idList);
         } else {
             if (status == null) {
@@ -159,7 +159,7 @@ public class TaskAPI extends API {
 
         if (!ACTION_CANCEL.equals(action)) {
             throw new NotSupportedException(String.format(
-                      "Not support action '%s'", action));
+                    "Not support action '%s'", action));
         }
 
         TaskScheduler scheduler = graph(manager, graph).taskScheduler();
@@ -173,8 +173,8 @@ public class TaskAPI extends API {
 
         assert task.completed() || task.cancelling();
         throw new BadRequestException(String.format(
-                  "Can't cancel task '%s' which is completed or cancelling",
-                  id));
+                "Can't cancel task '%s' which is completed or cancelling",
+                id));
     }
 
     private static TaskStatus parseStatus(String status) {
@@ -182,8 +182,8 @@ public class TaskAPI extends API {
             return TaskStatus.valueOf(status.toUpperCase());
         } catch (Exception e) {
             throw new IllegalArgumentException(String.format(
-                      "Status value must be in %s, but got '%s'",
-                      Arrays.asList(TaskStatus.values()), status));
+                    "Status value must be in %s, but got '%s'",
+                    Arrays.asList(TaskStatus.values()), status));
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/metrics/MetricsAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/metrics/MetricsAPI.java
index 605abef1d..4682c35df 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/metrics/MetricsAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/metrics/MetricsAPI.java
@@ -72,7 +72,6 @@ import com.codahale.metrics.annotation.Timed;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
-
 import jakarta.annotation.security.RolesAllowed;
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.GET;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/GraphsAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/GraphsAPI.java
index 8bcc9311d..f45c228ba 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/GraphsAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/GraphsAPI.java
@@ -22,6 +22,23 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
+import org.apache.commons.lang3.StringUtils;
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.auth.HugeAuthenticator.RequiredPerm;
+import org.apache.hugegraph.auth.HugePermission;
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.type.define.GraphMode;
+import org.apache.hugegraph.type.define.GraphReadMode;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.ImmutableMap;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.security.RolesAllowed;
 import jakarta.inject.Singleton;
@@ -30,8 +47,8 @@ import jakarta.ws.rs.DELETE;
 import jakarta.ws.rs.ForbiddenException;
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.NotSupportedException;
-import jakarta.ws.rs.PUT;
 import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.PathParam;
 import jakarta.ws.rs.Produces;
@@ -39,23 +56,6 @@ import jakarta.ws.rs.QueryParam;
 import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.SecurityContext;
 
-import org.apache.commons.lang3.StringUtils;
-import org.apache.hugegraph.core.GraphManager;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.auth.HugeAuthenticator.RequiredPerm;
-import org.apache.hugegraph.auth.HugePermission;
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.type.define.GraphMode;
-import org.apache.hugegraph.type.define.GraphReadMode;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.JsonUtil;
-import org.apache.hugegraph.util.Log;
-import com.codahale.metrics.annotation.Timed;
-import com.google.common.collect.ImmutableMap;
-
 @Path("graphs")
 @Singleton
 @Tag(name = "GraphsAPI")
@@ -154,7 +154,7 @@ public class GraphsAPI extends API {
         File file = config.file();
         if (file == null) {
             throw new NotSupportedException("Can't access the api in " +
-                      "a node which started with non local file config.");
+                                            "a node which started with non local file config.");
         }
         return file;
     }
@@ -255,9 +255,9 @@ public class GraphsAPI extends API {
     @Produces(APPLICATION_JSON_WITH_CHARSET)
     @RolesAllowed("admin")
     public Map<String, GraphReadMode> graphReadMode(
-                                      @Context GraphManager manager,
-                                      @PathParam("name") String name,
-                                      GraphReadMode readMode) {
+            @Context GraphManager manager,
+            @PathParam("name") String name,
+            GraphReadMode readMode) {
         LOG.debug("Set graph-read-mode to: '{}' of graph '{}'",
                   readMode, name);
 
@@ -275,8 +275,8 @@ public class GraphsAPI extends API {
     @Produces(APPLICATION_JSON_WITH_CHARSET)
     @RolesAllowed({"admin", "$owner=$name"})
     public Map<String, GraphReadMode> graphReadMode(
-                                      @Context GraphManager manager,
-                                      @PathParam("name") String name) {
+            @Context GraphManager manager,
+            @PathParam("name") String name) {
         LOG.debug("Get graph-read-mode of graph '{}'", name);
 
         HugeGraph g = graph(manager, name);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/ProfileAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/ProfileAPI.java
index 26a7873e4..279f09556 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/ProfileAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/ProfileAPI.java
@@ -24,31 +24,30 @@ import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.core.Application;
-import jakarta.ws.rs.core.Context;
-import jakarta.ws.rs.core.MediaType;
-
 import org.apache.commons.lang3.StringUtils;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.InsertionOrderUtil;
+import org.apache.hugegraph.util.JsonUtil;
+import org.apache.hugegraph.version.CoreVersion;
 import org.apache.tinkerpop.shaded.jackson.annotation.JsonProperty;
 import org.glassfish.jersey.model.Parameter.Source;
 import org.glassfish.jersey.server.model.Parameter;
 import org.glassfish.jersey.server.model.Resource;
 import org.glassfish.jersey.server.model.ResourceMethod;
 
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.InsertionOrderUtil;
-import org.apache.hugegraph.util.JsonUtil;
-import org.apache.hugegraph.version.CoreVersion;
-
 import com.codahale.metrics.annotation.Timed;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.Application;
+import jakarta.ws.rs.core.Context;
+import jakarta.ws.rs.core.MediaType;
+
 @Path("/")
 @Singleton
 @Tag(name = "ProfileAPI")
@@ -154,8 +153,8 @@ public class ProfileAPI {
             categories = this.apis.computeIfAbsent(category.dir,
                                                    k -> new TreeMap<>());
             List<APIProfile> profiles = categories.computeIfAbsent(
-                                                   category.category,
-                                                   k -> new ArrayList<>());
+                    category.category,
+                    k -> new ArrayList<>());
             profiles.add(profile);
         }
     }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/VersionAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/VersionAPI.java
index b6a095c9e..5f951e7ac 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/VersionAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/VersionAPI.java
@@ -19,6 +19,13 @@ package org.apache.hugegraph.api.profile;
 
 import java.util.Map;
 
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.version.ApiVersion;
+import org.apache.hugegraph.version.CoreVersion;
+
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.ImmutableMap;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.security.PermitAll;
 import jakarta.inject.Singleton;
@@ -26,12 +33,6 @@ import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.Produces;
 
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.version.ApiVersion;
-import org.apache.hugegraph.version.CoreVersion;
-import com.codahale.metrics.annotation.Timed;
-import com.google.common.collect.ImmutableMap;
-
 @Path("versions")
 @Singleton
 @Tag(name = "VersionAPI")
@@ -43,9 +44,9 @@ public class VersionAPI extends API {
     @PermitAll
     public Object list() {
         Map<String, String> versions = ImmutableMap.of("version", "v1",
-                                       "core", CoreVersion.VERSION.toString(),
-                                       "gremlin", CoreVersion.GREMLIN_VERSION,
-                                       "api", ApiVersion.VERSION.toString());
+                                                       "core", CoreVersion.VERSION.toString(),
+                                                       "gremlin", CoreVersion.GREMLIN_VERSION,
+                                                       "api", ApiVersion.VERSION.toString());
         return ImmutableMap.of("versions", versions);
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/WhiteIpListAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/WhiteIpListAPI.java
index f765ff46a..e965ed21a 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/WhiteIpListAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/profile/WhiteIpListAPI.java
@@ -76,7 +76,8 @@ public class WhiteIpListAPI extends API {
     @Produces(APPLICATION_JSON_WITH_CHARSET)
     @RolesAllowed("admin")
     @Operation(summary = "update white ip list")
-    public Map<String, Object> updateWhiteIPs(@Context GraphManager manager, Map<String, Object> actionMap) {
+    public Map<String, Object> updateWhiteIPs(@Context GraphManager manager,
+                                              Map<String, Object> actionMap) {
         E.checkArgument(actionMap != null,
                         "Missing argument: actionMap");
         Set<String> whiteIpList = manager.authManager().listWhiteIPs();
@@ -137,7 +138,8 @@ public class WhiteIpListAPI extends API {
     @Produces(APPLICATION_JSON_WITH_CHARSET)
     @RolesAllowed("admin")
     @Operation(summary = "enable/disable the white ip list")
-    public Map<String, Object> updateStatus(@Context GraphManager manager, @QueryParam("status") String status) {
+    public Map<String, Object> updateStatus(@Context GraphManager manager,
+                                            @QueryParam("status") String status) {
         LOG.debug("Enable or disable white ip list");
         E.checkArgument("true".equals(status) ||
                         "false".equals(status),
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/raft/RaftAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/raft/RaftAPI.java
index 2c2d893b6..76f44a524 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/raft/RaftAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/raft/RaftAPI.java
@@ -21,38 +21,38 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.annotation.security.RolesAllowed;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.Consumes;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
-import org.apache.hugegraph.api.filter.RedirectFilter;
-import org.apache.hugegraph.core.GraphManager;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.api.filter.RedirectFilter;
 import org.apache.hugegraph.api.filter.StatusFilter.Status;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.store.raft.RaftAddPeerJob;
 import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
 import org.apache.hugegraph.backend.store.raft.RaftRemovePeerJob;
+import org.apache.hugegraph.core.GraphManager;
 import org.apache.hugegraph.job.JobBuilder;
 import org.apache.hugegraph.util.DateUtil;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.google.common.collect.ImmutableMap;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.annotation.security.RolesAllowed;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.Consumes;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/raft")
 @Singleton
 @Tag(name = "RaftAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPI.java
index 1154d7144..82ad79e38 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPI.java
@@ -20,16 +20,6 @@ package org.apache.hugegraph.api.traversers;
 import static org.apache.hugegraph.traversal.algorithm.HugeTraverser.DEFAULT_ELEMENTS_LIMIT;
 import static org.apache.hugegraph.traversal.algorithm.HugeTraverser.DEFAULT_MAX_DEGREE;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.graph.EdgeAPI;
@@ -40,9 +30,20 @@ import org.apache.hugegraph.traversal.algorithm.PredictionTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
+
 import com.codahale.metrics.annotation.Timed;
 import com.google.common.collect.ImmutableMap;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 /**
  * AdamicAdar is one of the prediction algorithms in graph, you can get more
  * info and definition in:
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/CountAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/CountAPI.java
index f2e3f0c9a..0855c8cb6 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/CountAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/CountAPI.java
@@ -25,31 +25,31 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.core.Context;
-
-import org.apache.hugegraph.core.GraphManager;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.core.GraphManager;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.traversal.algorithm.CountTraverser;
 import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonAlias;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.collect.ImmutableMap;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/traversers/count")
 @Singleton
 @Tag(name = "CountAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/EdgeExistenceAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/EdgeExistenceAPI.java
index 5237fdcdb..f52c2b57e 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/EdgeExistenceAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/EdgeExistenceAPI.java
@@ -25,7 +25,6 @@ import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.graph.VertexAPI;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.core.GraphManager;
-import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.traversal.algorithm.EdgeExistenceTraverser;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankAPI.java
index 9c1fda3be..d5bf74ee2 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankAPI.java
@@ -26,29 +26,29 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.core.Context;
-
-import org.apache.hugegraph.core.GraphManager;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.core.GraphManager;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.traversal.algorithm.NeighborRankTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonAlias;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/traversers/neighborrank")
 @Singleton
 @Tag(name = "NeighborRankAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankAPI.java
index 8619fb171..aefc9daaa 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankAPI.java
@@ -24,16 +24,6 @@ import static org.apache.hugegraph.traversal.algorithm.HugeTraverser.NO_LIMIT;
 
 import java.util.Map;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.POST;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.core.Context;
-
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.backend.id.Id;
@@ -43,9 +33,19 @@ import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.traversal.algorithm.PersonalRankTraverser;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.codahale.metrics.annotation.Timed;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.Context;
+
 @Path("graphs/{graph}/traversers/personalrank")
 @Singleton
 @Tag(name = "PersonalRankAPI")
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPI.java
index 881138bbf..fb4d73e5a 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPI.java
@@ -20,16 +20,6 @@ package org.apache.hugegraph.api.traversers;
 import static org.apache.hugegraph.traversal.algorithm.HugeTraverser.DEFAULT_ELEMENTS_LIMIT;
 import static org.apache.hugegraph.traversal.algorithm.HugeTraverser.DEFAULT_MAX_DEGREE;
 
-import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.inject.Singleton;
-import jakarta.ws.rs.DefaultValue;
-import jakarta.ws.rs.GET;
-import jakarta.ws.rs.Path;
-import jakarta.ws.rs.PathParam;
-import jakarta.ws.rs.Produces;
-import jakarta.ws.rs.QueryParam;
-import jakarta.ws.rs.core.Context;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.API;
 import org.apache.hugegraph.api.graph.EdgeAPI;
@@ -40,9 +30,20 @@ import org.apache.hugegraph.traversal.algorithm.PredictionTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
+
 import com.codahale.metrics.annotation.Timed;
 import com.google.common.collect.ImmutableMap;
 
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.inject.Singleton;
+import jakarta.ws.rs.DefaultValue;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.QueryParam;
+import jakarta.ws.rs.core.Context;
+
 /**
  * ResourceAllocation is one of the prediction algorithms in graph, you can get
  * more info and definition in:
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/Vertices.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/Vertices.java
index 183c27d87..bf231ca90 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/Vertices.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/traversers/Vertices.java
@@ -23,8 +23,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
@@ -33,6 +31,8 @@ import org.apache.hugegraph.traversal.optimize.TraversalUtil;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 public class Vertices {
@@ -47,8 +47,8 @@ public class Vertices {
     public Iterator<Vertex> vertices(HugeGraph g) {
         Map<String, Object> props = this.properties;
         E.checkArgument(!((this.ids == null || this.ids.isEmpty()) &&
-                        (props == null || props.isEmpty()) &&
-                        this.label == null), "No source vertices provided");
+                          (props == null || props.isEmpty()) &&
+                          this.label == null), "No source vertices provided");
         Iterator<Vertex> iterator;
         if (this.ids != null && !this.ids.isEmpty()) {
             List<Id> sourceIds = new ArrayList<>(this.ids.size());
@@ -72,7 +72,7 @@ public class Vertices {
             assert !query.empty();
             iterator = g.vertices(query);
             E.checkArgument(iterator.hasNext(), "Not exist source vertex " +
-                            "with label '%s' and properties '%s'",
+                                                "with label '%s' and properties '%s'",
                             this.label, props);
         }
         return iterator;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/variables/VariablesAPI.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/variables/VariablesAPI.java
index 89272fb8f..2ea29aaf1 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/variables/VariablesAPI.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/variables/VariablesAPI.java
@@ -20,6 +20,16 @@ package org.apache.hugegraph.api.variables;
 import java.util.Map;
 import java.util.Optional;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.api.API;
+import org.apache.hugegraph.core.GraphManager;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.codahale.metrics.annotation.Timed;
+import com.google.common.collect.ImmutableMap;
+
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.inject.Singleton;
 import jakarta.ws.rs.Consumes;
@@ -32,16 +42,6 @@ import jakarta.ws.rs.PathParam;
 import jakarta.ws.rs.Produces;
 import jakarta.ws.rs.core.Context;
 
-import org.apache.hugegraph.core.GraphManager;
-import org.slf4j.Logger;
-
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.api.API;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
-import com.codahale.metrics.annotation.Timed;
-import com.google.common.collect.ImmutableMap;
-
 @Path("graphs/{graph}/variables")
 @Singleton
 @Tag(name = "VariablesAPI")
@@ -91,7 +91,7 @@ public class VariablesAPI extends API {
         Optional<?> object = g.variables().get(key);
         if (!object.isPresent()) {
             throw new NotFoundException(String.format(
-                      "Variable '%s' does not exist", key));
+                    "Variable '%s' does not exist", key));
         }
         return ImmutableMap.of(key, object.get());
     }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ConfigAuthenticator.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ConfigAuthenticator.java
index 2106d54dc..21cf39682 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ConfigAuthenticator.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ConfigAuthenticator.java
@@ -50,8 +50,9 @@ public class ConfigAuthenticator implements HugeAuthenticator {
 
     /**
      * Verify if a user is legal
-     * @param username  the username for authentication
-     * @param password  the password for authentication
+     *
+     * @param username the username for authentication
+     * @param password the password for authentication
      * @return String No permission if return ROLE_NONE else return a role
      */
     @Override
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ContextGremlinServer.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ContextGremlinServer.java
index f753fc2ca..7f8829974 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ContextGremlinServer.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/ContextGremlinServer.java
@@ -115,8 +115,8 @@ public class ContextGremlinServer extends GremlinServer {
             String gName = G_PREFIX + graph;
             if (manager.getTraversalSource(gName) != null) {
                 throw new HugeException(
-                          "Found existing name '%s' in global bindings, " +
-                          "it may lead to gremlin query error.", gName);
+                        "Found existing name '%s' in global bindings, " +
+                        "it may lead to gremlin query error.", gName);
             }
             // Add a traversal source for all graphs with customed rule.
             manager.putTraversalSource(gName, g);
@@ -136,7 +136,7 @@ public class ContextGremlinServer extends GremlinServer {
         manager.putTraversalSource(G_PREFIX + name, g);
 
         Whitebox.invoke(executor, "globalBindings",
-                        new Class<?>[]{ String.class, Object.class },
+                        new Class<?>[]{String.class, Object.class},
                         "put", name, graph);
     }
 
@@ -149,7 +149,7 @@ public class ContextGremlinServer extends GremlinServer {
             manager.removeGraph(name);
             manager.removeTraversalSource(G_PREFIX + name);
             Whitebox.invoke(executor, "globalBindings",
-                            new Class<?>[]{ Object.class },
+                            new Class<?>[]{Object.class},
                             "remove", name);
         } catch (Exception e) {
             throw new HugeException("Failed to remove graph '%s' from " +
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeAuthenticator.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeAuthenticator.java
index e1077d946..1e6768095 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeAuthenticator.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeAuthenticator.java
@@ -81,7 +81,7 @@ public interface HugeAuthenticator extends Authenticator {
 
     @Override
     default User authenticate(final Map<String, String> credentials)
-                              throws AuthenticationException {
+            throws AuthenticationException {
 
         HugeGraphAuthProxy.resetContext();
 
@@ -118,11 +118,7 @@ public interface HugeAuthenticator extends Authenticator {
     }
 
     default boolean verifyRole(RolePermission role) {
-        if (role == ROLE_NONE || role == null) {
-            return false;
-        } else {
-            return true;
-        }
+        return role != ROLE_NONE && role != null;
     }
 
     void initAdminUser(String password) throws Exception;
@@ -334,7 +330,7 @@ public interface HugeAuthenticator extends Authenticator {
             return null;
         }
 
-        @SuppressWarnings({ "unchecked", "rawtypes" })
+        @SuppressWarnings({"unchecked", "rawtypes"})
         public static RolePerm fromJson(Object role) {
             RolePermission table = RolePermission.fromJson(role);
             return new RolePerm((Map) table.map());
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeFactoryAuthProxy.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeFactoryAuthProxy.java
index 0c748445a..201511fe8 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeFactoryAuthProxy.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeFactoryAuthProxy.java
@@ -65,7 +65,7 @@ import com.google.common.collect.ImmutableSet;
 public final class HugeFactoryAuthProxy {
 
     public static final String GRAPH_FACTORY =
-           "gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy";
+            "gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy";
 
     private static final Set<String> PROTECT_METHODS = ImmutableSet.of("instance");
 
@@ -92,108 +92,385 @@ public final class HugeFactoryAuthProxy {
 
     private static void registerPrivateActions() {
         // Thread
-        Reflection.registerFieldsToFilter(java.lang.Thread.class, "name", "priority", "threadQ", "eetop", "single_step", "daemon", "stillborn", "target", "group", "contextClassLoader", "inheritedAccessControlContext", "threadInitNumber", "threadLocals", "inheritableThreadLocals", "stackSize", "nativeParkEventPointer", "tid", "threadSeqNumber", "threadStatus", "parkBlocker", "blocker", "blockerLock", "EMPTY_STACK_TRACE", "SUBCLASS_IMPLEMENTATION_PERMISSION", "uncaughtExceptionHandler", "d [...]
-        Reflection.registerMethodsToFilter(java.lang.Thread.class, "exit", "dispatchUncaughtException", "clone", "isInterrupted", "registerNatives", "init", "init", "nextThreadNum", "nextThreadID", "blockedOn", "start0", "isCCLOverridden", "auditSubclass", "dumpThreads", "getThreads", "processQueue", "setPriority0", "stop0", "suspend0", "resume0", "interrupt0", "setNativeName");
-        Reflection.registerFieldsToFilter(java.lang.ThreadLocal.class, "threadLocalHashCode", "nextHashCode", "HASH_INCREMENT");
-        Reflection.registerMethodsToFilter(java.lang.ThreadLocal.class, "access$400", "createInheritedMap", "nextHashCode", "initialValue", "setInitialValue", "getMap", "createMap", "childValue");
-        Reflection.registerMethodsToFilter(java.lang.InheritableThreadLocal.class, "getMap", "createMap", "childValue");
+        Reflection.registerFieldsToFilter(java.lang.Thread.class, "name", "priority", "threadQ",
+                                          "eetop", "single_step", "daemon", "stillborn", "target",
+                                          "group", "contextClassLoader",
+                                          "inheritedAccessControlContext", "threadInitNumber",
+                                          "threadLocals", "inheritableThreadLocals", "stackSize",
+                                          "nativeParkEventPointer", "tid", "threadSeqNumber",
+                                          "threadStatus", "parkBlocker", "blocker", "blockerLock",
+                                          "EMPTY_STACK_TRACE", "SUBCLASS_IMPLEMENTATION_PERMISSION",
+                                          "uncaughtExceptionHandler",
+                                          "defaultUncaughtExceptionHandler",
+                                          "threadLocalRandomSeed",
+                                          "threadLocalRandomSecondarySeed");
+        Reflection.registerMethodsToFilter(java.lang.Thread.class, "exit",
+                                           "dispatchUncaughtException", "clone", "isInterrupted",
+                                           "registerNatives", "init", "init", "nextThreadNum",
+                                           "nextThreadID", "blockedOn", "start0", "isCCLOverridden",
+                                           "auditSubclass", "dumpThreads", "getThreads",
+                                           "processQueue", "setPriority0", "stop0", "suspend0",
+                                           "resume0", "interrupt0", "setNativeName");
+        Reflection.registerFieldsToFilter(java.lang.ThreadLocal.class, "threadLocalHashCode",
+                                          "nextHashCode", "HASH_INCREMENT");
+        Reflection.registerMethodsToFilter(java.lang.ThreadLocal.class, "access$400",
+                                           "createInheritedMap", "nextHashCode", "initialValue",
+                                           "setInitialValue", "getMap", "createMap", "childValue");
+        Reflection.registerMethodsToFilter(java.lang.InheritableThreadLocal.class, "getMap",
+                                           "createMap", "childValue");
 
         // HugeGraph
         Reflection.registerFieldsToFilter(StandardAuthenticator.class, "graph");
-        Reflection.registerMethodsToFilter(StandardAuthenticator.class, "initAdminUser", "inputPassword", "graph");
+        Reflection.registerMethodsToFilter(StandardAuthenticator.class, "initAdminUser",
+                                           "inputPassword", "graph");
         Reflection.registerFieldsToFilter(ConfigAuthenticator.class, "tokens");
         Reflection.registerFieldsToFilter(HugeFactoryAuthProxy.class, "PROTECT_METHODS");
-        Reflection.registerMethodsToFilter(HugeFactoryAuthProxy.class, "genRegisterPrivateActions", "registerClass", "registerPrivateActions", "registerPrivateActions", "c");
+        Reflection.registerMethodsToFilter(HugeFactoryAuthProxy.class, "genRegisterPrivateActions",
+                                           "registerClass", "registerPrivateActions",
+                                           "registerPrivateActions", "c");
         Reflection.registerFieldsToFilter(HugeAuthenticator.User.class, "role", "client");
-        Reflection.registerFieldsToFilter(org.apache.tinkerpop.gremlin.server.auth.AuthenticatedUser.class, "name");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.class, "LOG", "hugegraph", "taskScheduler", "authManager", "contexts", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.class, "lambda$0", "access$3", "access$4", "access$2", "access$5", "resetContext", "logUser", "verifyAdminPermission", "verifyStatusPermission", "verifyPermission", "verifySchemaPermission", "verifySchemaPermission", "verifySchemaPermission", "verifySchemaPermission", "verifyNamePermission", "verifyNameExistsPermission", "verifyElemPermission", "verifyElemPermission", "verifyElemPermission", "verifyElemPermission", "verifyResP [...]
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.AuthManagerProxy.class, "authManager", "this$0");
-        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.AuthManagerProxy.class, "currentUsername", "updateCreator");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.TaskSchedulerProxy.class, "taskScheduler", "this$0");
-        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.TaskSchedulerProxy.class, "lambda$0", "lambda$1", "lambda$2", "verifyTaskPermission", "verifyTaskPermission", "verifyTaskPermission", "verifyTaskPermission", "hasTaskPermission");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.GraphTraversalSourceProxy.class, "this$0");
-        Reflection.registerFieldsToFilter(org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource.class, "connection", "graph", "strategies", "bytecode");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.TraversalStrategiesProxy.class, "REST_WOEKER", "serialVersionUID", "strategies", "this$0");
-        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.TraversalStrategiesProxy.class, "translate");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.VariablesProxy.class, "variables", "this$0");
+        Reflection.registerFieldsToFilter(
+                org.apache.tinkerpop.gremlin.server.auth.AuthenticatedUser.class, "name");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.class, "LOG", "hugegraph",
+                                          "taskScheduler", "authManager", "contexts",
+                                          "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.class, "lambda$0", "access$3",
+                                           "access$4", "access$2", "access$5", "resetContext",
+                                           "logUser", "verifyAdminPermission",
+                                           "verifyStatusPermission", "verifyPermission",
+                                           "verifySchemaPermission", "verifySchemaPermission",
+                                           "verifySchemaPermission", "verifySchemaPermission",
+                                           "verifyNamePermission", "verifyNameExistsPermission",
+                                           "verifyElemPermission", "verifyElemPermission",
+                                           "verifyElemPermission", "verifyElemPermission",
+                                           "verifyResPermission", "verifyResPermission",
+                                           "verifyUserPermission", "verifyUserPermission",
+                                           "verifyUserPermission", "getContextString", "access$6",
+                                           "access$7", "lambda$1", "lambda$2", "lambda$3",
+                                           "lambda$4", "lambda$5", "lambda$6", "lambda$7",
+                                           "lambda$8", "lambda$9", "lambda$10", "lambda$11",
+                                           "lambda$12", "lambda$13", "lambda$14", "lambda$15",
+                                           "lambda$16", "lambda$17", "lambda$18", "lambda$19",
+                                           "lambda$20", "lambda$21", "lambda$22", "lambda$23",
+                                           "lambda$24", "access$8", "access$9", "access$10",
+                                           "setContext", "getContext");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.AuthManagerProxy.class, "authManager",
+                                          "this$0");
+        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.AuthManagerProxy.class,
+                                           "currentUsername", "updateCreator");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.TaskSchedulerProxy.class,
+                                          "taskScheduler", "this$0");
+        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.TaskSchedulerProxy.class, "lambda$0",
+                                           "lambda$1", "lambda$2", "verifyTaskPermission",
+                                           "verifyTaskPermission", "verifyTaskPermission",
+                                           "verifyTaskPermission", "hasTaskPermission");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.GraphTraversalSourceProxy.class,
+                                          "this$0");
+        Reflection.registerFieldsToFilter(
+                org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource.class,
+                "connection", "graph", "strategies", "bytecode");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.TraversalStrategiesProxy.class,
+                                          "REST_WOEKER", "serialVersionUID", "strategies",
+                                          "this$0");
+        Reflection.registerMethodsToFilter(HugeGraphAuthProxy.TraversalStrategiesProxy.class,
+                                           "translate");
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.VariablesProxy.class, "variables",
+                                          "this$0");
         Reflection.registerFieldsToFilter(HugeGraphAuthProxy.Context.class, "ADMIN", "user");
-        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.ContextTask.class, "runner", "context");
-        Reflection.registerFieldsToFilter(StandardHugeGraph.class, "LOG", "started", "closed", "mode", "variables", "name", "params", "configuration", "schemaEventHub", "graphEventHub", "indexEventHub", "writeRateLimiter", "readRateLimiter", "taskManager", "authManager", "features", "storeProvider", "tx", "ramtable", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(StandardHugeGraph.class, "lambda$0", "access$3", "access$4", "access$2", "access$5", "access$6", "access$7", "waitUntilAllTasksCompleted", "access$8", "loadStoreProvider", "graphTransaction", "schemaTransaction", "openSchemaTransaction", "checkGraphNotClosed", "openSystemTransaction", "openGraphTransaction", "systemTransaction", "access$9", "access$10", "access$11", "access$12", "access$13", "access$14", "access$15", "access$16", "access$17", "a [...]
-        Reflection.registerFieldsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$StandardHugeGraphParams"), "graph", "this$0");
-        Reflection.registerMethodsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$StandardHugeGraphParams"), "access$1", "graph");
-        Reflection.registerFieldsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$TinkerPopTransaction"), "refs", "opened", "transactions", "this$0", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$TinkerPopTransaction"), "lambda$0", "access$3", "access$2", "lambda$1", "graphTransaction", "schemaTransaction", "systemTransaction", "access$1", "setOpened", "doCommit", "verifyOpened", "doRollback", "doClose", "destroyTransaction", "doOpen", "setClosed", "getOrNewTransaction", "access$0", "resetState");
-        Reflection.registerFieldsToFilter(org.apache.tinkerpop.gremlin.structure.util.AbstractThreadLocalTransaction.class, "readWriteConsumerInternal", "closeConsumerInternal", "transactionListeners");
-        Reflection.registerMethodsToFilter(org.apache.tinkerpop.gremlin.structure.util.AbstractThreadLocalTransaction.class, "doClose", "fireOnCommit", "fireOnRollback", "doReadWrite", "lambda$fireOnRollback$1", "lambda$fireOnCommit$0");
-        Reflection.registerFieldsToFilter(org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.class, "g");
-        Reflection.registerMethodsToFilter(org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.class, "doCommit", "doRollback", "doClose", "doOpen", "fireOnCommit", "fireOnRollback", "doReadWrite");
-        Reflection.registerFieldsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$Txs"), "schemaTx", "systemTx", "graphTx", "openedTime", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$Txs"), "access$2", "access$1", "access$0");
-        Reflection.registerFieldsToFilter(GraphTransaction.class, "indexTx", "addedVertices", "removedVertices", "addedEdges", "removedEdges", "addedProps", "removedProps", "updatedVertices", "updatedEdges", "updatedOldestProps", "locksTable", "checkCustomVertexExist", "checkAdjacentVertexExist", "lazyLoadAdjacentVertex", "ignoreInvalidEntry", "commitPartOfAdjacentEdges", "batchSize", "pageSize", "verticesCapacity", "edgesCapacity", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegra [...]
-        Reflection.registerMethodsToFilter(GraphTransaction.class, "lambda$0", "lambda$1", "lambda$2", "lambda$3", "lambda$4", "lambda$5", "lambda$6", "lambda$7", "lambda$8", "lambda$9", "lambda$10", "lambda$11", "lambda$12", "lambda$13", "lambda$14", "lambda$15", "lambda$16", "lambda$17", "lambda$18", "lambda$19", "access$1", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy", "indexTransaction", "indexTransaction", "beforeWrite", "prepareCommit", "verticesInTxSize", "edgesInTxS [...]
+        Reflection.registerFieldsToFilter(HugeGraphAuthProxy.ContextTask.class, "runner",
+                                          "context");
+        Reflection.registerFieldsToFilter(StandardHugeGraph.class, "LOG", "started", "closed",
+                                          "mode", "variables", "name", "params", "configuration",
+                                          "schemaEventHub", "graphEventHub", "indexEventHub",
+                                          "writeRateLimiter", "readRateLimiter", "taskManager",
+                                          "authManager", "features", "storeProvider", "tx",
+                                          "ramtable", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(StandardHugeGraph.class, "lambda$0", "access$3",
+                                           "access$4", "access$2", "access$5", "access$6",
+                                           "access$7", "waitUntilAllTasksCompleted", "access$8",
+                                           "loadStoreProvider", "graphTransaction",
+                                           "schemaTransaction", "openSchemaTransaction",
+                                           "checkGraphNotClosed", "openSystemTransaction",
+                                           "openGraphTransaction", "systemTransaction", "access$9",
+                                           "access$10", "access$11", "access$12", "access$13",
+                                           "access$14", "access$15", "access$16", "access$17",
+                                           "access$18", "serializer", "loadSchemaStore",
+                                           "loadSystemStore", "loadGraphStore", "closeTx",
+                                           "analyzer", "serverInfoManager", "reloadRamtable",
+                                           "reloadRamtable", "access$19", "access$20", "access$21");
+        Reflection.registerFieldsToFilter(
+                loadClass("org.apache.hugegraph.StandardHugeGraph$StandardHugeGraphParams"),
+                "graph", "this$0");
+        Reflection.registerMethodsToFilter(
+                loadClass("org.apache.hugegraph.StandardHugeGraph$StandardHugeGraphParams"),
+                "access$1", "graph");
+        Reflection.registerFieldsToFilter(
+                loadClass("org.apache.hugegraph.StandardHugeGraph$TinkerPopTransaction"), "refs",
+                "opened", "transactions", "this$0", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(
+                loadClass("org.apache.hugegraph.StandardHugeGraph$TinkerPopTransaction"),
+                "lambda$0", "access$3", "access$2", "lambda$1", "graphTransaction",
+                "schemaTransaction", "systemTransaction", "access$1", "setOpened", "doCommit",
+                "verifyOpened", "doRollback", "doClose", "destroyTransaction", "doOpen",
+                "setClosed", "getOrNewTransaction", "access$0", "resetState");
+        Reflection.registerFieldsToFilter(
+                org.apache.tinkerpop.gremlin.structure.util.AbstractThreadLocalTransaction.class,
+                "readWriteConsumerInternal", "closeConsumerInternal", "transactionListeners");
+        Reflection.registerMethodsToFilter(
+                org.apache.tinkerpop.gremlin.structure.util.AbstractThreadLocalTransaction.class,
+                "doClose", "fireOnCommit", "fireOnRollback", "doReadWrite",
+                "lambda$fireOnRollback$1", "lambda$fireOnCommit$0");
+        Reflection.registerFieldsToFilter(
+                org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.class, "g");
+        Reflection.registerMethodsToFilter(
+                org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.class, "doCommit",
+                "doRollback", "doClose", "doOpen", "fireOnCommit", "fireOnRollback", "doReadWrite");
+        Reflection.registerFieldsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$Txs"),
+                                          "schemaTx", "systemTx", "graphTx", "openedTime",
+                                          "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(loadClass("org.apache.hugegraph.StandardHugeGraph$Txs"),
+                                           "access$2", "access$1", "access$0");
+        Reflection.registerFieldsToFilter(GraphTransaction.class, "indexTx", "addedVertices",
+                                          "removedVertices", "addedEdges", "removedEdges",
+                                          "addedProps", "removedProps", "updatedVertices",
+                                          "updatedEdges", "updatedOldestProps", "locksTable",
+                                          "checkCustomVertexExist", "checkAdjacentVertexExist",
+                                          "lazyLoadAdjacentVertex", "ignoreInvalidEntry",
+                                          "commitPartOfAdjacentEdges", "batchSize", "pageSize",
+                                          "verticesCapacity", "edgesCapacity",
+                                          "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy");
+        Reflection.registerMethodsToFilter(GraphTransaction.class, "lambda$0", "lambda$1",
+                                           "lambda$2", "lambda$3", "lambda$4", "lambda$5",
+                                           "lambda$6", "lambda$7", "lambda$8", "lambda$9",
+                                           "lambda$10", "lambda$11", "lambda$12", "lambda$13",
+                                           "lambda$14", "lambda$15", "lambda$16", "lambda$17",
+                                           "lambda$18", "lambda$19", "access$1",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy",
+                                           "indexTransaction", "indexTransaction", "beforeWrite",
+                                           "prepareCommit", "verticesInTxSize", "edgesInTxSize",
+                                           "checkTxVerticesCapacity", "checkTxEdgesCapacity",
+                                           "verticesInTxUpdated", "verticesInTxRemoved",
+                                           "removingEdgeOwner", "prepareDeletions",
+                                           "prepareDeletions", "prepareUpdates", "prepareAdditions",
+                                           "checkVertexExistIfCustomizedId",
+                                           "checkAggregateProperty", "checkAggregateProperty",
+                                           "checkNonnullProperty", "queryEdgesFromBackend",
+                                           "commitPartOfEdgeDeletions", "optimizeQueries",
+                                           "checkVertexLabel", "checkId",
+                                           "queryVerticesFromBackend", "joinTxVertices",
+                                           "joinTxEdges", "lockForUpdateProperty", "optimizeQuery",
+                                           "verifyVerticesConditionQuery",
+                                           "verifyEdgesConditionQuery", "indexQuery",
+                                           "joinTxRecords", "propertyUpdated", "parseEntry",
+                                           "traverseByLabel", "reset", "queryVerticesByIds",
+                                           "filterUnmatchedRecords", "skipOffsetOrStopLimit",
+                                           "filterExpiredResultFromFromBackend", "queryEdgesByIds",
+                                           "matchEdgeSortKeys", "rightResultFromIndexQuery");
         Reflection.registerFieldsToFilter(IndexableTransaction.class, "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(IndexableTransaction.class, "indexTransaction", "commit2Backend", "reset");
-        Reflection.registerFieldsToFilter(AbstractTransaction.class, "LOG", "ownerThread", "autoCommit", "closed", "committing", "committing2Backend", "graph", "store", "mutation", "serializer", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(AbstractTransaction.class, "beforeWrite", "prepareCommit", "params", "mutation", "commit2Backend", "autoCommit", "beforeRead", "afterWrite", "afterRead", "commitMutation2Backend", "checkOwnerThread", "doAction", "store", "reset");
+        Reflection.registerMethodsToFilter(IndexableTransaction.class, "indexTransaction",
+                                           "commit2Backend", "reset");
+        Reflection.registerFieldsToFilter(AbstractTransaction.class, "LOG", "ownerThread",
+                                          "autoCommit", "closed", "committing",
+                                          "committing2Backend", "graph", "store", "mutation",
+                                          "serializer", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(AbstractTransaction.class, "beforeWrite",
+                                           "prepareCommit", "params", "mutation", "commit2Backend",
+                                           "autoCommit", "beforeRead", "afterWrite", "afterRead",
+                                           "commitMutation2Backend", "checkOwnerThread", "doAction",
+                                           "store", "reset");
         Reflection.registerFieldsToFilter(HugeFactory.class, "LOG", "NAME_REGEX", "graphs");
         Reflection.registerMethodsToFilter(HugeFactory.class, "lambda$0");
-        Reflection.registerFieldsToFilter(SchemaElement.class, "graph", "id", "name", "userdata", "status");
-        Reflection.registerFieldsToFilter(HugeVertex.class, "EMPTY_SET", "id", "label", "edges", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys");
-        Reflection.registerMethodsToFilter(HugeVertex.class, "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy", "newProperty", "newProperty", "tx", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys", "checkIdLength", "onUpdateProperty", "ensureFilledProperties", "clone", "clone");
-        Reflection.registerFieldsToFilter(HugeElement.class, "EMPTY_MAP", "MAX_PROPERTIES", "graph", "properties", "expiredTime", "removed", "fresh", "propLoaded", "defaultValueUpdated", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Cardinality");
-        Reflection.registerMethodsToFilter(HugeElement.class, "removed", "addProperty", "newProperty", "tx", "onUpdateProperty", "ensureFilledProperties", "propLoaded", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Cardinality", "getIdValue", "fresh", "updateToDefaultValueIfNone", "copyProperties");
-        Reflection.registerFieldsToFilter(HugeEdge.class, "id", "label", "name", "sourceVertex", "targetVertex", "isOutEdge", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys", "$SWITCH_TABLE$org$apache$tinkerpop$gremlin$structure$Direction");
-        Reflection.registerMethodsToFilter(HugeEdge.class, "checkAdjacentVertexExist", "newProperty", "newProperty", "tx", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys", "onUpdateProperty", "ensureFilledProperties", "$SWITCH_TABLE$org$apache$tinkerpop$gremlin$structure$Direction", "clone", "clone");
+        Reflection.registerFieldsToFilter(SchemaElement.class, "graph", "id", "name", "userdata",
+                                          "status");
+        Reflection.registerFieldsToFilter(HugeVertex.class, "EMPTY_SET", "id", "label", "edges",
+                                          "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys");
+        Reflection.registerMethodsToFilter(HugeVertex.class,
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy",
+                                           "newProperty", "newProperty", "tx",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys",
+                                           "checkIdLength", "onUpdateProperty",
+                                           "ensureFilledProperties", "clone", "clone");
+        Reflection.registerFieldsToFilter(HugeElement.class, "EMPTY_MAP", "MAX_PROPERTIES", "graph",
+                                          "properties", "expiredTime", "removed", "fresh",
+                                          "propLoaded", "defaultValueUpdated",
+                                          "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Cardinality");
+        Reflection.registerMethodsToFilter(HugeElement.class, "removed", "addProperty",
+                                           "newProperty", "tx", "onUpdateProperty",
+                                           "ensureFilledProperties", "propLoaded",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Cardinality",
+                                           "getIdValue", "fresh", "updateToDefaultValueIfNone",
+                                           "copyProperties");
+        Reflection.registerFieldsToFilter(HugeEdge.class, "id", "label", "name", "sourceVertex",
+                                          "targetVertex", "isOutEdge", "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys",
+                                          "$SWITCH_TABLE$org$apache$tinkerpop$gremlin$structure$Direction");
+        Reflection.registerMethodsToFilter(HugeEdge.class, "checkAdjacentVertexExist",
+                                           "newProperty", "newProperty", "tx",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$HugeKeys",
+                                           "onUpdateProperty", "ensureFilledProperties",
+                                           "$SWITCH_TABLE$org$apache$tinkerpop$gremlin$structure$Direction",
+                                           "clone", "clone");
         Reflection.registerFieldsToFilter(HugeProperty.class, "owner", "pkey", "value");
-        Reflection.registerFieldsToFilter(HugeVariables.class, "LOG", "VARIABLES", "VARIABLE_KEY", "VARIABLE_TYPE", "BYTE_VALUE", "BOOLEAN_VALUE", "INTEGER_VALUE", "LONG_VALUE", "FLOAT_VALUE", "DOUBLE_VALUE", "STRING_VALUE", "LIST", "SET", "TYPES", "params", "graph");
-        Reflection.registerMethodsToFilter(HugeVariables.class, "createPropertyKey", "queryAllVariableVertices", "queryVariableVertex", "createVariableVertex", "removeVariableVertex", "extractSingleObject", "setProperty");
+        Reflection.registerFieldsToFilter(HugeVariables.class, "LOG", "VARIABLES", "VARIABLE_KEY",
+                                          "VARIABLE_TYPE", "BYTE_VALUE", "BOOLEAN_VALUE",
+                                          "INTEGER_VALUE", "LONG_VALUE", "FLOAT_VALUE",
+                                          "DOUBLE_VALUE", "STRING_VALUE", "LIST", "SET", "TYPES",
+                                          "params", "graph");
+        Reflection.registerMethodsToFilter(HugeVariables.class, "createPropertyKey",
+                                           "queryAllVariableVertices", "queryVariableVertex",
+                                           "createVariableVertex", "removeVariableVertex",
+                                           "extractSingleObject", "setProperty");
         Reflection.registerFieldsToFilter(SchemaManager.class, "transaction", "graph");
-        Reflection.registerMethodsToFilter(SchemaManager.class, "lambda$0", "lambda$1", "lambda$2", "lambda$3", "checkExists");
-        Reflection.registerFieldsToFilter(PropertyKeyBuilder.class, "id", "name", "dataType", "cardinality", "aggregateType", "checkExist", "userdata", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(PropertyKeyBuilder.class, "lambda$0", "checkStableVars", "checkAggregateType", "hasSameProperties");
+        Reflection.registerMethodsToFilter(SchemaManager.class, "lambda$0", "lambda$1", "lambda$2",
+                                           "lambda$3", "checkExists");
+        Reflection.registerFieldsToFilter(PropertyKeyBuilder.class, "id", "name", "dataType",
+                                          "cardinality", "aggregateType", "checkExist", "userdata",
+                                          "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(PropertyKeyBuilder.class, "lambda$0", "checkStableVars",
+                                           "checkAggregateType", "hasSameProperties");
         Reflection.registerFieldsToFilter(AbstractBuilder.class, "transaction", "graph");
-        Reflection.registerMethodsToFilter(AbstractBuilder.class, "rebuildIndex", "graph", "checkSchemaName", "validOrGenerateId", "lockCheckAndCreateSchema", "propertyKeyOrNull", "checkSchemaIdIfRestoringMode", "vertexLabelOrNull", "edgeLabelOrNull", "indexLabelOrNull", "updateSchemaStatus");
-        Reflection.registerFieldsToFilter(VertexLabelBuilder.class, "id", "name", "idStrategy", "properties", "primaryKeys", "nullableKeys", "ttl", "ttlStartTime", "enableLabelIndex", "userdata", "checkExist", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy");
-        Reflection.registerMethodsToFilter(VertexLabelBuilder.class, "lambda$0", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy", "checkStableVars", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action", "checkProperties", "checkNullableKeys", "checkIdStrategy", "checkPrimaryKeys", "hasSameProperties", "checkTtl", "checkUserdata", "mapPkId2Name", "mapPkId2Name");
-        Reflection.registerFieldsToFilter(EdgeLabelBuilder.class, "id", "name", "sourceLabel", "targetLabel", "frequency", "properties", "sortKeys", "nullableKeys", "ttl", "ttlStartTime", "enableLabelIndex", "userdata", "checkExist", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action");
-        Reflection.registerMethodsToFilter(EdgeLabelBuilder.class, "lambda$0", "checkStableVars", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action", "checkProperties", "checkNullableKeys", "checkSortKeys", "checkRelation", "hasSameProperties", "checkTtl", "checkUserdata", "mapPkId2Name", "mapPkId2Name");
-        Reflection.registerFieldsToFilter(IndexLabelBuilder.class, "id", "name", "baseType", "baseValue", "indexType", "indexFields", "userdata", "checkExist", "rebuild", "$assertionsDisabled", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$DataType", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IndexType");
-        Reflection.registerMethodsToFilter(IndexLabelBuilder.class, "lambda$0", "checkStableVars", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$DataType", "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IndexType", "checkBaseType", "checkIndexType", "checkFields4Range", "loadElement", "checkFields", "checkRepeatIndex", "checkRepeatIndex", "checkRepeatIndex", "checkPrimaryKeyIndex", "checkRepeatRangeIndex", "checkRepeatSearchIndex", "checkRepeatSecondaryIndex", "checkRepeatShardIndex", " [...]
-        Reflection.registerFieldsToFilter(TaskManager.class, "LOG", "SCHEDULE_PERIOD", "THREADS", "MANAGER", "schedulers", "taskExecutor", "taskDbExecutor", "serverInfoDbExecutor", "schedulerExecutor", "contexts", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(TaskManager.class, "lambda$0", "resetContext", "closeTaskTx", "setContext", "instance", "closeSchedulerTx", "notifyNewTask", "scheduleOrExecuteJob", "scheduleOrExecuteJobForGraph");
-        Reflection.registerFieldsToFilter(StandardTaskScheduler.class, "LOG", "graph", "serverManager", "taskExecutor", "taskDbExecutor", "eventListener", "tasks", "taskTx", "NO_LIMIT", "PAGE_SIZE", "QUERY_INTERVAL", "MAX_PENDING_TASKS", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(StandardTaskScheduler.class, "lambda$0", "lambda$1", "lambda$2", "lambda$3", "lambda$4", "lambda$5", "lambda$6", "lambda$7", "tx", "listenChanges", "unlistenChanges", "submitTask", "queryTask", "queryTask", "queryTask", "call", "call", "remove", "sleep", "taskDone", "serverManager", "supportsPaging", "restore", "checkOnMasterNode", "waitUntilTaskCompleted", "scheduleTasks", "executeTasksOnWorker", "cancelTasksOnWorker");
-        Reflection.registerFieldsToFilter(HugeTask.class, "LOG", "DECOMPRESS_RATIO", "scheduler", "callable", "type", "name", "id", "parent", "dependencies", "description", "context", "create", "server", "load", "status", "progress", "update", "retries", "input", "result", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(HugeTask.class, "property", "scheduler", "scheduler", "asArray", "checkPropertySize", "checkPropertySize", "checkDependenciesSuccess", "toOrderSet", "done", "callable", "setException", "set", "result", "status");
-        Reflection.registerFieldsToFilter(TaskCallable.class, "LOG", "ERROR_COMMIT", "ERROR_MESSAGES", "task", "graph", "lastSaveTime", "saveInterval");
-        Reflection.registerMethodsToFilter(TaskCallable.class, "graph", "closeTx", "cancelled", "done", "task", "save", "needSaveWithEx");
+        Reflection.registerMethodsToFilter(AbstractBuilder.class, "rebuildIndex", "graph",
+                                           "checkSchemaName", "validOrGenerateId",
+                                           "lockCheckAndCreateSchema", "propertyKeyOrNull",
+                                           "checkSchemaIdIfRestoringMode", "vertexLabelOrNull",
+                                           "edgeLabelOrNull", "indexLabelOrNull",
+                                           "updateSchemaStatus");
+        Reflection.registerFieldsToFilter(VertexLabelBuilder.class, "id", "name", "idStrategy",
+                                          "properties", "primaryKeys", "nullableKeys", "ttl",
+                                          "ttlStartTime", "enableLabelIndex", "userdata",
+                                          "checkExist", "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy");
+        Reflection.registerMethodsToFilter(VertexLabelBuilder.class, "lambda$0",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IdStrategy",
+                                           "checkStableVars",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action",
+                                           "checkProperties", "checkNullableKeys",
+                                           "checkIdStrategy", "checkPrimaryKeys",
+                                           "hasSameProperties", "checkTtl", "checkUserdata",
+                                           "mapPkId2Name", "mapPkId2Name");
+        Reflection.registerFieldsToFilter(EdgeLabelBuilder.class, "id", "name", "sourceLabel",
+                                          "targetLabel", "frequency", "properties", "sortKeys",
+                                          "nullableKeys", "ttl", "ttlStartTime", "enableLabelIndex",
+                                          "userdata", "checkExist", "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action");
+        Reflection.registerMethodsToFilter(EdgeLabelBuilder.class, "lambda$0", "checkStableVars",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$Action",
+                                           "checkProperties", "checkNullableKeys", "checkSortKeys",
+                                           "checkRelation", "hasSameProperties", "checkTtl",
+                                           "checkUserdata", "mapPkId2Name", "mapPkId2Name");
+        Reflection.registerFieldsToFilter(IndexLabelBuilder.class, "id", "name", "baseType",
+                                          "baseValue", "indexType", "indexFields", "userdata",
+                                          "checkExist", "rebuild", "$assertionsDisabled",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$DataType",
+                                          "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IndexType");
+        Reflection.registerMethodsToFilter(IndexLabelBuilder.class, "lambda$0", "checkStableVars",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$DataType",
+                                           "$SWITCH_TABLE$com$baidu$hugegraph$type$define$IndexType",
+                                           "checkBaseType", "checkIndexType", "checkFields4Range",
+                                           "loadElement", "checkFields", "checkRepeatIndex",
+                                           "checkRepeatIndex", "checkRepeatIndex",
+                                           "checkPrimaryKeyIndex", "checkRepeatRangeIndex",
+                                           "checkRepeatSearchIndex", "checkRepeatSecondaryIndex",
+                                           "checkRepeatShardIndex", "checkRepeatUniqueIndex",
+                                           "removeSubIndex", "hasSubIndex", "allStringIndex",
+                                           "oneNumericField", "hasSameProperties");
+        Reflection.registerFieldsToFilter(TaskManager.class, "LOG", "SCHEDULE_PERIOD", "THREADS",
+                                          "MANAGER", "schedulers", "taskExecutor", "taskDbExecutor",
+                                          "serverInfoDbExecutor", "schedulerExecutor", "contexts",
+                                          "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(TaskManager.class, "lambda$0", "resetContext",
+                                           "closeTaskTx", "setContext", "instance",
+                                           "closeSchedulerTx", "notifyNewTask",
+                                           "scheduleOrExecuteJob", "scheduleOrExecuteJobForGraph");
+        Reflection.registerFieldsToFilter(StandardTaskScheduler.class, "LOG", "graph",
+                                          "serverManager", "taskExecutor", "taskDbExecutor",
+                                          "eventListener", "tasks", "taskTx", "NO_LIMIT",
+                                          "PAGE_SIZE", "QUERY_INTERVAL", "MAX_PENDING_TASKS",
+                                          "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(StandardTaskScheduler.class, "lambda$0", "lambda$1",
+                                           "lambda$2", "lambda$3", "lambda$4", "lambda$5",
+                                           "lambda$6", "lambda$7", "tx", "listenChanges",
+                                           "unlistenChanges", "submitTask", "queryTask",
+                                           "queryTask", "queryTask", "call", "call", "remove",
+                                           "sleep", "taskDone", "serverManager", "supportsPaging",
+                                           "restore", "checkOnMasterNode", "waitUntilTaskCompleted",
+                                           "scheduleTasks", "executeTasksOnWorker",
+                                           "cancelTasksOnWorker");
+        Reflection.registerFieldsToFilter(HugeTask.class, "LOG", "DECOMPRESS_RATIO", "scheduler",
+                                          "callable", "type", "name", "id", "parent",
+                                          "dependencies", "description", "context", "create",
+                                          "server", "load", "status", "progress", "update",
+                                          "retries", "input", "result", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(HugeTask.class, "property", "scheduler", "scheduler",
+                                           "asArray", "checkPropertySize", "checkPropertySize",
+                                           "checkDependenciesSuccess", "toOrderSet", "done",
+                                           "callable", "setException", "set", "result", "status");
+        Reflection.registerFieldsToFilter(TaskCallable.class, "LOG", "ERROR_COMMIT",
+                                          "ERROR_MESSAGES", "task", "graph", "lastSaveTime",
+                                          "saveInterval");
+        Reflection.registerMethodsToFilter(TaskCallable.class, "graph", "closeTx", "cancelled",
+                                           "done", "task", "save", "needSaveWithEx");
         Reflection.registerFieldsToFilter(TaskCallable.SysTaskCallable.class, "params");
         Reflection.registerMethodsToFilter(TaskCallable.SysTaskCallable.class, "params", "params");
-        Reflection.registerFieldsToFilter(StandardAuthManager.class, "CACHE_EXPIRE", "graph", "eventListener", "usersCache", "users", "groups", "targets", "belong", "access", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(StandardAuthManager.class, "lambda$0", "listenChanges", "unlistenChanges", "invalidCache", "initSchemaIfNeeded", "rolePermission", "rolePermission", "rolePermission", "cache");
+        Reflection.registerFieldsToFilter(StandardAuthManager.class, "CACHE_EXPIRE", "graph",
+                                          "eventListener", "usersCache", "users", "groups",
+                                          "targets", "belong", "access", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(StandardAuthManager.class, "lambda$0", "listenChanges",
+                                           "unlistenChanges", "invalidCache", "initSchemaIfNeeded",
+                                           "rolePermission", "rolePermission", "rolePermission",
+                                           "cache");
         Reflection.registerFieldsToFilter(SchemaDefine.class, "graph", "label");
-        Reflection.registerMethodsToFilter(SchemaDefine.class, "schema", "createPropertyKey", "createPropertyKey", "createPropertyKey", "existEdgeLabel", "createRangeIndex", "unhideField", "hideField", "existVertexLabel", "initProperties");
-        Reflection.registerFieldsToFilter(EntityManager.class, "graph", "label", "deser", "NO_LIMIT", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(EntityManager.class, "toList", "graph", "tx", "commitOrRollback", "unhideLabel", "queryById", "queryEntity", "constructVertex", "save", "query");
-        Reflection.registerFieldsToFilter(RelationshipManager.class, "graph", "label", "deser", "NO_LIMIT", "$assertionsDisabled");
-        Reflection.registerMethodsToFilter(RelationshipManager.class, "lambda$0", "toList", "graph", "tx", "commitOrRollback", "unhideLabel", "queryById", "queryRelationship", "newVertex", "save");
-        Reflection.registerFieldsToFilter(CacheManager.class, "LOG", "INSTANCE", "TIMER_TICK_PERIOD", "LOG_TICK_COST_TIME", "caches", "timer");
-        Reflection.registerMethodsToFilter(CacheManager.class, "access$0", "scheduleTimer", "instance");
-        Reflection.registerFieldsToFilter(org.apache.hugegraph.concurrent.LockManager.class, "INSTANCE", "lockGroupMap");
-        Reflection.registerMethodsToFilter(org.apache.hugegraph.concurrent.LockManager.class, "instance");
-        Reflection.registerFieldsToFilter(ServerReporter.class, "instance", "gauges", "counters", "histograms", "meters", "timers");
+        Reflection.registerMethodsToFilter(SchemaDefine.class, "schema", "createPropertyKey",
+                                           "createPropertyKey", "createPropertyKey",
+                                           "existEdgeLabel", "createRangeIndex", "unhideField",
+                                           "hideField", "existVertexLabel", "initProperties");
+        Reflection.registerFieldsToFilter(EntityManager.class, "graph", "label", "deser",
+                                          "NO_LIMIT", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(EntityManager.class, "toList", "graph", "tx",
+                                           "commitOrRollback", "unhideLabel", "queryById",
+                                           "queryEntity", "constructVertex", "save", "query");
+        Reflection.registerFieldsToFilter(RelationshipManager.class, "graph", "label", "deser",
+                                          "NO_LIMIT", "$assertionsDisabled");
+        Reflection.registerMethodsToFilter(RelationshipManager.class, "lambda$0", "toList", "graph",
+                                           "tx", "commitOrRollback", "unhideLabel", "queryById",
+                                           "queryRelationship", "newVertex", "save");
+        Reflection.registerFieldsToFilter(CacheManager.class, "LOG", "INSTANCE",
+                                          "TIMER_TICK_PERIOD", "LOG_TICK_COST_TIME", "caches",
+                                          "timer");
+        Reflection.registerMethodsToFilter(CacheManager.class, "access$0", "scheduleTimer",
+                                           "instance");
+        Reflection.registerFieldsToFilter(org.apache.hugegraph.concurrent.LockManager.class,
+                                          "INSTANCE", "lockGroupMap");
+        Reflection.registerMethodsToFilter(org.apache.hugegraph.concurrent.LockManager.class,
+                                           "instance");
+        Reflection.registerFieldsToFilter(ServerReporter.class, "instance", "gauges", "counters",
+                                          "histograms", "meters", "timers");
         Reflection.registerMethodsToFilter(ServerReporter.class, "instance", "instance");
-        Reflection.registerFieldsToFilter(com.codahale.metrics.ScheduledReporter.class, "LOG", "FACTORY_ID", "registry", "executor", "shutdownExecutorOnStop", "disabledMetricAttributes", "scheduledFuture", "filter", "durationFactor", "durationUnit", "rateFactor", "rateUnit");
-        Reflection.registerMethodsToFilter(com.codahale.metrics.ScheduledReporter.class, "convertDuration", "convertRate", "getRateUnit", "getDurationUnit", "isShutdownExecutorOnStop", "getDisabledMetricAttributes", "calculateRateUnit", "createDefaultExecutor", "lambda$start$0", "start");
+        Reflection.registerFieldsToFilter(com.codahale.metrics.ScheduledReporter.class, "LOG",
+                                          "FACTORY_ID", "registry", "executor",
+                                          "shutdownExecutorOnStop", "disabledMetricAttributes",
+                                          "scheduledFuture", "filter", "durationFactor",
+                                          "durationUnit", "rateFactor", "rateUnit");
+        Reflection.registerMethodsToFilter(com.codahale.metrics.ScheduledReporter.class,
+                                           "convertDuration", "convertRate", "getRateUnit",
+                                           "getDurationUnit", "isShutdownExecutorOnStop",
+                                           "getDisabledMetricAttributes", "calculateRateUnit",
+                                           "createDefaultExecutor", "lambda$start$0", "start");
         Reflection.registerFieldsToFilter(JsonSerializer.class, "LBUF_SIZE", "INSTANCE");
         Reflection.registerMethodsToFilter(JsonSerializer.class, "writeIterator", "instance");
-        Reflection.registerFieldsToFilter(HugeVertexStepStrategy.class, "serialVersionUID", "INSTANCE");
+        Reflection.registerFieldsToFilter(HugeVertexStepStrategy.class, "serialVersionUID",
+                                          "INSTANCE");
         Reflection.registerMethodsToFilter(HugeVertexStepStrategy.class, "instance");
-        Reflection.registerFieldsToFilter(HugeGraphStepStrategy.class, "serialVersionUID", "INSTANCE");
+        Reflection.registerFieldsToFilter(HugeGraphStepStrategy.class, "serialVersionUID",
+                                          "INSTANCE");
         Reflection.registerMethodsToFilter(HugeGraphStepStrategy.class, "instance");
-        Reflection.registerFieldsToFilter(HugeCountStepStrategy.class, "serialVersionUID", "INSTANCE");
+        Reflection.registerFieldsToFilter(HugeCountStepStrategy.class, "serialVersionUID",
+                                          "INSTANCE");
         Reflection.registerMethodsToFilter(HugeCountStepStrategy.class, "lambda$0", "instance");
 
         // Enable this line to generate registration statement
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeGraphAuthProxy.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeGraphAuthProxy.java
index 389d15b1c..dcb9db99c 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeGraphAuthProxy.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/HugeGraphAuthProxy.java
@@ -149,7 +149,7 @@ public final class HugeGraphAuthProxy implements HugeGraph {
 
     @Override
     public <C extends GraphComputer> C compute(Class<C> clazz)
-                                               throws IllegalArgumentException {
+            throws IllegalArgumentException {
         this.verifyAnyPermission();
         return this.hugegraph.compute(clazz);
     }
@@ -166,7 +166,7 @@ public final class HugeGraphAuthProxy implements HugeGraph {
         return new GraphTraversalSourceProxy(this);
     }
 
-    @SuppressWarnings({ "rawtypes", "deprecation" })
+    @SuppressWarnings({"rawtypes", "deprecation"})
     @Override
     public <I extends Io> I io(final Io.Builder<I> builder) {
         this.verifyAnyPermission();
@@ -834,14 +834,14 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends AuthElement> V verifyUserPermission(
-                                      HugePermission actionPerm,
-                                      V elementFetcher) {
+            HugePermission actionPerm,
+            V elementFetcher) {
         return verifyUserPermission(actionPerm, true, () -> elementFetcher);
     }
 
     private <V extends AuthElement> List<V> verifyUserPermission(
-                                            HugePermission actionPerm,
-                                            List<V> elems) {
+            HugePermission actionPerm,
+            List<V> elems) {
         List<V> results = new ArrayList<>();
         for (V elem : elems) {
             V r = verifyUserPermission(actionPerm, false, () -> elem);
@@ -853,9 +853,9 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends AuthElement> V verifyUserPermission(
-                                      HugePermission actionPerm,
-                                      boolean throwIfNoPerm,
-                                      Supplier<V> elementFetcher) {
+            HugePermission actionPerm,
+            boolean throwIfNoPerm,
+            Supplier<V> elementFetcher) {
         return verifyResPermission(actionPerm, throwIfNoPerm, () -> {
             String graph = this.hugegraph.name();
             V elem = elementFetcher.get();
@@ -871,14 +871,14 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends HugeElement> V verifyElemPermission(
-                                      HugePermission actionPerm,
-                                      Supplier<V> elementFetcher) {
+            HugePermission actionPerm,
+            Supplier<V> elementFetcher) {
         return verifyElemPermission(actionPerm, true, elementFetcher);
     }
 
     private <V extends Element> Iterator<V> verifyElemPermission(
-                                            HugePermission actionPerm,
-                                            Iterator<V> elems) {
+            HugePermission actionPerm,
+            Iterator<V> elems) {
         return new FilterIterator<>(elems, elem -> {
             V r = verifyElemPermission(actionPerm, false, () -> elem);
             return r != null;
@@ -886,9 +886,9 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends Element> V verifyElemPermission(
-                                  HugePermission actionPerm,
-                                  boolean throwIfNoPerm,
-                                  Supplier<V> elementFetcher) {
+            HugePermission actionPerm,
+            boolean throwIfNoPerm,
+            Supplier<V> elementFetcher) {
         return verifyResPermission(actionPerm, throwIfNoPerm, () -> {
             String graph = this.hugegraph.name();
             HugeElement elem = (HugeElement) elementFetcher.get();
@@ -918,8 +918,8 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends SchemaElement> Collection<V> verifySchemaPermission(
-                                                    HugePermission actionPerm,
-                                                    Collection<V> schemas) {
+            HugePermission actionPerm,
+            Collection<V> schemas) {
         List<V> results = new ArrayList<>();
         for (V schema : schemas) {
             V r = verifySchemaPermission(actionPerm, false, () -> schema);
@@ -931,15 +931,15 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private <V extends SchemaElement> V verifySchemaPermission(
-                                        HugePermission actionPerm,
-                                        Supplier<V> schemaFetcher) {
+            HugePermission actionPerm,
+            Supplier<V> schemaFetcher) {
         return verifySchemaPermission(actionPerm, true, schemaFetcher);
     }
 
     private <V extends SchemaElement> V verifySchemaPermission(
-                                        HugePermission actionPerm,
-                                        boolean throwIfNoPerm,
-                                        Supplier<V> schemaFetcher) {
+            HugePermission actionPerm,
+            boolean throwIfNoPerm,
+            Supplier<V> schemaFetcher) {
         return verifyResPermission(actionPerm, throwIfNoPerm, () -> {
             String graph = this.hugegraph.name();
             SchemaElement elem = schemaFetcher.get();
@@ -1101,21 +1101,21 @@ public final class HugeGraphAuthProxy implements HugeGraph {
 
         @Override
         public <V> HugeTask<V> waitUntilTaskCompleted(Id id, long seconds)
-                                                      throws TimeoutException {
+                throws TimeoutException {
             verifyAnyPermission();
             return this.taskScheduler.waitUntilTaskCompleted(id, seconds);
         }
 
         @Override
         public <V> HugeTask<V> waitUntilTaskCompleted(Id id)
-                                                      throws TimeoutException {
+                throws TimeoutException {
             verifyAnyPermission();
             return this.taskScheduler.waitUntilTaskCompleted(id);
         }
 
         @Override
         public void waitUntilAllTasksCompleted(long seconds)
-                                               throws TimeoutException {
+                throws TimeoutException {
             verifyAnyPermission();
             this.taskScheduler.waitUntilAllTasksCompleted(seconds);
         }
@@ -1166,8 +1166,8 @@ public final class HugeGraphAuthProxy implements HugeGraph {
         }
 
         private <V> Iterator<HugeTask<V>> verifyTaskPermission(
-                                          HugePermission actionPerm,
-                                          Iterator<HugeTask<V>> tasks) {
+                HugePermission actionPerm,
+                Iterator<HugeTask<V>> tasks) {
             return new FilterIterator<>(tasks, task -> {
                 return verifyTaskPermission(actionPerm, false, task) != null;
             });
@@ -1727,7 +1727,7 @@ public final class HugeGraphAuthProxy implements HugeGraph {
         @SuppressWarnings({"unchecked"})
         @Override
         public TraversalStrategies removeStrategies(
-               Class<? extends TraversalStrategy>... strategyClasses) {
+                Class<? extends TraversalStrategy>... strategyClasses) {
             return this.strategies.removeStrategies(strategyClasses);
         }
 
@@ -1756,14 +1756,14 @@ public final class HugeGraphAuthProxy implements HugeGraph {
     }
 
     private final class TraversalStrategyProxy<T extends TraversalStrategy<?>>
-                  implements TraversalStrategy<T> {
+            implements TraversalStrategy<T> {
 
         private static final long serialVersionUID = 2071829024642435735L;
 
         private final TraversalStrategy<T> origin;
 
         public TraversalStrategyProxy(TraversalStrategy<?> origin) {
-            @SuppressWarnings({ "rawtypes", "unchecked" })
+            @SuppressWarnings({"rawtypes", "unchecked"})
             TraversalStrategy<T> strategy = (TraversalStrategy) origin;
             this.origin = strategy;
         }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/StandardAuthenticator.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/StandardAuthenticator.java
index 492253376..3e276046f 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/StandardAuthenticator.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/StandardAuthenticator.java
@@ -110,7 +110,7 @@ public class StandardAuthenticator implements HugeAuthenticator {
     public void setup(HugeConfig config) {
         String graphName = config.get(ServerOptions.AUTH_GRAPH_STORE);
         Map<String, String> graphConfs = ConfigUtil.scanGraphsDir(
-                                         config.get(ServerOptions.GRAPHS));
+                config.get(ServerOptions.GRAPHS));
         String graphPath = graphConfs.get(graphName);
         E.checkArgument(graphPath != null,
                         "Can't find graph name '%s' in config '%s' at " +
@@ -137,7 +137,7 @@ public class StandardAuthenticator implements HugeAuthenticator {
         String remoteUrl = config.get(ServerOptions.AUTH_REMOTE_URL);
         if (StringUtils.isNotEmpty(remoteUrl)) {
             RpcClientProviderWithAuth clientProvider =
-                                      new RpcClientProviderWithAuth(config);
+                    new RpcClientProviderWithAuth(config);
             this.graph.switchAuthManager(clientProvider.authManager());
         }
     }
@@ -159,9 +159,10 @@ public class StandardAuthenticator implements HugeAuthenticator {
 
     /**
      * Verify if a user is legal
+     *
      * @param username the username for authentication
      * @param password the password for authentication
-     * @param token the token for authentication
+     * @param token    the token for authentication
      * @return String No permission if return ROLE_NONE else return a role
      */
     @Override
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/WsAndHttpBasicAuthHandler.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/WsAndHttpBasicAuthHandler.java
index 205074ae7..1b329e19f 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/WsAndHttpBasicAuthHandler.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/auth/WsAndHttpBasicAuthHandler.java
@@ -24,7 +24,7 @@ import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
 import static org.apache.tinkerpop.gremlin.groovy.jsr223.dsl.credential.CredentialGraphTokens.PROPERTY_PASSWORD;
 import static org.apache.tinkerpop.gremlin.groovy.jsr223.dsl.credential.CredentialGraphTokens.PROPERTY_USERNAME;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.HashMap;
 import java.util.Map;
@@ -61,7 +61,7 @@ public class WsAndHttpBasicAuthHandler extends SaslAuthenticationHandler {
 
     @Override
     public void channelRead(final ChannelHandlerContext ctx, final Object obj)
-                            throws Exception {
+            throws Exception {
         if (obj instanceof HttpMessage && !isWebSocket((HttpMessage) obj)) {
             ChannelPipeline pipeline = ctx.pipeline();
             ChannelHandler authHandler = pipeline.get(HTTP_AUTH);
@@ -86,7 +86,7 @@ public class WsAndHttpBasicAuthHandler extends SaslAuthenticationHandler {
 
     @ChannelHandler.Sharable
     private static class HttpBasicAuthHandler
-                   extends AbstractAuthenticationHandler {
+            extends AbstractAuthenticationHandler {
 
         private final Base64.Decoder decoder = Base64.getUrlDecoder();
 
@@ -122,7 +122,7 @@ public class WsAndHttpBasicAuthHandler extends SaslAuthenticationHandler {
                     return;
                 }
                 String authorization = new String(userPass,
-                                                  Charset.forName("UTF-8"));
+                                                  StandardCharsets.UTF_8);
                 String[] split = authorization.split(":");
                 if (split.length != 2) {
                     sendError(ctx, msg);
@@ -134,7 +134,7 @@ public class WsAndHttpBasicAuthHandler extends SaslAuthenticationHandler {
                     address = address.substring(1);
                 }
 
-                final Map<String,String> credentials = new HashMap<>();
+                final Map<String, String> credentials = new HashMap<>();
                 credentials.put(PROPERTY_USERNAME, split[0]);
                 credentials.put(PROPERTY_PASSWORD, split[1]);
                 credentials.put(HugeAuthenticator.KEY_ADDRESS, address);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/config/ServerOptions.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/config/ServerOptions.java
index e18d5139a..b46735c8f 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/config/ServerOptions.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/config/ServerOptions.java
@@ -274,36 +274,36 @@ public class ServerOptions extends OptionHolder {
             );
 
     public static final ConfigOption<String> ARTHAS_TELNET_PORT =
-        new ConfigOption<>(
-            "arthas.telnet_port",
-            "The telnet port provided by Arthas, it can be accessible from the outside.",
-            disallowEmpty(),
-            "8562"
-        );
+            new ConfigOption<>(
+                    "arthas.telnet_port",
+                    "The telnet port provided by Arthas, it can be accessible from the outside.",
+                    disallowEmpty(),
+                    "8562"
+            );
 
     public static final ConfigOption<String> ARTHAS_HTTP_PORT =
-        new ConfigOption<>(
-            "arthas.http_port",
-            "The HTTP port provided by Arthas, it can be accessible from the outside.",
-            disallowEmpty(),
-            "8561"
-        );
+            new ConfigOption<>(
+                    "arthas.http_port",
+                    "The HTTP port provided by Arthas, it can be accessible from the outside.",
+                    disallowEmpty(),
+                    "8561"
+            );
 
     public static final ConfigOption<String> ARTHAS_IP =
-        new ConfigOption<>(
-            "arthas.ip",
-            "The IP provided by Arthas, it can be accessible from the outside.",
-            disallowEmpty(),
-            "0.0.0.0"
-        );
+            new ConfigOption<>(
+                    "arthas.ip",
+                    "The IP provided by Arthas, it can be accessible from the outside.",
+                    disallowEmpty(),
+                    "0.0.0.0"
+            );
 
     public static final ConfigOption<String> ARTHAS_DISABLED_COMMANDS =
-        new ConfigOption<>(
-            "arthas.disabled_commands",
-            "The disabled Arthas commands due to high risk.",
-            null,
-            "jad"
-        );
+            new ConfigOption<>(
+                    "arthas.disabled_commands",
+                    "The disabled Arthas commands due to high risk.",
+                    null,
+                    "jad"
+            );
 
     public static final ConfigOption<Long> SLOW_QUERY_LOG_TIME_THRESHOLD =
             new ConfigOption<>(
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/core/GraphManager.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/core/GraphManager.java
index 9b3c3a10a..1830d81c7 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/core/GraphManager.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/core/GraphManager.java
@@ -158,7 +158,7 @@ public final class GraphManager {
         HugeConfig cloneConfig = cloneGraph.cloneConfig(newName);
         if (StringUtils.isNotEmpty(configText)) {
             PropertiesConfiguration propConfig = ConfigUtil.buildConfig(
-                                                 configText);
+                    configText);
             // Use the passed config to overwrite the old one
             propConfig.getKeys().forEachRemaining(key -> {
                 cloneConfig.setProperty(key, propConfig.getProperty(key));
@@ -259,7 +259,7 @@ public final class GraphManager {
     }
 
     public HugeAuthenticator.User authenticate(Map<String, String> credentials)
-                                               throws AuthenticationException {
+            throws AuthenticationException {
         return this.authenticator().authenticate(credentials);
     }
 
@@ -436,20 +436,20 @@ public final class GraphManager {
                         this.authenticator().initAdminUser(token);
                     } catch (Exception e) {
                         throw new BackendException(
-                                  "The backend store of '%s' can't " +
-                                  "initialize admin user", hugegraph.name());
+                                "The backend store of '%s' can't " +
+                                "initialize admin user", hugegraph.name());
                     }
                 }
             }
             BackendStoreInfo info = hugegraph.backendStoreInfo();
             if (!info.exists()) {
                 throw new BackendException(
-                          "The backend store of '%s' has not been initialized",
-                          hugegraph.name());
+                        "The backend store of '%s' has not been initialized",
+                        hugegraph.name());
             }
             if (!info.checkVersion()) {
                 throw new BackendException(
-                          "The backend store version is inconsistent");
+                        "The backend store version is inconsistent");
             }
         }
     }
@@ -521,7 +521,7 @@ public final class GraphManager {
         });
 
         // Add metrics for caches
-        @SuppressWarnings({ "rawtypes", "unchecked" })
+        @SuppressWarnings({"rawtypes", "unchecked"})
         Map<String, Cache<?, ?>> caches = (Map) CacheManager.instance()
                                                             .caches();
         registerCacheMetrics(caches);
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/define/UpdateStrategy.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/define/UpdateStrategy.java
index c910dc8c2..887bf7d45 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/define/UpdateStrategy.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/define/UpdateStrategy.java
@@ -26,6 +26,7 @@ import java.util.Set;
 
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.NumericUtil;
+
 import com.google.common.collect.Sets;
 
 public enum UpdateStrategy {
@@ -113,7 +114,7 @@ public enum UpdateStrategy {
     // Batch update Set should use union because of higher efficiency
     APPEND {
         @Override
-        @SuppressWarnings({ "rawtypes", "unchecked" })
+        @SuppressWarnings({"rawtypes", "unchecked"})
         Object updatePropertyValue(Object oldProperty, Object newProperty) {
             ((Collection) oldProperty).addAll((Collection) newProperty);
             return oldProperty;
@@ -127,7 +128,7 @@ public enum UpdateStrategy {
 
     ELIMINATE {
         @Override
-        @SuppressWarnings({ "rawtypes", "unchecked" })
+        @SuppressWarnings({"rawtypes", "unchecked"})
         Object updatePropertyValue(Object oldProperty, Object newProperty) {
             ((Collection) oldProperty).removeAll((Collection) newProperty);
             return oldProperty;
@@ -186,7 +187,7 @@ public enum UpdateStrategy {
         Number newNum = NumericUtil.convertToNumber(newProperty);
         int result = NumericUtil.compareNumber(oldNum, newNum);
         return strategy == BIGGER ? (result > 0 ? oldProperty : newProperty) :
-                                    (result < 0 ? oldProperty : newProperty);
+               (result < 0 ? oldProperty : newProperty);
     }
 
     protected static Set<?> combineSet(Object oldProperty, Object newProperty,
@@ -198,6 +199,6 @@ public enum UpdateStrategy {
                         (Set<?>) newProperty :
                         new HashSet<>((List<?>) newProperty);
         return strategy == UNION ? Sets.union(oldSet, newSet) :
-                                   Sets.intersection(oldSet, newSet);
+               Sets.intersection(oldSet, newSet);
     }
 }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/MetricsModule.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/MetricsModule.java
index 5107b4611..0d42b6369 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/MetricsModule.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/MetricsModule.java
@@ -227,7 +227,7 @@ public class MetricsModule extends Module {
     }
 
     private static class MetricRegistrySerializer
-                   extends StdSerializer<MetricRegistry> {
+            extends StdSerializer<MetricRegistry> {
 
         private static final long serialVersionUID = 3717001164181726933L;
 
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/ServerReporter.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/ServerReporter.java
index d3cd6855b..b302ddc5d 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/ServerReporter.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/ServerReporter.java
@@ -26,6 +26,7 @@ import java.util.SortedMap;
 import java.util.concurrent.TimeUnit;
 
 import org.apache.hugegraph.util.E;
+
 import com.codahale.metrics.Counter;
 import com.codahale.metrics.Gauge;
 import com.codahale.metrics.Histogram;
@@ -47,7 +48,7 @@ public class ServerReporter extends ScheduledReporter {
     private SortedMap<String, Timer> timers;
 
     public static synchronized ServerReporter instance(
-                                              MetricRegistry registry) {
+            MetricRegistry registry) {
         if (instance == null) {
             synchronized (ServerReporter.class) {
                 if (instance == null) {
@@ -97,7 +98,7 @@ public class ServerReporter extends ScheduledReporter {
         return Collections.unmodifiableMap(this.meters);
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     @Override
     public void report(SortedMap<String, Gauge> gauges,
                        SortedMap<String, Counter> counters,
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/SystemMetrics.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/SystemMetrics.java
index 903ac6103..3aeaca344 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/SystemMetrics.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/metrics/SystemMetrics.java
@@ -27,7 +27,6 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.commons.lang3.StringUtils;
-
 import org.apache.hugegraph.util.Bytes;
 
 public class SystemMetrics {
@@ -112,7 +111,7 @@ public class SystemMetrics {
     private Map<String, Object> getClassLoadingMetrics() {
         Map<String, Object> metrics = new LinkedHashMap<>();
         ClassLoadingMXBean classLoadingMxBean = ManagementFactory
-                                                .getClassLoadingMXBean();
+                .getClassLoadingMXBean();
         metrics.put("count", classLoadingMxBean.getLoadedClassCount());
         metrics.put("loaded", classLoadingMxBean.getTotalLoadedClassCount());
         metrics.put("unloaded", classLoadingMxBean.getUnloadedClassCount());
@@ -122,7 +121,7 @@ public class SystemMetrics {
     private Map<String, Object> getGarbageCollectionMetrics() {
         Map<String, Object> metrics = new LinkedHashMap<>();
         List<GarbageCollectorMXBean> gcMxBeans = ManagementFactory
-                                                 .getGarbageCollectorMXBeans();
+                .getGarbageCollectorMXBeans();
         for (GarbageCollectorMXBean gcMxBean : gcMxBeans) {
             String name = formatName(gcMxBean.getName());
             metrics.put(name + "_count", gcMxBean.getCollectionCount());
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherOpProcessor.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherOpProcessor.java
index a4dfff60a..dfad9b959 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherOpProcessor.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherOpProcessor.java
@@ -16,7 +16,22 @@
 
 package org.apache.hugegraph.opencypher;
 
-import io.netty.channel.ChannelHandlerContext;
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.singletonList;
+import static java.util.Optional.empty;
+import static org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode.SERVER_ERROR;
+import static org.opencypher.gremlin.translation.StatementOption.EXPLAIN;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.Future;
+import java.util.concurrent.FutureTask;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.tinkerpop.gremlin.driver.Tokens;
 import org.apache.tinkerpop.gremlin.driver.message.RequestMessage;
@@ -45,20 +60,9 @@ import org.opencypher.gremlin.traversal.ProcedureContext;
 import org.opencypher.gremlin.traversal.ReturnNormalizer;
 import org.slf4j.Logger;
 
+import io.netty.channel.ChannelHandlerContext;
 import scala.collection.Seq;
 
-import java.util.*;
-import java.util.concurrent.Future;
-import java.util.concurrent.FutureTask;
-import java.util.concurrent.TimeUnit;
-
-import static java.util.Collections.emptyMap;
-import static java.util.Collections.singletonList;
-import static java.util.Optional.empty;
-import static org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode.SERVER_ERROR;
-import static org.opencypher.gremlin.translation.StatementOption.EXPLAIN;
-import static org.slf4j.LoggerFactory.getLogger;
-
 /**
  * Description of the modifications:
  * <p>
@@ -80,7 +84,7 @@ import static org.slf4j.LoggerFactory.getLogger;
  * <p>
  * 3) Set the logger level from info to trace
  * </p>
- *
+ * <p>
  * {@link OpProcessor} implementation for processing Cypher {@link RequestMessage}s:
  * <pre>
  * {
@@ -94,7 +98,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 public class CypherOpProcessor extends AbstractEvalOpProcessor {
 
     private static final String DEFAULT_TRANSLATOR_DEFINITION =
-        "gremlin+cfog_server_extensions+inline_parameters";
+            "gremlin+cfog_server_extensions+inline_parameters";
 
     private static final Logger logger = getLogger(CypherOpProcessor.class);
 
@@ -242,8 +246,8 @@ public class CypherOpProcessor extends AbstractEvalOpProcessor {
                                                  .getExecutorService().submit(evalFuture);
         if (timeout > 0) {
             context.getScheduledExecutorService().schedule(
-                () -> executionFuture.cancel(true)
-                , timeout, TimeUnit.MILLISECONDS);
+                    () -> executionFuture.cancel(true)
+                    , timeout, TimeUnit.MILLISECONDS);
         }
 
     }
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherPlugin.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherPlugin.java
index 98cf98eee..6d7899dd1 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherPlugin.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/opencypher/CypherPlugin.java
@@ -28,13 +28,6 @@
 
 package org.apache.hugegraph.opencypher;
 
-import org.apache.tinkerpop.gremlin.jsr223.Customizer;
-import org.apache.tinkerpop.gremlin.jsr223.DefaultImportCustomizer;
-import org.apache.tinkerpop.gremlin.jsr223.GremlinPlugin;
-import org.apache.tinkerpop.gremlin.jsr223.ImportCustomizer;
-import org.opencypher.gremlin.traversal.CustomFunctions;
-import org.opencypher.gremlin.traversal.CustomPredicate;
-
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.List;
@@ -42,15 +35,24 @@ import java.util.Optional;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.apache.tinkerpop.gremlin.jsr223.Customizer;
+import org.apache.tinkerpop.gremlin.jsr223.DefaultImportCustomizer;
+import org.apache.tinkerpop.gremlin.jsr223.GremlinPlugin;
+import org.apache.tinkerpop.gremlin.jsr223.ImportCustomizer;
+import org.opencypher.gremlin.traversal.CustomFunctions;
+import org.opencypher.gremlin.traversal.CustomPredicate;
+
 public class CypherPlugin implements GremlinPlugin {
 
     private static final ImportCustomizer IMPORTS =
-        DefaultImportCustomizer.build()
-                               .addClassImports(CustomPredicate.class)
-                               .addMethodImports(getDeclaredPublicMethods(CustomPredicate.class))
-                               .addClassImports(CustomFunctions.class)
-                               .addMethodImports(getDeclaredPublicMethods(CustomFunctions.class))
-                               .create();
+            DefaultImportCustomizer.build()
+                                   .addClassImports(CustomPredicate.class)
+                                   .addMethodImports(
+                                           getDeclaredPublicMethods(CustomPredicate.class))
+                                   .addClassImports(CustomFunctions.class)
+                                   .addMethodImports(
+                                           getDeclaredPublicMethods(CustomFunctions.class))
+                                   .create();
 
     private static List<Method> getDeclaredPublicMethods(Class<?> klass) {
         Method[] declaredMethods = klass.getDeclaredMethods();
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/rpc/RpcClientProviderWithAuth.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/rpc/RpcClientProviderWithAuth.java
index 1311e3e32..80af0ab36 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/rpc/RpcClientProviderWithAuth.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/rpc/RpcClientProviderWithAuth.java
@@ -17,12 +17,13 @@
 
 package org.apache.hugegraph.rpc;
 
-import com.alipay.sofa.rpc.common.utils.StringUtils;
 import org.apache.hugegraph.auth.AuthManager;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.config.ServerOptions;
 import org.apache.hugegraph.util.E;
 
+import com.alipay.sofa.rpc.common.utils.StringUtils;
+
 public class RpcClientProviderWithAuth extends RpcClientProvider {
 
     private final RpcConsumerConfig authConsumerConfig;
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/ApplicationConfig.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/ApplicationConfig.java
index e477fce1d..7784613f5 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/ApplicationConfig.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/ApplicationConfig.java
@@ -42,32 +42,32 @@ import com.codahale.metrics.jersey3.InstrumentedResourceMethodApplicationListene
 
 import io.swagger.v3.jaxrs2.integration.resources.OpenApiResource;
 import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;
 import io.swagger.v3.oas.annotations.info.Contact;
 import io.swagger.v3.oas.annotations.info.Info;
-import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.security.SecurityScheme;
 import jakarta.ws.rs.ApplicationPath;
 
 @SecurityScheme(
-    name = "basic",
-    type = SecuritySchemeType.HTTP,
-    scheme = "basic"
+        name = "basic",
+        type = SecuritySchemeType.HTTP,
+        scheme = "basic"
 )
 @SecurityScheme(
-    name = "bearer",
-    type = SecuritySchemeType.HTTP,
-    scheme = "bearer"
+        name = "bearer",
+        type = SecuritySchemeType.HTTP,
+        scheme = "bearer"
 )
 @ApplicationPath("/")
 @OpenAPIDefinition(
-    info = @Info(
-        title = "HugeGraph RESTful API",
-        version = CoreVersion.DEFAULT_VERSION,
-        description = "All management API for HugeGraph",
-        contact = @Contact(url = "https://github.com/apache/hugegraph", name = "HugeGraph")
-    ),
-    security = {@SecurityRequirement(name = "basic"), @SecurityRequirement(name = "bearer")}
+        info = @Info(
+                title = "HugeGraph RESTful API",
+                version = CoreVersion.DEFAULT_VERSION,
+                description = "All management API for HugeGraph",
+                contact = @Contact(url = "https://github.com/apache/hugegraph", name = "HugeGraph")
+        ),
+        security = {@SecurityRequirement(name = "basic"), @SecurityRequirement(name = "bearer")}
 )
 public class ApplicationConfig extends ResourceConfig {
 
@@ -131,9 +131,9 @@ public class ApplicationConfig extends ResourceConfig {
         public GraphManagerFactory(HugeConfig conf, EventHub hub) {
             register(new ApplicationEventListener() {
                 private final ApplicationEvent.Type eventInited =
-                              ApplicationEvent.Type.INITIALIZATION_FINISHED;
+                        ApplicationEvent.Type.INITIALIZATION_FINISHED;
                 private final ApplicationEvent.Type eventDestroyed =
-                              ApplicationEvent.Type.DESTROY_FINISHED;
+                        ApplicationEvent.Type.DESTROY_FINISHED;
 
                 @Override
                 public void onEvent(ApplicationEvent event) {
diff --git a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/RestServer.java b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/RestServer.java
index 01ce8da94..90e4e19f4 100644
--- a/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/RestServer.java
+++ b/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/server/RestServer.java
@@ -23,8 +23,12 @@ import java.util.Collection;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 
-import jakarta.ws.rs.core.UriBuilder;
-
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.config.ServerOptions;
+import org.apache.hugegraph.event.EventHub;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
+import org.apache.hugegraph.version.ApiVersion;
 import org.glassfish.grizzly.CompletionHandler;
 import org.glassfish.grizzly.GrizzlyFuture;
 import org.glassfish.grizzly.http.server.HttpServer;
@@ -36,12 +40,7 @@ import org.glassfish.jersey.grizzly2.httpserver.GrizzlyHttpServerFactory;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.config.ServerOptions;
-import org.apache.hugegraph.event.EventHub;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
-import org.apache.hugegraph.version.ApiVersion;
+import jakarta.ws.rs.core.UriBuilder;
 
 public class RestServer {
 
@@ -82,13 +81,13 @@ public class RestServer {
         if (protocol != null && protocol.equals("https")) {
             SSLContextConfigurator sslContext = new SSLContextConfigurator();
             String keystoreFile = this.conf.get(
-                                  ServerOptions.SSL_KEYSTORE_FILE);
+                    ServerOptions.SSL_KEYSTORE_FILE);
             String keystorePass = this.conf.get(
-                                  ServerOptions.SSL_KEYSTORE_PASSWORD);
+                    ServerOptions.SSL_KEYSTORE_PASSWORD);
             sslContext.setKeyStoreFile(keystoreFile);
             sslContext.setKeyStorePass(keystorePass);
             SSLEngineConfigurator sslConfig = new SSLEngineConfigurator(
-                                              sslContext);
+                    sslContext);
             sslConfig.setClientMode(false);
             sslConfig.setWantClientAuth(true);
             server = GrizzlyHttpServerFactory.createHttpServer(uri, rc, true,
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraEntryIterator.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraEntryIterator.java
index 8cb0bc78b..2f057007f 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraEntryIterator.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraEntryIterator.java
@@ -43,7 +43,7 @@ public class CassandraEntryIterator extends BackendEntryIterator {
     private BackendEntry next;
 
     public CassandraEntryIterator(ResultSet results, Query query,
-           BiFunction<BackendEntry, Row, BackendEntry> merger) {
+                                  BiFunction<BackendEntry, Row, BackendEntry> merger) {
         super(query);
         this.results = results;
         this.rows = results.iterator();
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraMetrics.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraMetrics.java
index e3e3eb51a..400efd024 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraMetrics.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraMetrics.java
@@ -108,7 +108,7 @@ public class CassandraMetrics implements BackendMetrics {
             metrics.put(MEM_UNIT, "MB");
 
             long diskSize = UnitUtil.bytesFromReadableString(
-                            probe.getLoadString());
+                    probe.getLoadString());
             metrics.put(DISK_USAGE, UnitUtil.bytesToGB(diskSize));
             metrics.put(DISK_USAGE + READABLE,
                         UnitUtil.bytesToReadableString(diskSize));
@@ -213,7 +213,7 @@ public class CassandraMetrics implements BackendMetrics {
         String name = humpToLine(metric + "_" + suffix);
         // Aggregation of metrics for the whole host if keyspace=null
         JmxTimerMBean value = (JmxTimerMBean) probe.getColumnFamilyMetric(
-                              keyspace, null, metric);
+                keyspace, null, metric);
         Map<String, Object> timerMap = InsertionOrderUtil.newMap();
         timerMap.put("count", value.getCount());
         timerMap.put("min", value.getMin());
@@ -316,7 +316,7 @@ public class CassandraMetrics implements BackendMetrics {
     }
 
     private NodeProbe newNodeProbe(String host) throws IOException {
-        LOG.debug("Probe to cassandra node: '{}:{}'", host,  this.port);
+        LOG.debug("Probe to cassandra node: '{}:{}'", host, this.port);
         return this.username.isEmpty() ?
                new NodeProbe(host, this.port) :
                new NodeProbe(host, this.port, this.username, this.password);
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSerializer.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSerializer.java
index 0901a0231..fc3c499a8 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSerializer.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSerializer.java
@@ -45,6 +45,7 @@ import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.JsonUtil;
+
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSessionPool.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSessionPool.java
index a50cc3099..7a9ffa2b9 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSessionPool.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraSessionPool.java
@@ -26,6 +26,7 @@ import org.apache.hugegraph.backend.store.BackendSession.AbstractBackendSession;
 import org.apache.hugegraph.backend.store.BackendSessionPool;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.E;
+
 import com.datastax.driver.core.BatchStatement;
 import com.datastax.driver.core.Cluster;
 import com.datastax.driver.core.Cluster.Builder;
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraShard.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraShard.java
index 30bd14834..5f3792298 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraShard.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraShard.java
@@ -32,7 +32,6 @@ import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
-import org.apache.cassandra.schema.SchemaConstants;
 import org.apache.cassandra.db.SystemKeyspace;
 import org.apache.cassandra.dht.ByteOrderedPartitioner;
 import org.apache.cassandra.dht.IPartitioner;
@@ -41,10 +40,11 @@ import org.apache.cassandra.dht.OrderPreservingPartitioner;
 import org.apache.cassandra.dht.Range;
 import org.apache.cassandra.dht.Token;
 import org.apache.cassandra.dht.Token.TokenFactory;
-
+import org.apache.cassandra.schema.SchemaConstants;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.Shard;
 import org.apache.hugegraph.util.Bytes;
+
 import com.datastax.driver.core.Host;
 import com.datastax.driver.core.Metadata;
 import com.datastax.driver.core.ResultSet;
@@ -82,9 +82,10 @@ public class CassandraShard {
 
     /**
      * Get splits of a table
+     *
      * @param splitPartitions: expected partitions count per split
-     * @param splitSize: expected size(bytes) per split,
-     *        splitPartitions will be ignored if splitSize is passed
+     * @param splitSize:       expected size(bytes) per split,
+     *                         splitPartitions will be ignored if splitSize is passed
      * @return a list of Shard
      */
     public List<Shard> getSplits(long splitPartitions, long splitSize) {
@@ -105,7 +106,7 @@ public class CassandraShard {
                  * compute bite-sized splits.
                  */
                 futures.add(executor.submit(new SplitCallable(
-                            range, splitPartitions, splitSize)));
+                        range, splitPartitions, splitSize)));
             }
 
             // Wait until we have all the results back
@@ -128,11 +129,12 @@ public class CassandraShard {
     /**
      * Get splits of a table in specified range
      * NOTE: maybe we don't need this method
-     * @param start: the start of range
-     * @param end: the end of range
+     *
+     * @param start:           the start of range
+     * @param end:             the end of range
      * @param splitPartitions: expected partitions count per split
-     * @param splitSize: expected size(bytes) per split,
-     *        splitPartitions will be ignored if splitSize is passed
+     * @param splitSize:       expected size(bytes) per split,
+     *                         splitPartitions will be ignored if splitSize is passed
      * @return a list of Shard
      */
     public List<Shard> getSplits(String start, String end,
@@ -146,8 +148,8 @@ public class CassandraShard {
             List<Future<List<Shard>>> futures = new ArrayList<>();
             TokenFactory tokenFactory = this.partitioner.getTokenFactory();
             TokenRange tokenRange = rangeToTokenRange(new Range<>(
-                                    tokenFactory.fromString(start),
-                                    tokenFactory.fromString(end)));
+                    tokenFactory.fromString(start),
+                    tokenFactory.fromString(end)));
 
             // Canonical ranges and nodes holding replicas
             Map<TokenRange, Set<Host>> masterRangeNodes = getRangeMap();
@@ -157,7 +159,7 @@ public class CassandraShard {
                     // For each tokenRange, pick a live owner and ask it
                     // to compute bite-sized splits
                     futures.add(executor.submit(new SplitCallable(
-                                r, splitPartitions, splitSize)));
+                            r, splitPartitions, splitSize)));
                 }
             }
 
@@ -187,8 +189,8 @@ public class CassandraShard {
         TokenFactory tokenFactory = this.partitioner.getTokenFactory();
         Metadata metadata = this.session.metadata();
         return metadata.newTokenRange(
-                        metadata.newToken(tokenFactory.toString(range.left)),
-                        metadata.newToken(tokenFactory.toString(range.right)));
+                metadata.newToken(tokenFactory.toString(range.left)),
+                metadata.newToken(tokenFactory.toString(range.right)));
     }
 
     private Map<TokenRange, Long> getSubSplits(TokenRange tokenRange,
@@ -205,8 +207,8 @@ public class CassandraShard {
     private Map<TokenRange, Set<Host>> getRangeMap() {
         Metadata metadata = this.session.metadata();
         return metadata.getTokenRanges().stream().collect(Collectors.toMap(
-            p -> p,
-            p -> metadata.getReplicas('"' + this.keyspace + '"', p)));
+                p -> p,
+                p -> metadata.getReplicas('"' + this.keyspace + '"', p)));
     }
 
     private static Map<TokenRange, Long> describeSplits(
@@ -274,15 +276,15 @@ public class CassandraShard {
                              long splitPartitions, long splitSize) {
             if (splitSize <= 0 && splitPartitions <= 0) {
                 throw new IllegalArgumentException(String.format(
-                          "The split-partitions must be > 0, but got %s",
-                          splitPartitions));
+                        "The split-partitions must be > 0, but got %s",
+                        splitPartitions));
             }
 
             if (splitSize > 0 && splitSize < MIN_SHARD_SIZE) {
                 // splitSize should be at least 1M if passed
                 throw new IllegalArgumentException(String.format(
-                          "The split-size must be >= %s bytes, but got %s",
-                          MIN_SHARD_SIZE, splitSize));
+                        "The split-size must be >= %s bytes, but got %s",
+                        MIN_SHARD_SIZE, splitSize));
             }
 
             this.tokenRange = tokenRange;
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraStore.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraStore.java
index 31038652b..838a44078 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraStore.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraStore.java
@@ -26,8 +26,6 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
@@ -45,6 +43,7 @@ import org.apache.hugegraph.exception.ConnectionException;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 import com.datastax.driver.core.Cluster;
 import com.datastax.driver.core.KeyspaceMetadata;
@@ -169,13 +168,13 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
                 this.sessions.session().open();
             } catch (InvalidQueryException e) {
                 // TODO: the error message may be changed in different versions
-                if (!e.getMessage().contains(String.format(
-                    "Keyspace '%s' does not exist", this.keyspace))) {
+                if (!e.getMessage().contains(String.format("Keyspace '%s' does not exist",
+                                                           this.keyspace))) {
                     throw e;
                 }
                 if (this.isSchemaStore()) {
-                    LOG.info("Failed to connect keyspace: {}, " +
-                             "try to init keyspace later", this.keyspace);
+                    LOG.info("Failed to connect keyspace: {}, try to init keyspace later",
+                             this.keyspace);
                 }
             }
         } catch (Throwable e) {
@@ -211,13 +210,12 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
         this.checkOpened();
         CassandraSessionPool.Session session = this.sessions.session();
 
-        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext();) {
+        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext(); ) {
             this.mutate(session, it.next());
         }
     }
 
-    private void mutate(CassandraSessionPool.Session session,
-                        BackendAction item) {
+    private void mutate(CassandraSessionPool.Session session, BackendAction item) {
         CassandraBackendEntry entry = castBackendEntry(item.entry());
 
         // Check if the entry has no change
@@ -296,7 +294,7 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported mutate action: %s", item.action()));
+                        "Unsupported mutate action: %s", item.action()));
         }
     }
 
@@ -305,7 +303,7 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
         this.checkOpened();
         HugeType type = CassandraTable.tableType(query);
         String tableName = query.olap() ? this.olapTableName(type) :
-                                          type.string();
+                           type.string();
         CassandraTable table = this.table(tableName);
         Iterator<BackendEntry> entries = table.query(this.session(null), query);
         // Merge olap results as needed
@@ -443,11 +441,11 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
         } catch (DriverException e) {
             session.txState(TxState.COMMITT_FAIL);
             LOG.error("Failed to commit statements due to:", e);
-            assert session.statements().size() > 0;
+            assert !session.statements().isEmpty();
             throw new BackendException(
-                      "Failed to commit %s statements: '%s'...", e,
-                      session.statements().size(),
-                      session.statements().iterator().next());
+                    "Failed to commit %s statements: '%s'...", e,
+                    session.statements().size(),
+                    session.statements().iterator().next());
         }
     }
 
@@ -512,7 +510,7 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
         switch (strategy) {
             case "SimpleStrategy":
                 List<String> replicas =
-                             conf.get(CassandraOptions.CASSANDRA_REPLICATION);
+                        conf.get(CassandraOptions.CASSANDRA_REPLICATION);
                 E.checkArgument(replicas.size() == 1,
                                 "Individual factor value should be provided " +
                                 "with SimpleStrategy for Cassandra");
@@ -522,7 +520,7 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
             case "NetworkTopologyStrategy":
                 // The replicas format is like 'dc1:2,dc2:1'
                 Map<String, String> replicaMap =
-                            conf.getMap(CassandraOptions.CASSANDRA_REPLICATION);
+                        conf.getMap(CassandraOptions.CASSANDRA_REPLICATION);
                 for (Map.Entry<String, String> e : replicaMap.entrySet()) {
                     E.checkArgument(!e.getKey().isEmpty(),
                                     "The datacenter can't be empty");
@@ -531,9 +529,9 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Illegal replication strategy '%s', valid strategy " +
-                          "is 'SimpleStrategy' or 'NetworkTopologyStrategy'",
-                          strategy));
+                        "Illegal replication strategy '%s', valid strategy " +
+                        "is 'SimpleStrategy' or 'NetworkTopologyStrategy'",
+                        strategy));
         }
         return replication;
     }
@@ -543,8 +541,8 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
             return Integer.valueOf(factor);
         } catch (NumberFormatException e) {
             throw new BackendException(
-                      "Expect int factor value for SimpleStrategy, " +
-                      "but got '%s'", factor);
+                    "Expect int factor value for SimpleStrategy, " +
+                    "but got '%s'", factor);
         }
     }
 
@@ -720,19 +718,19 @@ public abstract class CassandraStore extends AbstractBackendStore<CassandraSessi
         @Override
         public Id nextId(HugeType type) {
             throw new UnsupportedOperationException(
-                      "CassandraGraphStore.nextId()");
+                    "CassandraGraphStore.nextId()");
         }
 
         @Override
         public void increaseCounter(HugeType type, long num) {
             throw new UnsupportedOperationException(
-                      "CassandraGraphStore.increaseCounter()");
+                    "CassandraGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "CassandraGraphStore.getCounter()");
+                    "CassandraGraphStore.getCounter()");
         }
 
         @Override
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTable.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTable.java
index 633c98bc8..15ad1a7bd 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTable.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTable.java
@@ -27,9 +27,6 @@ import java.util.Set;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.page.PageState;
@@ -51,6 +48,9 @@ import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.CopyUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
+import org.slf4j.Logger;
+
 import com.datastax.driver.core.ColumnDefinitions.Definition;
 import com.datastax.driver.core.DataType;
 import com.datastax.driver.core.PagingState;
@@ -74,7 +74,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
 public abstract class CassandraTable
-                extends BackendTable<CassandraSessionPool.Session, CassandraBackendEntry.Row> {
+        extends BackendTable<CassandraSessionPool.Session, CassandraBackendEntry.Row> {
 
     private static final Logger LOG = Log.logger(CassandraTable.class);
     private static final int MAX_ELEMENTS_IN_CLAUSE = 65535;
@@ -90,8 +90,8 @@ public abstract class CassandraTable
                             "The args count of %s must be 1", meta);
             long splitSize = (long) args[0];
             CassandraShard splitter = new CassandraShard(session,
-                                                        session.keyspace(),
-                                                        this.table());
+                                                         session.keyspace(),
+                                                         this.table());
             return splitter.getSplits(0, splitSize);
         });
     }
@@ -118,12 +118,12 @@ public abstract class CassandraTable
             statement.setReadTimeoutMillis(timeout * 1000);
             return session.query(statement);
         }, (q, rs) -> {
-                Row row = rs.one();
-                if (row == null) {
-                    return IteratorUtils.of(aggregate.defaultValue());
-                }
-                return IteratorUtils.of(row.getLong(0));
-            });
+            Row row = rs.one();
+            if (row == null) {
+                return IteratorUtils.of(aggregate.defaultValue());
+            }
+            return IteratorUtils.of(row.getLong(0));
+        });
         return aggregate.reduce(results);
     }
 
@@ -135,8 +135,7 @@ public abstract class CassandraTable
 
     protected <R> Iterator<R> query(Query query,
                                     Function<Statement, ResultSet> fetcher,
-                                    BiFunction<Query, ResultSet, Iterator<R>>
-                                    parser) {
+                                    BiFunction<Query, ResultSet, Iterator<R>> parser) {
         ExtendableIterator<R> rs = new ExtendableIterator<>();
 
         if (query.limit() == 0L && !query.noLimit()) {
@@ -279,8 +278,8 @@ public abstract class CassandraTable
             List<Object> idParts = this.idColumnValue(id);
             if (nameParts.size() != idParts.size()) {
                 throw new NotFoundException(
-                          "Unsupported ID format: '%s' (should contain %s)",
-                          id, nameParts);
+                        "Unsupported ID format: '%s' (should contain %s)",
+                        id, nameParts);
             }
             ids.add(idParts);
         }
@@ -373,7 +372,7 @@ public abstract class CassandraTable
                 return QueryBuilder.containsKey(key, value);
             case SCAN:
                 String[] col = pkColumnName().stream()
-                                             .map(pk -> formatKey(pk))
+                                             .map(CassandraTable::formatKey)
                                              .toArray(String[]::new);
                 Shard shard = (Shard) value;
                 Object start = QueryBuilder.raw(shard.start());
@@ -510,7 +509,7 @@ public abstract class CassandraTable
     }
 
     protected Insert buildInsert(CassandraBackendEntry.Row entry) {
-        assert entry.columns().size() > 0;
+        assert !entry.columns().isEmpty();
         Insert insert = QueryBuilder.insertInto(this.table());
 
         for (Map.Entry<HugeKeys, Object> c : entry.columns().entrySet()) {
diff --git a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTables.java b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTables.java
index 1b9b8509c..5f7490cb1 100644
--- a/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTables.java
+++ b/hugegraph-server/hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraTables.java
@@ -476,7 +476,7 @@ public class CassandraTables {
                 rs = session.execute(select);
             } catch (DriverException e) {
                 throw new BackendException("Failed to query edges " +
-                          "with label '%s' for deleting", e, label);
+                                           "with label '%s' for deleting", e, label);
             }
 
             // Delete edges
@@ -548,7 +548,7 @@ public class CassandraTables {
             E.checkState(ownerVertex != null, "Invalid backend entry");
             Id vertexId = IdGenerator.of(ownerVertex);
             CassandraBackendEntry vertex = new CassandraBackendEntry(
-                                               HugeType.VERTEX, vertexId);
+                    HugeType.VERTEX, vertexId);
 
             vertex.column(HugeKeys.ID, ownerVertex);
             vertex.column(HugeKeys.PROPERTIES, ImmutableMap.of());
@@ -635,8 +635,8 @@ public class CassandraTables {
                 rs = session.execute(select);
             } catch (DriverException e) {
                 throw new BackendException("Failed to query secondary " +
-                          "indexes with index label id '%s' for deleting",
-                          indexLabel, e);
+                                           "indexes with index label id '%s' for deleting",
+                                           indexLabel, e);
             }
 
             final String FIELD_VALUES = formatKey(HugeKeys.FIELD_VALUES);
diff --git a/hugegraph-server/hugegraph-dist/docker/README.md b/hugegraph-server/hugegraph-dist/docker/README.md
index 413ac7fd8..c47d66f8a 100644
--- a/hugegraph-server/hugegraph-dist/docker/README.md
+++ b/hugegraph-server/hugegraph-dist/docker/README.md
@@ -80,4 +80,4 @@ If you want to customize the pre-loaded data, please mount the the groovy script
         environment:
           - AUTH=true
           - PASSWORD=123456
-    ```
\ No newline at end of file
+    ```
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseMetrics.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseMetrics.java
index d593e7075..9a30c7aa7 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseMetrics.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseMetrics.java
@@ -29,11 +29,11 @@ import org.apache.hadoop.hbase.ServerMetrics;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.Size;
 import org.apache.hadoop.hbase.client.Admin;
-
 import org.apache.hugegraph.backend.store.BackendMetrics;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.UnitUtil;
+
 import com.google.common.collect.ImmutableMap;
 
 public class HbaseMetrics implements BackendMetrics {
@@ -55,7 +55,7 @@ public class HbaseMetrics implements BackendMetrics {
         try (Admin admin = this.hbase.hbase().getAdmin()) {
             ClusterMetrics clusterMetrics = admin.getClusterMetrics();
             Map<ServerName, ServerMetrics> metrics =
-                            clusterMetrics.getLiveServerMetrics();
+                    clusterMetrics.getLiveServerMetrics();
             Map<String, Object> regionServers = InsertionOrderUtil.newMap();
             for (Map.Entry<ServerName, ServerMetrics> e : metrics.entrySet()) {
                 ServerName server = e.getKey();
@@ -109,7 +109,7 @@ public class HbaseMetrics implements BackendMetrics {
     }
 
     private static Map<String, Object> formatMetrics(
-                                       ServerMetrics serverMetrics) {
+            ServerMetrics serverMetrics) {
         Map<String, Object> metrics = InsertionOrderUtil.newMap();
 
         Size memMax = serverMetrics.getMaxHeapSize();
@@ -144,7 +144,7 @@ public class HbaseMetrics implements BackendMetrics {
     }
 
     private static Map<String, Object> formatRegions(
-                                       Collection<RegionMetrics> regions) {
+            Collection<RegionMetrics> regions) {
         Map<String, Object> metrics = InsertionOrderUtil.newMap();
         for (RegionMetrics region : regions) {
             metrics.put(region.getNameAsString(), formatRegion(region));
@@ -193,7 +193,7 @@ public class HbaseMetrics implements BackendMetrics {
     }
 
     private static List<String> serversAddress(
-                                Collection<ServerName> servers) {
+            Collection<ServerName> servers) {
         return servers.stream().map(server -> {
             return server.getAddress().toString();
         }).collect(Collectors.toList());
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseOptions.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseOptions.java
index a88322933..60b6ba475 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseOptions.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseOptions.java
@@ -18,9 +18,9 @@
 package org.apache.hugegraph.backend.store.hbase;
 
 import static org.apache.hugegraph.config.OptionChecker.disallowEmpty;
+import static org.apache.hugegraph.config.OptionChecker.nonNegativeInt;
 import static org.apache.hugegraph.config.OptionChecker.positiveInt;
 import static org.apache.hugegraph.config.OptionChecker.rangeInt;
-import static org.apache.hugegraph.config.OptionChecker.nonNegativeInt;
 
 import org.apache.hugegraph.config.ConfigOption;
 import org.apache.hugegraph.config.OptionHolder;
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSerializer.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSerializer.java
index 9385a6130..5b528daf8 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSerializer.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSerializer.java
@@ -17,13 +17,14 @@
 
 package org.apache.hugegraph.backend.store.hbase;
 
+import java.util.Arrays;
+
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.serializer.BinarySerializer;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
-import java.util.Arrays;
 
 public class HbaseSerializer extends BinarySerializer {
 
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSessions.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSessions.java
index 6570efd7d..1b9c4afe7 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSessions.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseSessions.java
@@ -29,7 +29,6 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.Future;
-import org.apache.hugegraph.util.Log;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
@@ -68,8 +67,6 @@ import org.apache.hadoop.hbase.filter.PageFilter;
 import org.apache.hadoop.hbase.filter.PrefixFilter;
 import org.apache.hadoop.hbase.util.VersionInfo;
 import org.apache.hadoop.security.UserGroupInformation;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
 import org.apache.hugegraph.backend.store.BackendEntry.BackendIterator;
@@ -79,8 +76,11 @@ import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.exception.NotSupportException;
 import org.apache.hugegraph.util.Bytes;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.StringEncoding;
 import org.apache.hugegraph.util.VersionUtil;
+import org.slf4j.Logger;
+
 import com.google.common.util.concurrent.Futures;
 
 public class HbaseSessions extends BackendSessionPool {
@@ -218,7 +218,7 @@ public class HbaseSessions extends BackendSessionPool {
 
     public void createTable(String table, List<byte[]> cfs) throws IOException {
         TableDescriptorBuilder tdb = TableDescriptorBuilder.newBuilder(
-                                     TableName.valueOf(this.namespace, table));
+                TableName.valueOf(this.namespace, table));
         for (byte[] cf : cfs) {
             tdb.setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(cf)
                                                              .build());
@@ -237,7 +237,7 @@ public class HbaseSessions extends BackendSessionPool {
             builder.setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(cf).build());
         }
         byte[][] splits = new byte[numOfPartitions - 1]
-                                  [org.apache.hadoop.hbase.util.Bytes.SIZEOF_SHORT];
+                [org.apache.hadoop.hbase.util.Bytes.SIZEOF_SHORT];
         for (short split = 1; split < numOfPartitions; split++) {
             splits[split - 1] = org.apache.hadoop.hbase.util.Bytes.toBytes(split);
         }
@@ -421,7 +421,7 @@ public class HbaseSessions extends BackendSessionPool {
         default R scan(String table, byte[] startRow, boolean inclusiveStart,
                        byte[] prefix) {
             final Scan scan = new Scan();
-            if(startRow == prefix) {
+            if (startRow == prefix) {
                 scan.setRowPrefixFilter(prefix);
             } else {
                 scan.withStartRow(startRow, inclusiveStart)
@@ -465,7 +465,7 @@ public class HbaseSessions extends BackendSessionPool {
      * Session implement for HBase
      */
     public class Session extends AbstractBackendSession
-                         implements HbaseSession<RowIterator> {
+            implements HbaseSession<RowIterator> {
 
         private final Map<String, List<Row>> batch;
 
@@ -491,7 +491,7 @@ public class HbaseSessions extends BackendSessionPool {
         }
 
         private void checkBatchResults(Object[] results, List<Row> rows)
-                                       throws Throwable {
+                throws Throwable {
             assert rows.size() == results.length;
             for (int i = 0; i < results.length; i++) {
                 Object result = results[i];
@@ -560,7 +560,7 @@ public class HbaseSessions extends BackendSessionPool {
                 } catch (Throwable e) {
                     // TODO: Mark and delete committed records
                     throw new BackendException("Failed to commit, " +
-                              "there may be inconsistent states for HBase", e);
+                                               "there may be inconsistent states for HBase", e);
                 }
             }
 
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseStore.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseStore.java
index e98d2cd24..70091bec8 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseStore.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseStore.java
@@ -30,8 +30,6 @@ import java.util.stream.Collectors;
 import org.apache.hadoop.hbase.NamespaceExistException;
 import org.apache.hadoop.hbase.TableExistsException;
 import org.apache.hadoop.hbase.TableNotFoundException;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Query;
@@ -46,6 +44,7 @@ import org.apache.hugegraph.exception.ConnectionException;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Session> {
 
@@ -111,7 +110,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
 
     protected List<String> tableNames() {
         return this.tables.values().stream().map(t -> t.table())
-                                            .collect(Collectors.toList());
+                          .collect(Collectors.toList());
     }
 
     public String namespace() {
@@ -190,7 +189,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
         this.checkOpened();
         HbaseSessions.Session session = this.sessions.session();
 
-        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext();) {
+        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext(); ) {
             this.mutate(session, it.next());
         }
     }
@@ -220,7 +219,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported mutate action: %s", item.action()));
+                        "Unsupported mutate action: %s", item.action()));
         }
     }
 
@@ -253,8 +252,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
             // Ignore due to both schema & graph store would create namespace
         } catch (IOException e) {
             throw new BackendException(
-                      "Failed to create namespace '%s' for '%s' store",
-                      e, this.namespace, this.store);
+                    "Failed to create namespace '%s' for '%s' store",
+                    e, this.namespace, this.store);
         }
 
         // Create tables
@@ -262,10 +261,10 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
             try {
                 if (table.equals("g_oe") || table.equals("g_ie")) {
                     this.sessions.createPreSplitTable(table, HbaseTable.cfs(),
-                        this.edgeLogicPartitions);
+                                                      this.edgeLogicPartitions);
                 } else if (table.equals("g_v")) {
-                    this.sessions.createPreSplitTable(table, HbaseTable.cfs(), 
-                        this.vertexLogicPartitions);
+                    this.sessions.createPreSplitTable(table, HbaseTable.cfs(),
+                                                      this.vertexLogicPartitions);
                 } else {
                     this.sessions.createTable(table, HbaseTable.cfs());
                 }
@@ -274,8 +273,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
                 continue;
             } catch (IOException e) {
                 throw new BackendException(
-                          "Failed to create table '%s' for '%s' store",
-                          e, table, this.store);
+                        "Failed to create table '%s' for '%s' store",
+                        e, table, this.store);
             }
         }
 
@@ -293,8 +292,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
             }
         } catch (IOException e) {
             throw new BackendException(
-                      "Exception when checking for the existence of '%s'",
-                      e, this.namespace);
+                    "Exception when checking for the existence of '%s'",
+                    e, this.namespace);
         }
 
         if (!clearSpace) {
@@ -307,8 +306,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
                              "when trying to drop", table, this.store);
                 } catch (IOException e) {
                     throw new BackendException(
-                              "Failed to drop table '%s' of '%s' store",
-                              e, table, this.store);
+                            "Failed to drop table '%s' of '%s' store",
+                            e, table, this.store);
                 }
             }
         } else {
@@ -322,8 +321,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
                               this.namespace, e);
                 } else {
                     throw new BackendException(
-                              "Failed to drop namespace '%s' of '%s' store",
-                              e, this.namespace, this.store);
+                            "Failed to drop namespace '%s' of '%s' store",
+                            e, this.namespace, this.store);
                 }
             }
         }
@@ -365,8 +364,8 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
                 return future.get(remainingTime, TimeUnit.SECONDS);
             } catch (Exception e) {
                 throw new BackendException(
-                          "Error when truncating table '%s' of '%s' store: %s",
-                          table, this.store, e.toString());
+                        "Error when truncating table '%s' of '%s' store: %s",
+                        table, this.store, e.toString());
             }
         };
 
@@ -385,7 +384,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
         } catch (Exception e) {
             this.enableTables();
             throw new BackendException(
-                      "Failed to disable table for '%s' store", e, this.store);
+                    "Failed to disable table for '%s' store", e, this.store);
         }
 
         try {
@@ -399,7 +398,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
         } catch (Exception e) {
             this.enableTables();
             throw new BackendException(
-                      "Failed to truncate table for '%s' store", e, this.store);
+                    "Failed to truncate table for '%s' store", e, this.store);
         }
 
         LOG.debug("Store truncated: {}", this.store);
@@ -450,7 +449,7 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
 
         public HbaseSchemaStore(HugeConfig config, BackendStoreProvider provider,
                                 String namespace, String store) {
-            super(provider, namespace, store, 
+            super(provider, namespace, store,
                   config.get(HbaseOptions.HBASE_ENABLE_PARTITION).booleanValue());
 
             this.counters = new HbaseTables.Counters();
@@ -495,10 +494,12 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
     }
 
     public static class HbaseGraphStore extends HbaseStore {
+
         private boolean enablePartition;
+
         public HbaseGraphStore(HugeConfig config, BackendStoreProvider provider,
                                String namespace, String store) {
-            super(provider, namespace, store, 
+            super(provider, namespace, store,
                   config.get(HbaseOptions.HBASE_ENABLE_PARTITION).booleanValue());
             this.enablePartition = config.get(HbaseOptions.HBASE_ENABLE_PARTITION).booleanValue();
             registerTableManager(HugeType.VERTEX,
@@ -539,19 +540,19 @@ public abstract class HbaseStore extends AbstractBackendStore<HbaseSessions.Sess
         @Override
         public Id nextId(HugeType type) {
             throw new UnsupportedOperationException(
-                      "HbaseGraphStore.nextId()");
+                    "HbaseGraphStore.nextId()");
         }
 
         @Override
         public void increaseCounter(HugeType type, long num) {
             throw new UnsupportedOperationException(
-                      "HbaseGraphStore.increaseCounter()");
+                    "HbaseGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "HbaseGraphStore.getCounter()");
+                    "HbaseGraphStore.getCounter()");
         }
     }
 
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTable.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTable.java
index cb915452d..53a8d14f6 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTable.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTable.java
@@ -37,8 +37,6 @@ import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.Result;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.page.PageState;
@@ -63,6 +61,8 @@ import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.StringEncoding;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableList;
 
 public class HbaseTable extends BackendTable<HbaseSessions.Session, BackendEntry> {
@@ -287,7 +287,7 @@ public class HbaseTable extends BackendTable<HbaseSessions.Session, BackendEntry
 
     protected void parseRowColumns(Result row, BackendEntry entry, Query query,
                                    boolean enablePartition)
-                                   throws IOException {
+            throws IOException {
         CellScanner cellScanner = row.cellScanner();
         while (cellScanner.advance()) {
             Cell cell = cellScanner.current();
@@ -336,7 +336,7 @@ public class HbaseTable extends BackendTable<HbaseSessions.Session, BackendEntry
                 TableName tableName = TableName.valueOf(namespace, table);
                 for (ServerName serverName : admin.getRegionServers()) {
                     List<RegionMetrics> metrics = admin.getRegionMetrics(
-                                                  serverName, tableName);
+                            serverName, tableName);
                     for (RegionMetrics metric : metrics) {
                         double size = metric.getStoreFileSize()
                                             .get(Size.Unit.BYTE);
@@ -346,8 +346,8 @@ public class HbaseTable extends BackendTable<HbaseSessions.Session, BackendEntry
                 }
             } catch (Throwable e) {
                 throw new BackendException(String.format(
-                          "Failed to get region sizes of %s(%s)",
-                          table, namespace), e);
+                        "Failed to get region sizes of %s(%s)",
+                        table, namespace), e);
             }
             return regionSizes;
         }
@@ -366,8 +366,8 @@ public class HbaseTable extends BackendTable<HbaseSessions.Session, BackendEntry
                 }
             } catch (Throwable e) {
                 throw new BackendException(String.format(
-                          "Failed to get region ranges of %s(%s)",
-                          table, namespace), e);
+                        "Failed to get region ranges of %s(%s)",
+                        table, namespace), e);
             }
             return regionRanges;
         }
diff --git a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTables.java b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTables.java
index b6df03114..c3cda4031 100644
--- a/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTables.java
+++ b/hugegraph-server/hugegraph-hbase/src/main/java/org/apache/hugegraph/backend/store/hbase/HbaseTables.java
@@ -20,16 +20,15 @@ package org.apache.hugegraph.backend.store.hbase;
 import java.io.IOException;
 import java.util.Arrays;
 
-import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.util.Bytes;
-
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.serializer.BinaryBackendEntry;
 import org.apache.hugegraph.backend.serializer.BinaryEntryIterator;
+import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
 import org.apache.hugegraph.backend.store.BackendEntryIterator;
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlEntryIterator.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlEntryIterator.java
index 00732a965..f4857165c 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlEntryIterator.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlEntryIterator.java
@@ -45,7 +45,7 @@ public class MysqlEntryIterator extends BackendEntryIterator {
     private boolean exceedLimit;
 
     public MysqlEntryIterator(ResultSetWrapper rs, Query query,
-           BiFunction<BackendEntry, BackendEntry, BackendEntry> merger) {
+                              BiFunction<BackendEntry, BackendEntry, BackendEntry> merger) {
         super(query);
         this.results = rs;
         this.merger = merger;
@@ -100,7 +100,7 @@ public class MysqlEntryIterator extends BackendEntryIterator {
         byte[] position;
         // There is no latest or no next page
         if (this.lastest == null || !this.exceedLimit &&
-            this.fetched() <= this.query.limit() && this.next == null) {
+                                    this.fetched() <= this.query.limit() && this.next == null) {
             position = PageState.EMPTY_BYTES;
         } else {
             MysqlBackendEntry entry = (MysqlBackendEntry) this.lastest;
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlMetrics.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlMetrics.java
index a4769d2c1..4d4019d9a 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlMetrics.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlMetrics.java
@@ -20,6 +20,7 @@ package org.apache.hugegraph.backend.store.mysql;
 import java.util.Map;
 
 import org.apache.hugegraph.backend.store.BackendMetrics;
+
 import com.google.common.collect.ImmutableMap;
 
 public class MysqlMetrics implements BackendMetrics {
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlOptions.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlOptions.java
index d2449a54c..dd46fdb5d 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlOptions.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlOptions.java
@@ -108,9 +108,9 @@ public class MysqlOptions extends OptionHolder {
 
     public static final ConfigOption<String> JDBC_STORAGE_ENGINE =
             new ConfigOption<>(
-                   "jdbc.storage_engine",
-                   "The storage engine of backend store database, " +
-                   "like InnoDB/MyISAM/RocksDB for MySQL.",
+                    "jdbc.storage_engine",
+                    "The storage engine of backend store database, " +
+                    "like InnoDB/MyISAM/RocksDB for MySQL.",
                     disallowEmpty(),
                     "InnoDB"
             );
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSerializer.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSerializer.java
index 3a47e7ada..1557902bd 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSerializer.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSerializer.java
@@ -22,15 +22,14 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.hugegraph.config.HugeConfig;
 import org.apache.commons.lang.NotImplementedException;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.serializer.TableBackendEntry;
 import org.apache.hugegraph.backend.serializer.TableSerializer;
 import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.structure.HugeProperty;
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSessions.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSessions.java
index 8ea17e834..9124c3a4b 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSessions.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlSessions.java
@@ -30,15 +30,14 @@ import java.util.Map;
 import java.util.stream.IntStream;
 
 import org.apache.http.client.utils.URIBuilder;
-import org.apache.logging.log4j.util.Strings;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.BackendSession.AbstractBackendSession;
 import org.apache.hugegraph.backend.store.BackendSessionPool;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.logging.log4j.util.Strings;
+import org.slf4j.Logger;
 
 public class MysqlSessions extends BackendSessionPool {
 
@@ -74,6 +73,7 @@ public class MysqlSessions extends BackendSessionPool {
 
     /**
      * Try connect with specified database, will not reconnect if failed
+     *
      * @throws SQLException if a database access error occurs
      */
     @Override
@@ -220,7 +220,7 @@ public class MysqlSessions extends BackendSessionPool {
         String url = this.buildUrlPrefix(withDB);
 
         boolean forcedAutoReconnect = this.config.get(
-                                      MysqlOptions.JDBC_FORCED_AUTO_RECONNECT);
+                MysqlOptions.JDBC_FORCED_AUTO_RECONNECT);
         int maxTimes = this.config.get(MysqlOptions.JDBC_RECONNECT_MAX_TIMES);
         int interval = this.config.get(MysqlOptions.JDBC_RECONNECT_INTERVAL);
         String sslMode = this.config.get(MysqlOptions.JDBC_SSL_MODE);
@@ -253,7 +253,7 @@ public class MysqlSessions extends BackendSessionPool {
 
         builder.setParameter("useSSL", sslMode);
 
-        return JDBC_PREFIX + builder.toString();
+        return JDBC_PREFIX + builder;
     }
 
     protected String buildUrlPrefix(boolean withDB) {
@@ -270,7 +270,7 @@ public class MysqlSessions extends BackendSessionPool {
     }
 
     protected URIBuilder newConnectionURIBuilder(String url)
-                                                 throws URISyntaxException {
+            throws URISyntaxException {
         return new URIBuilder(url);
     }
 
@@ -283,8 +283,10 @@ public class MysqlSessions extends BackendSessionPool {
             // Register JDBC driver
             Class.forName(driverName);
         } catch (ClassNotFoundException e) {
-            throw new BackendException("Failed to register JDBC driver. Class '%s' not found. Please check if the MySQL driver package is available.",
-                                       driverName);
+            throw new BackendException(
+                    "Failed to register JDBC driver. Class '%s' not found. Please check if the " +
+                    "MySQL driver package is available.",
+                    driverName);
         }
         return DriverManager.getConnection(url, username, password);
     }
@@ -532,7 +534,7 @@ public class MysqlSessions extends BackendSessionPool {
         }
 
         public PreparedStatement prepareStatement(String sqlTemplate)
-                                                  throws SQLException {
+                throws SQLException {
             PreparedStatement statement = this.statements.get(sqlTemplate);
             if (statement == null) {
                 statement = this.conn.prepareStatement(sqlTemplate);
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlStore.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlStore.java
index 7952b5400..c5d983fef 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlStore.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlStore.java
@@ -25,8 +25,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Query;
@@ -42,6 +40,7 @@ import org.apache.hugegraph.exception.ConnectionException;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class MysqlStore extends AbstractBackendStore<Session> {
 
@@ -236,7 +235,7 @@ public abstract class MysqlStore extends AbstractBackendStore<Session> {
         this.checkOpened();
         Session session = this.sessions.session();
 
-        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext();) {
+        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext(); ) {
             this.mutate(session, it.next());
         }
     }
@@ -266,7 +265,7 @@ public abstract class MysqlStore extends AbstractBackendStore<Session> {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported mutate action: %s", item.action()));
+                        "Unsupported mutate action: %s", item.action()));
         }
     }
 
@@ -370,7 +369,7 @@ public abstract class MysqlStore extends AbstractBackendStore<Session> {
     protected static MysqlBackendEntry castBackendEntry(BackendEntry entry) {
         if (!(entry instanceof MysqlBackendEntry)) {
             throw new BackendException(
-                      "MySQL store only supports MysqlBackendEntry");
+                    "MySQL store only supports MysqlBackendEntry");
         }
         return (MysqlBackendEntry) entry;
     }
@@ -467,13 +466,13 @@ public abstract class MysqlStore extends AbstractBackendStore<Session> {
         @Override
         public void increaseCounter(HugeType type, long num) {
             throw new UnsupportedOperationException(
-                      "MysqlGraphStore.increaseCounter()");
+                    "MysqlGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "MysqlGraphStore.getCounter()");
+                    "MysqlGraphStore.getCounter()");
         }
     }
 
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTable.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTable.java
index 2bc035e0b..c00003361 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTable.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTable.java
@@ -27,10 +27,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.BiFunction;
 
-import org.apache.logging.log4j.util.Strings;
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.page.PageState;
@@ -50,10 +46,14 @@ import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.logging.log4j.util.Strings;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableList;
 
 public abstract class MysqlTable
-                extends BackendTable<MysqlSessions.Session, MysqlBackendEntry.Row> {
+        extends BackendTable<MysqlSessions.Session, MysqlBackendEntry.Row> {
 
     private static final Logger LOG = Log.logger(MysqlTable.class);
 
@@ -111,7 +111,7 @@ public abstract class MysqlTable
         sql.append(this.table()).append(" (");
         // Add columns
         for (Map.Entry<HugeKeys, String> entry :
-             tableDefine.columns().entrySet()) {
+                tableDefine.columns().entrySet()) {
             sql.append(formatKey(entry.getKey()));
             sql.append(" ");
             sql.append(entry.getValue());
@@ -458,7 +458,7 @@ public abstract class MysqlTable
 
     protected <R> Iterator<R> query(MysqlSessions.Session session, Query query,
                                     BiFunction<Query, ResultSetWrapper,
-                                               Iterator<R>> parser) {
+                                            Iterator<R>> parser) {
         ExtendableIterator<R> rs = new ExtendableIterator<>();
 
         if (query.limit() == 0L && !query.noLimit()) {
@@ -494,7 +494,7 @@ public abstract class MysqlTable
         // Set aggregate
         Aggregate aggregate = query.aggregate();
         if (aggregate != null) {
-            select.append(aggregate.toString());
+            select.append(aggregate);
         } else {
             select.append("*");
         }
@@ -610,8 +610,8 @@ public abstract class MysqlTable
             List<Object> idParts = this.idColumnValue(id);
             if (nameParts.size() != idParts.size()) {
                 throw new NotFoundException(
-                          "Unsupported ID format: '%s' (should contain %s)",
-                          id, nameParts);
+                        "Unsupported ID format: '%s' (should contain %s)",
+                        id, nameParts);
             }
             ids.add(idParts);
         }
@@ -714,7 +714,7 @@ public abstract class MysqlTable
         // Set order-by
         select.append(" ORDER BY ");
         for (Map.Entry<HugeKeys, Query.Order> order :
-             query.orders().entrySet()) {
+                query.orders().entrySet()) {
             String key = formatKey(order.getKey());
             Query.Order value = order.getValue();
             select.append(key).append(" ");
@@ -736,7 +736,7 @@ public abstract class MysqlTable
         if (!page.isEmpty()) {
             byte[] position = PageState.fromString(page).position();
             Map<HugeKeys, Object> columns = MysqlEntryIterator.PagePosition.fromBytes(position)
-                                                        .columns();
+                                                                           .columns();
 
             List<HugeKeys> idColumnNames = this.idColumnName();
             List<Object> values = new ArrayList<>(idColumnNames.size());
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTables.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTables.java
index 2de6e95d5..dccbfedd4 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTables.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTables.java
@@ -38,6 +38,7 @@ import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.collect.ImmutableMap;
 
 public class MysqlTables {
@@ -124,7 +125,7 @@ public class MysqlTables {
                 return rs.getString(formatKey(HugeKeys.VALUE));
             } catch (SQLException e) {
                 throw new BackendException(
-                          "Failed to get stored version with '%s'", e, select);
+                        "Failed to get stored version with '%s'", e, select);
             }
         }
     }
@@ -161,17 +162,17 @@ public class MysqlTables {
                 }
             } catch (SQLException e) {
                 throw new BackendException(
-                          "Failed to get id from counters with type '%s'",
-                          e, type);
+                        "Failed to get id from counters with type '%s'",
+                        e, type);
             }
         }
 
         public void increaseCounter(MysqlSessions.Session session,
                                     HugeType type, long increment) {
             String update = String.format(
-                            "INSERT INTO %s VALUES ('%s', %s) " +
-                            "ON DUPLICATE KEY UPDATE ID = ID + %s;",
-                            this.table(), type.name(), increment, increment);
+                    "INSERT INTO %s VALUES ('%s', %s) " +
+                    "ON DUPLICATE KEY UPDATE ID = ID + %s;",
+                    this.table(), type.name(), increment, increment);
             try {
                 session.execute(update);
             } catch (SQLException e) {
@@ -325,8 +326,8 @@ public class MysqlTables {
 
             this.direction = direction;
             this.delByLabelTemplate = String.format(
-                                      "DELETE FROM %s WHERE %s = ?;",
-                                      this.table(), formatKey(HugeKeys.LABEL));
+                    "DELETE FROM %s WHERE %s = ?;",
+                    this.table(), formatKey(HugeKeys.LABEL));
 
             this.define = new TableDefine(typesMapping);
             this.define.column(HugeKeys.OWNER_VERTEX, SMALL_TEXT);
@@ -350,7 +351,7 @@ public class MysqlTables {
                 String[] idParts = EdgeId.split(id);
                 if (idParts.length == 1) {
                     // Delete edge by label
-                    return Arrays.asList((Object[]) idParts);
+                    return Arrays.asList(idParts);
                 }
                 id = IdUtil.readString(id.asString());
                 edgeId = EdgeId.parse(id.asString());
@@ -412,7 +413,7 @@ public class MysqlTables {
             long maxSize = BackendEntryIterator.INLINE_BATCH_SIZE;
             if (current != null && current.subRows().size() < maxSize) {
                 Id nextVertexId = IdGenerator.of(
-                                  next.<String>column(HugeKeys.OWNER_VERTEX));
+                        next.<String>column(HugeKeys.OWNER_VERTEX));
                 if (current.id().equals(nextVertexId)) {
                     current.subRow(next.row());
                     return current;
diff --git a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/WhereBuilder.java b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/WhereBuilder.java
index 4a559a67b..5eb0fb44a 100644
--- a/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/WhereBuilder.java
+++ b/hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/WhereBuilder.java
@@ -81,6 +81,7 @@ public class WhereBuilder {
 
     /**
      * Concat as: cond1 and cond2...
+     *
      * @return WhereBuilder
      */
     public WhereBuilder and() {
@@ -90,7 +91,8 @@ public class WhereBuilder {
 
     /**
      * Concat as: key1 op ? and key2 op ?...
-     * @param keys the keys to be concatted with value
+     *
+     * @param keys     the keys to be concatted with value
      * @param operator the operator to link every key and value pair
      * @return WhereBuilder
      */
@@ -108,8 +110,9 @@ public class WhereBuilder {
 
     /**
      * Concat as: key1 = value1 and key2 = value2...
-     * @param keys the keys to be concatted with values according to the
-     *             same index
+     *
+     * @param keys   the keys to be concatted with values according to the
+     *               same index
      * @param values the values to be concatted with every keys according to
      *               the same index
      * @return WhereBuilder
@@ -120,11 +123,12 @@ public class WhereBuilder {
 
     /**
      * Concat as: key1 op value1 and key2 op value2...
-     * @param keys the keys to be concatted with values according to the
-     *             same index
+     *
+     * @param keys     the keys to be concatted with values according to the
+     *                 same index
      * @param operator the operator to link every key and value pair
-     * @param values the values to be concatted with every keys according to
-     *               the same index
+     * @param values   the values to be concatted with every keys according to
+     *                 the same index
      * @return WhereBuilder
      */
     public WhereBuilder and(List<String> keys,
@@ -148,12 +152,13 @@ public class WhereBuilder {
 
     /**
      * Concat as: key1 op1 value1 and key2 op2 value2...
-     * @param keys the keys to be concatted with values according to the
-     *             same index
+     *
+     * @param keys      the keys to be concatted with values according to the
+     *                  same index
      * @param operators the operators to link every key and value pair
      *                  according to the same index
-     * @param values the values to be concatted with every keys according to
-     *               the same index
+     * @param values    the values to be concatted with every keys according to
+     *                  the same index
      * @return WhereBuilder
      */
     public WhereBuilder and(List<String> keys,
@@ -181,6 +186,7 @@ public class WhereBuilder {
 
     /**
      * Concat as: clause1 and clause2...
+     *
      * @param clauses the clauses to be concatted with 'AND' operator
      * @return WhereBuilder
      */
@@ -201,7 +207,8 @@ public class WhereBuilder {
 
     /**
      * Concat as: key in (value1, value2...)
-     * @param key the key to be concatted with 'IN' operator
+     *
+     * @param key    the key to be concatted with 'IN' operator
      * @param values the values to be concated with ',' and wrapped by '()'
      * @return WhereBuilder
      */
@@ -219,7 +226,8 @@ public class WhereBuilder {
 
     /**
      * Concat as: (key1, key2...keyn) {@code >=} (val1, val2...valn)
-     * @param keys the keys to be concatted with {@code >=} operator
+     *
+     * @param keys   the keys to be concatted with {@code >=} operator
      * @param values the values to be concatted with {@code >=} operator
      * @return WhereBuilder
      */
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloFile.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloFile.java
index e75a4074f..d9aed31c0 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloFile.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloFile.java
@@ -27,10 +27,10 @@ import java.util.List;
 import java.util.Set;
 
 import org.apache.commons.io.FileUtils;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.base.Charsets;
 import com.google.common.collect.ImmutableList;
 
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloSessions.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloSessions.java
index e13fbb919..735645eab 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloSessions.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloSessions.java
@@ -34,14 +34,14 @@ import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
-import org.apache.hugegraph.backend.store.mysql.ResultSetWrapper;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
+import org.apache.hugegraph.backend.store.mysql.ResultSetWrapper;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.date.SafeDateFormat;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.Multimap;
 
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStore.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStore.java
index 20e95639d..344800868 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStore.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStore.java
@@ -20,13 +20,12 @@ package org.apache.hugegraph.backend.store.palo;
 import java.util.List;
 import java.util.stream.Collectors;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.store.BackendStoreProvider;
 import org.apache.hugegraph.backend.store.BackendTable;
 import org.apache.hugegraph.backend.store.mysql.MysqlStore;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class PaloStore extends MysqlStore {
 
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStoreProvider.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStoreProvider.java
index 76451100b..bde8d264e 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStoreProvider.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloStoreProvider.java
@@ -163,13 +163,13 @@ public class PaloStoreProvider extends MysqlStoreProvider {
         @Override
         public void increaseCounter(HugeType type, long num) {
             throw new UnsupportedOperationException(
-                      "PaloGraphStore.increaseCounter()");
+                    "PaloGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "PaloGraphStore.getCounter()");
+                    "PaloGraphStore.getCounter()");
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTable.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTable.java
index 076865a3c..f40eef214 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTable.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTable.java
@@ -24,8 +24,6 @@ import java.util.Map;
 import java.util.Set;
 
 import org.apache.commons.lang3.StringUtils;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.TableDefine;
 import org.apache.hugegraph.backend.store.mysql.MysqlBackendEntry;
@@ -33,6 +31,7 @@ import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
 import org.apache.hugegraph.backend.store.mysql.MysqlTable;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class PaloTable extends MysqlTable {
 
@@ -51,7 +50,7 @@ public abstract class PaloTable extends MysqlTable {
         // Add columns
         int i = 0;
         for (Map.Entry<HugeKeys, String> entry :
-             tableDefine.columns().entrySet()) {
+                tableDefine.columns().entrySet()) {
             sql.append(formatKey(entry.getKey()));
             sql.append(" ");
             sql.append(entry.getValue());
diff --git a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTables.java b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTables.java
index e82436c10..51c3dcea9 100644
--- a/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTables.java
+++ b/hugegraph-server/hugegraph-palo/src/main/java/org/apache/hugegraph/backend/store/palo/PaloTables.java
@@ -188,9 +188,9 @@ public class PaloTables {
 
             this.direction = direction;
             this.delByLabelTemplate = String.format(
-                                      "DELETE FROM %s PARTITION %s WHERE %s = ?;",
-                                      this.table(), this.table(),
-                                      formatKey(HugeKeys.LABEL));
+                    "DELETE FROM %s PARTITION %s WHERE %s = ?;",
+                    this.table(), this.table(),
+                    formatKey(HugeKeys.LABEL));
 
             this.define = new TableDefine();
             this.define.column(HugeKeys.OWNER_VERTEX, VARCHAR, NOT_NULL);
@@ -214,7 +214,7 @@ public class PaloTables {
                 String[] idParts = EdgeId.split(id);
                 if (idParts.length == 1) {
                     // Delete edge by label
-                    return Arrays.asList((Object[]) idParts);
+                    return Arrays.asList(idParts);
                 }
                 id = IdUtil.readString(id.asString());
                 edgeId = EdgeId.parse(id.asString());
@@ -280,7 +280,7 @@ public class PaloTables {
             long maxSize = BackendEntryIterator.INLINE_BATCH_SIZE;
             if (current != null && current.subRows().size() < maxSize) {
                 Id nextVertexId = IdGenerator.of(
-                                  next.<String>column(HugeKeys.OWNER_VERTEX));
+                        next.<String>column(HugeKeys.OWNER_VERTEX));
                 if (current.id().equals(nextVertexId)) {
                     current.subRow(next.row());
                     return current;
diff --git a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSerializer.java b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSerializer.java
index bdf3959a4..c0bd23a7e 100644
--- a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSerializer.java
+++ b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSerializer.java
@@ -17,15 +17,14 @@
 
 package org.apache.hugegraph.backend.store.postgresql;
 
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.logging.log4j.util.Strings;
-
 import org.apache.hugegraph.backend.id.IdUtil;
 import org.apache.hugegraph.backend.serializer.TableBackendEntry;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.mysql.MysqlSerializer;
+import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.type.define.HugeKeys;
+import org.apache.logging.log4j.util.Strings;
 
 public class PostgresqlSerializer extends MysqlSerializer {
 
diff --git a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSessions.java b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSessions.java
index 0d1beff61..cccbb6945 100644
--- a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSessions.java
+++ b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlSessions.java
@@ -23,15 +23,14 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 
 import org.apache.http.client.utils.URIBuilder;
-import org.postgresql.core.Utils;
-import org.postgresql.util.PSQLException;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
 import org.apache.hugegraph.backend.store.mysql.MysqlUtil;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.Log;
+import org.postgresql.core.Utils;
+import org.postgresql.util.PSQLException;
+import org.slf4j.Logger;
 
 public class PostgresqlSessions extends MysqlSessions {
 
@@ -40,7 +39,8 @@ public class PostgresqlSessions extends MysqlSessions {
     private static final String COCKROACH_DB_CREATE =
             "CREATE DATABASE %s ENCODING='UTF-8'";
     private static final String POSTGRESQL_DB_CREATE = COCKROACH_DB_CREATE +
-            " TEMPLATE=template0 LC_COLLATE='C' LC_CTYPE='C';";
+                                                       " TEMPLATE=template0 LC_COLLATE='C' " +
+                                                       "LC_CTYPE='C';";
 
     public PostgresqlSessions(HugeConfig config, String database, String store) {
         super(config, database, store);
@@ -49,8 +49,8 @@ public class PostgresqlSessions extends MysqlSessions {
     @Override
     public boolean existsDatabase() {
         String statement = String.format(
-                           "SELECT datname FROM pg_catalog.pg_database " +
-                           "WHERE datname = '%s';", this.escapedDatabase());
+                "SELECT datname FROM pg_catalog.pg_database " +
+                "WHERE datname = '%s';", this.escapedDatabase());
         try (Connection conn = this.openWithoutDB(0)) {
             ResultSet result = conn.createStatement().executeQuery(statement);
             return result.next();
@@ -93,25 +93,25 @@ public class PostgresqlSessions extends MysqlSessions {
     @Override
     protected String buildDropDatabase(String database) {
         return String.format(
-               "REVOKE CONNECT ON DATABASE %s FROM public;" +
-               "SELECT pg_terminate_backend(pg_stat_activity.pid) " +
-               "  FROM pg_stat_activity " +
-               "  WHERE pg_stat_activity.datname = %s;" +
-               "DROP DATABASE IF EXISTS %s;",
-               database, escapeAndWrapString(database), database);
+                "REVOKE CONNECT ON DATABASE %s FROM public;" +
+                "SELECT pg_terminate_backend(pg_stat_activity.pid) " +
+                "  FROM pg_stat_activity " +
+                "  WHERE pg_stat_activity.datname = %s;" +
+                "DROP DATABASE IF EXISTS %s;",
+                database, escapeAndWrapString(database), database);
     }
 
     @Override
     protected String buildExistsTable(String table) {
         return String.format(
-               "SELECT * FROM information_schema.tables " +
-               "WHERE table_schema = 'public' AND table_name = '%s' LIMIT 1;",
-               MysqlUtil.escapeString(table));
+                "SELECT * FROM information_schema.tables " +
+                "WHERE table_schema = 'public' AND table_name = '%s' LIMIT 1;",
+                MysqlUtil.escapeString(table));
     }
 
     @Override
     protected URIBuilder newConnectionURIBuilder(String url)
-                                                 throws URISyntaxException {
+            throws URISyntaxException {
         // Suppress error log when database does not exist
         return new URIBuilder(url).addParameter("loggerLevel", "OFF");
     }
diff --git a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlStoreProvider.java b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlStoreProvider.java
index a6124d817..65ed8e0fa 100644
--- a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlStoreProvider.java
+++ b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlStoreProvider.java
@@ -21,8 +21,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.backend.store.BackendStoreProvider;
@@ -33,6 +31,7 @@ import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class PostgresqlStoreProvider extends MysqlStoreProvider {
 
@@ -167,19 +166,19 @@ public class PostgresqlStoreProvider extends MysqlStoreProvider {
         @Override
         public Id nextId(HugeType type) {
             throw new UnsupportedOperationException(
-                      "PostgresqlGraphStore.nextId()");
+                    "PostgresqlGraphStore.nextId()");
         }
 
         @Override
         public void increaseCounter(HugeType type, long increment) {
             throw new UnsupportedOperationException(
-                      "PostgresqlGraphStore.increaseCounter()");
+                    "PostgresqlGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "PostgresqlGraphStore.getCounter()");
+                    "PostgresqlGraphStore.getCounter()");
         }
     }
 
diff --git a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTable.java b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTable.java
index 40ffb22c6..555615fe7 100644
--- a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTable.java
+++ b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTable.java
@@ -20,14 +20,13 @@ package org.apache.hugegraph.backend.store.postgresql;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.logging.log4j.util.Strings;
-
 import org.apache.hugegraph.backend.serializer.TableBackendEntry.Row;
 import org.apache.hugegraph.backend.store.mysql.MysqlBackendEntry;
 import org.apache.hugegraph.backend.store.mysql.MysqlSessions.Session;
 import org.apache.hugegraph.backend.store.mysql.MysqlTable;
 import org.apache.hugegraph.backend.store.mysql.WhereBuilder;
 import org.apache.hugegraph.type.define.HugeKeys;
+import org.apache.logging.log4j.util.Strings;
 
 public abstract class PostgresqlTable extends MysqlTable {
 
@@ -162,7 +161,8 @@ public abstract class PostgresqlTable extends MysqlTable {
         @Override
         protected String escapeAndWrapString(String value) {
             if (value.equals("\u0000")) {
-                return "\'\'";
+                /* PR-2439 return string of '' */
+                return "''";
             }
             return PostgresqlSessions.escapeAndWrapString(value);
         }
diff --git a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTables.java b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTables.java
index 0cf6e604e..d57ad3c2d 100644
--- a/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTables.java
+++ b/hugegraph-server/hugegraph-postgresql/src/main/java/org/apache/hugegraph/backend/store/postgresql/PostgresqlTables.java
@@ -48,15 +48,15 @@ public class PostgresqlTables {
 
     private static final Map<String, String> TYPES_MAPPING =
             ImmutableMap.<String, String>builder()
-                    .put(BOOLEAN, "BOOL")
-                    .put(TINYINT, "INT")
-                    .put(INT, "INT")
-                    .put(NUMERIC, "DECIMAL")
-                    .put(SMALL_TEXT, "VARCHAR(255)")
-                    .put(MID_TEXT, "VARCHAR(1024)")
-                    .put(LARGE_TEXT, "VARCHAR(65533)")
-                    .put(HUGE_TEXT, "TEXT")
-                    .build();
+                        .put(BOOLEAN, "BOOL")
+                        .put(TINYINT, "INT")
+                        .put(INT, "INT")
+                        .put(NUMERIC, "DECIMAL")
+                        .put(SMALL_TEXT, "VARCHAR(255)")
+                        .put(MID_TEXT, "VARCHAR(1024)")
+                        .put(LARGE_TEXT, "VARCHAR(65533)")
+                        .put(HUGE_TEXT, "TEXT")
+                        .build();
 
     public static class PostgresqlTableTemplate extends PostgresqlTable {
 
@@ -112,17 +112,17 @@ public class PostgresqlTables {
         public void increaseCounter(Session session, HugeType type,
                                     long increment) {
             String update = String.format(
-                            "INSERT INTO %s (%s, %s) VALUES ('%s', %s) " +
-                            "ON CONFLICT (%s) DO UPDATE SET ID = %s.ID + %s;",
-                            this.table(), formatKey(HugeKeys.SCHEMA_TYPE),
-                            formatKey(HugeKeys.ID), type.name(), increment,
-                            formatKey(HugeKeys.SCHEMA_TYPE),
-                            this.table(), increment);
+                    "INSERT INTO %s (%s, %s) VALUES ('%s', %s) " +
+                    "ON CONFLICT (%s) DO UPDATE SET ID = %s.ID + %s;",
+                    this.table(), formatKey(HugeKeys.SCHEMA_TYPE),
+                    formatKey(HugeKeys.ID), type.name(), increment,
+                    formatKey(HugeKeys.SCHEMA_TYPE),
+                    this.table(), increment);
             try {
                 session.execute(update);
             } catch (SQLException e) {
                 throw new BackendException(
-                          "Failed to update counters with type '%s'", e, type);
+                        "Failed to update counters with type '%s'", e, type);
             }
         }
     }
@@ -274,7 +274,7 @@ public class PostgresqlTables {
 
         protected final String entryId(MysqlBackendEntry entry) {
             return ((MysqlTables.RangeDoubleIndex) this.template)
-                   .entryId(entry);
+                    .entryId(entry);
         }
     }
 
diff --git a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStdSessions.java b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStdSessions.java
index d00991434..c1cc1c507 100644
--- a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStdSessions.java
+++ b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStdSessions.java
@@ -133,7 +133,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
 
     @Override
     public synchronized void createTable(String... tables)
-                                         throws RocksDBException {
+            throws RocksDBException {
         this.checkValid();
 
         List<ColumnFamilyDescriptor> cfds = new ArrayList<>();
@@ -142,7 +142,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
                 continue;
             }
             ColumnFamilyDescriptor cfd = new ColumnFamilyDescriptor(
-                                         encode(table));
+                    encode(table));
             ColumnFamilyOptions options = cfd.getOptions();
             initOptions(this.config(), null, null, options, options);
             cfds.add(cfd);
@@ -468,7 +468,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
                 db.setEnableWriteThreadAdaptiveYield(true);
             }
             db.setInfoLogLevel(InfoLogLevel.valueOf(
-                conf.get(RocksDBOptions.LOG_LEVEL) + "_LEVEL"));
+                    conf.get(RocksDBOptions.LOG_LEVEL) + "_LEVEL"));
 
             db.setMaxSubcompactions(conf.get(RocksDBOptions.MAX_SUB_COMPACTIONS));
 
@@ -477,7 +477,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
 
             db.setUseDirectReads(conf.get(RocksDBOptions.USE_DIRECT_READS));
             db.setUseDirectIoForFlushAndCompaction(
-                conf.get(RocksDBOptions.USE_DIRECT_READS_WRITES_FC));
+                    conf.get(RocksDBOptions.USE_DIRECT_READS_WRITES_FC));
 
             db.setUseFsync(conf.get(RocksDBOptions.USE_FSYNC));
 
@@ -487,7 +487,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
 
             db.setSkipStatsUpdateOnDbOpen(conf.get(RocksDBOptions.SKIP_STATS_UPDATE_ON_DB_OPEN));
             db.setSkipCheckingSstFileSizesOnDbOpen(
-                conf.get(RocksDBOptions.SKIP_CHECK_SIZE_ON_DB_OPEN));
+                    conf.get(RocksDBOptions.SKIP_CHECK_SIZE_ON_DB_OPEN));
 
             db.setMaxFileOpeningThreads(conf.get(RocksDBOptions.MAX_FILE_OPENING_THREADS));
 
@@ -523,7 +523,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
             mdb.setCompactionReadaheadSize(conf.get(RocksDBOptions.COMPACTION_READAHEAD_SIZE));
 
             mdb.setDeleteObsoleteFilesPeriodMicros(
-                1000000 * conf.get(RocksDBOptions.DELETE_OBSOLETE_FILE_PERIOD));
+                    1000000 * conf.get(RocksDBOptions.DELETE_OBSOLETE_FILE_PERIOD));
         }
 
         if (cf != null) {
@@ -551,7 +551,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
 
             cf.setMinWriteBufferNumberToMerge(conf.get(RocksDBOptions.MIN_MEMTABLES_TO_MERGE));
             cf.setMaxWriteBufferNumberToMaintain(
-                conf.get(RocksDBOptions.MAX_MEMTABLES_TO_MAINTAIN));
+                    conf.get(RocksDBOptions.MAX_MEMTABLES_TO_MAINTAIN));
 
             cf.setInplaceUpdateSupport(conf.get(RocksDBOptions.MEMTABLE_INPLACE_UPDATE_SUPPORT));
 
@@ -584,15 +584,15 @@ public class RocksDBStdSessions extends RocksDBSessions {
             mcf.setTargetFileSizeMultiplier(conf.get(RocksDBOptions.TARGET_FILE_SIZE_MULTIPLIER));
 
             mcf.setLevel0FileNumCompactionTrigger(
-                conf.get(RocksDBOptions.LEVEL0_COMPACTION_TRIGGER));
+                    conf.get(RocksDBOptions.LEVEL0_COMPACTION_TRIGGER));
             mcf.setLevel0SlowdownWritesTrigger(
-                conf.get(RocksDBOptions.LEVEL0_SLOWDOWN_WRITES_TRIGGER));
+                    conf.get(RocksDBOptions.LEVEL0_SLOWDOWN_WRITES_TRIGGER));
             mcf.setLevel0StopWritesTrigger(conf.get(RocksDBOptions.LEVEL0_STOP_WRITES_TRIGGER));
 
             mcf.setSoftPendingCompactionBytesLimit(
-                conf.get(RocksDBOptions.SOFT_PENDING_COMPACTION_LIMIT));
+                    conf.get(RocksDBOptions.SOFT_PENDING_COMPACTION_LIMIT));
             mcf.setHardPendingCompactionBytesLimit(
-                conf.get(RocksDBOptions.HARD_PENDING_COMPACTION_LIMIT));
+                    conf.get(RocksDBOptions.HARD_PENDING_COMPACTION_LIMIT));
 
             /*
              * TODO: also set memtable options:
@@ -602,9 +602,9 @@ public class RocksDBStdSessions extends RocksDBSessions {
              * #diff-cde52d1fcbcce2bc6aae27838f1d3e7e9e469ccad8aaf8f2695f939e279d7501R369
              */
             mcf.setMemtablePrefixBloomSizeRatio(
-                conf.get(RocksDBOptions.MEMTABLE_BLOOM_SIZE_RATIO));
+                    conf.get(RocksDBOptions.MEMTABLE_BLOOM_SIZE_RATIO));
             mcf.setMemtableWholeKeyFiltering(
-                conf.get(RocksDBOptions.MEMTABLE_BLOOM_WHOLE_KEY_FILTERING));
+                    conf.get(RocksDBOptions.MEMTABLE_BLOOM_WHOLE_KEY_FILTERING));
             mcf.setMemtableHugePageSize(conf.get(RocksDBOptions.MEMTABL_BLOOM_HUGE_PAGE_SIZE));
 
             boolean bulkload = conf.get(RocksDBOptions.BULKLOAD_MODE);
@@ -648,7 +648,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
          */
         tableConfig.setDataBlockIndexType(conf.get(RocksDBOptions.DATA_BLOCK_SEARCH_TYPE));
         tableConfig.setDataBlockHashTableUtilRatio(
-            conf.get(RocksDBOptions.DATA_BLOCK_HASH_TABLE_RATIO));
+                conf.get(RocksDBOptions.DATA_BLOCK_HASH_TABLE_RATIO));
 
         long blockSize = conf.get(RocksDBOptions.BLOCK_SIZE);
         tableConfig.setBlockSize(blockSize);
@@ -674,9 +674,9 @@ public class RocksDBStdSessions extends RocksDBSessions {
             tableConfig.setWholeKeyFiltering(conf.get(RocksDBOptions.BLOOM_FILTER_WHOLE_KEY));
 
             tableConfig.setCacheIndexAndFilterBlocks(
-                conf.get(RocksDBOptions.CACHE_FILTER_AND_INDEX));
+                    conf.get(RocksDBOptions.CACHE_FILTER_AND_INDEX));
             tableConfig.setPinL0FilterAndIndexBlocksInCache(
-                conf.get(RocksDBOptions.PIN_L0_INDEX_AND_FILTER));
+                    conf.get(RocksDBOptions.PIN_L0_INDEX_AND_FILTER));
 
             // https://github.com/facebook/rocksdb/wiki/Partitioned-Index-Filters
             if (conf.get(RocksDBOptions.PARTITION_FILTERS_INDEXES)) {
@@ -686,7 +686,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
                            .setMetadataBlockSize(blockSize)
                            .setCacheIndexAndFilterBlocksWithHighPriority(true);
                 tableConfig.setPinTopLevelIndexAndFilter(
-                    conf.get(RocksDBOptions.PIN_TOP_INDEX_AND_FILTER));
+                        conf.get(RocksDBOptions.PIN_TOP_INDEX_AND_FILTER));
             }
         }
 
@@ -850,7 +850,7 @@ public class RocksDBStdSessions extends RocksDBSessions {
         /**
          * Merge a record to an existing key to a table
          * For more details about merge-operator:
-         *  <a href="https://github.com/facebook/rocksdb/wiki/merge-operator">...</a>
+         * <a href="https://github.com/facebook/rocksdb/wiki/merge-operator">...</a>
          */
         @Override
         public void merge(String table, byte[] key, byte[] value) {
diff --git a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStore.java b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStore.java
index c7aeb72b1..c34d9632f 100644
--- a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStore.java
+++ b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBStore.java
@@ -182,7 +182,7 @@ public abstract class RocksDBStore extends AbstractBackendStore<RocksDBSessions.
 
     protected List<String> tableNames(HugeType type) {
         return type != HugeType.OLAP ? Collections.singletonList(this.table(type).table()) :
-                                       this.olapTables();
+               this.olapTables();
     }
 
     @Override
@@ -758,7 +758,7 @@ public abstract class RocksDBStore extends AbstractBackendStore<RocksDBSessions.
             }
 
             for (Map.Entry<String, RocksDBSessions> entry :
-                snapshotPaths.entrySet()) {
+                    snapshotPaths.entrySet()) {
                 String snapshotPath = entry.getKey();
                 RocksDBSessions sessions = entry.getValue();
                 sessions.resumeSnapshot(snapshotPath);
diff --git a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBTable.java b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBTable.java
index 21d89b833..824986d22 100644
--- a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBTable.java
+++ b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdb/RocksDBTable.java
@@ -211,7 +211,7 @@ public class RocksDBTable extends BackendTable<RocksDBSessions.Session, BackendE
 
         // NOTE: this will lead to lazy create rocksdb iterator
         return BackendColumnIterator.wrap(new FlatMapperIterator<>(
-            ids.iterator(), id -> this.queryById(session, id)
+                ids.iterator(), id -> this.queryById(session, id)
         ));
     }
 
diff --git a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstSessions.java b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstSessions.java
index 786d50570..70eec3cc5 100644
--- a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstSessions.java
+++ b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstSessions.java
@@ -126,7 +126,7 @@ public class RocksDBSstSessions extends RocksDBSessions {
         }
     }
 
-    public void dropTable(String table) throws RocksDBException{
+    public void dropTable(String table) throws RocksDBException {
         try (SstFileWriter sst = this.tables.remove(table)) {
             assert sst == null || !sst.isOwningHandle() : "Please close table before drop to " +
                                                           "ensure call sst.finish()";
@@ -336,7 +336,7 @@ public class RocksDBSstSessions extends RocksDBSessions {
         /**
          * Merge a record to an existing key to a table
          * For more details about merge-operator:
-         *  <a href="https://github.com/facebook/rocksdb/wiki/merge-operator">...</a>
+         * <a href="https://github.com/facebook/rocksdb/wiki/merge-operator">...</a>
          */
         @Override
         public void merge(String table, byte[] key, byte[] value) {
diff --git a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstStore.java b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstStore.java
index 230bf68a0..d7b75610f 100644
--- a/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstStore.java
+++ b/hugegraph-server/hugegraph-rocksdb/src/main/java/org/apache/hugegraph/backend/store/rocksdbsst/RocksDBSstStore.java
@@ -39,7 +39,7 @@ public abstract class RocksDBSstStore extends RocksDBStore {
     protected RocksDBSessions openSessionPool(HugeConfig config,
                                               String dataPath, String walPath,
                                               List<String> tableNames)
-                                              throws RocksDBException {
+            throws RocksDBException {
         if (tableNames == null) {
             return new RocksDBSstSessions(config, this.database(), this.store(), dataPath);
         } else {
diff --git a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBMetrics.java b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBMetrics.java
index ba0af3630..77585c73a 100644
--- a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBMetrics.java
+++ b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBMetrics.java
@@ -20,7 +20,6 @@ package org.apache.hugegraph.backend.store.scylladb;
 import java.util.Map;
 
 import org.apache.cassandra.tools.NodeProbe;
-
 import org.apache.hugegraph.backend.store.cassandra.CassandraMetrics;
 import org.apache.hugegraph.backend.store.cassandra.CassandraSessionPool;
 import org.apache.hugegraph.config.HugeConfig;
diff --git a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBStoreProvider.java b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBStoreProvider.java
index 5ecccf2fe..015afb831 100644
--- a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBStoreProvider.java
+++ b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBStoreProvider.java
@@ -17,8 +17,6 @@
 
 package org.apache.hugegraph.backend.store.scylladb;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.store.BackendFeatures;
 import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.backend.store.BackendStoreProvider;
@@ -30,6 +28,7 @@ import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class ScyllaDBStoreProvider extends CassandraStoreProvider {
 
@@ -94,7 +93,7 @@ public class ScyllaDBStoreProvider extends CassandraStoreProvider {
     }
 
     public static class ScyllaDBSchemaStore
-                  extends CassandraStore.CassandraSchemaStore {
+            extends CassandraStore.CassandraSchemaStore {
 
         public ScyllaDBSchemaStore(BackendStoreProvider provider,
                                    String keyspace, String store) {
@@ -124,7 +123,7 @@ public class ScyllaDBStoreProvider extends CassandraStoreProvider {
     }
 
     public static class ScyllaDBGraphStore
-                  extends CassandraStore.CassandraGraphStore {
+            extends CassandraStore.CassandraGraphStore {
 
         public ScyllaDBGraphStore(BackendStoreProvider provider,
                                   String keyspace, String store) {
@@ -152,7 +151,7 @@ public class ScyllaDBStoreProvider extends CassandraStoreProvider {
     }
 
     public static class ScyllaDBSystemStore
-                  extends CassandraStore.CassandraSystemStore {
+            extends CassandraStore.CassandraSystemStore {
 
         public ScyllaDBSystemStore(BackendStoreProvider provider,
                                    String keyspace, String store) {
diff --git a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBTablesWithMV.java b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBTablesWithMV.java
index b4c30c764..61dfe88df 100644
--- a/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBTablesWithMV.java
+++ b/hugegraph-server/hugegraph-scylladb/src/main/java/org/apache/hugegraph/backend/store/scylladb/ScyllaDBTablesWithMV.java
@@ -29,6 +29,7 @@ import org.apache.hugegraph.backend.store.cassandra.CassandraTable;
 import org.apache.hugegraph.backend.store.cassandra.CassandraTables;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.type.define.HugeKeys;
+
 import com.datastax.driver.core.querybuilder.Select;
 
 public class ScyllaDBTablesWithMV {
@@ -62,17 +63,17 @@ public class ScyllaDBTablesWithMV {
     }
 
     private static void createSchemaIndexTable(
-                        CassandraSessionPool.Session session,
-                        String mvName, String table) {
+            CassandraSessionPool.Session session,
+            String mvName, String table) {
         final String NAME = CassandraTable.formatKey(HugeKeys.NAME);
         final String ID = CassandraTable.formatKey(HugeKeys.ID);
         String cql = String.format(
-                     "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
-                     "  SELECT * FROM %s " +
-                     "  WHERE %s IS NOT NULL " +
-                     "  PRIMARY KEY(%s, %s)",
-                     mvName, table, NAME,
-                     NAME, ID);
+                "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
+                "  SELECT * FROM %s " +
+                "  WHERE %s IS NOT NULL " +
+                "  PRIMARY KEY(%s, %s)",
+                mvName, table, NAME,
+                NAME, ID);
         session.execute(cql);
     }
 
@@ -206,11 +207,11 @@ public class ScyllaDBTablesWithMV {
             final String LABEL = CassandraTable.formatKey(HugeKeys.LABEL);
             final String ID = CassandraTable.formatKey(HugeKeys.ID);
             String cql = String.format(
-                         "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
-                         "  SELECT * FROM %s " +
-                         "  WHERE %s IS NOT NULL " +
-                         "  PRIMARY KEY(%s, %s)",
-                         mvLabel2Vertex, this.table(), LABEL, LABEL, ID);
+                    "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
+                    "  SELECT * FROM %s " +
+                    "  WHERE %s IS NOT NULL " +
+                    "  PRIMARY KEY(%s, %s)",
+                    mvLabel2Vertex, this.table(), LABEL, LABEL, ID);
             session.execute(cql);
         }
 
@@ -240,13 +241,13 @@ public class ScyllaDBTablesWithMV {
 
         private static final String LABEL = CassandraTable.formatKey(HugeKeys.LABEL);
         private final List<String> keys = this.idColumnName().stream()
-                                          .filter(k -> k != HugeKeys.LABEL)
-                                          .map(k -> CassandraTable.formatKey(k))
-                                          .collect(Collectors.toList());
+                                              .filter(k -> k != HugeKeys.LABEL)
+                                              .map(k -> CassandraTable.formatKey(k))
+                                              .collect(Collectors.toList());
         private final String prKeys = this.keys.stream()
-                                      .collect(Collectors.joining(","));
+                                               .collect(Collectors.joining(","));
         private final String prkeysNn = this.keys.stream().collect(
-                             Collectors.joining(" IS NOT NULL AND "));
+                Collectors.joining(" IS NOT NULL AND "));
 
         public Edge(String store, Directions direction) {
             super(store, direction);
@@ -257,13 +258,13 @@ public class ScyllaDBTablesWithMV {
                                    String indexLabel,
                                    HugeKeys column) {
             String cql = String.format(
-                         "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
-                         "  SELECT * FROM %s " +
-                         "  WHERE %s IS NOT NULL AND %s IS NOT NULL " +
-                         "  PRIMARY KEY(%s, %s)",
-                         mvLabel2Edge, this.table(),
-                         this.LABEL, this.prkeysNn,
-                         this.LABEL, this.prKeys);
+                    "CREATE MATERIALIZED VIEW IF NOT EXISTS %s AS " +
+                    "  SELECT * FROM %s " +
+                    "  WHERE %s IS NOT NULL AND %s IS NOT NULL " +
+                    "  PRIMARY KEY(%s, %s)",
+                    mvLabel2Edge, this.table(),
+                    LABEL, this.prkeysNn,
+                    LABEL, this.prKeys);
             session.execute(cql);
         }
 
diff --git a/hugegraph-server/hugegraph-test/pom.xml b/hugegraph-server/hugegraph-test/pom.xml
index 32dfad441..1bd869b5a 100644
--- a/hugegraph-server/hugegraph-test/pom.xml
+++ b/hugegraph-server/hugegraph-test/pom.xml
@@ -283,7 +283,7 @@
                             <finalName>microbenchmarks</finalName>
                             <transformers>
                                 <transformer
-                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <mainClass>org.openjdk.jmh.Main</mainClass>
                                 </transformer>
                             </transformers>
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ApiTestSuite.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ApiTestSuite.java
index 0f9041c13..11d3e6409 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ApiTestSuite.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ApiTestSuite.java
@@ -25,22 +25,22 @@ import org.junit.runners.Suite;
 
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
-    PropertyKeyApiTest.class,
-    VertexLabelApiTest.class,
-    EdgeLabelApiTest.class,
-    IndexLabelApiTest.class,
-    SchemaApiTest.class,
-    VertexApiTest.class,
-    EdgeApiTest.class,
-    TaskApiTest.class,
-    GremlinApiTest.class,
-    MetricsApiTest.class,
-    UserApiTest.class,
-    LoginApiTest.class,
-    ProjectApiTest.class,
-    TraversersApiTestSuite.class,
-    CypherApiTest.class,
-    ArthasApiTest.class
+        PropertyKeyApiTest.class,
+        VertexLabelApiTest.class,
+        EdgeLabelApiTest.class,
+        IndexLabelApiTest.class,
+        SchemaApiTest.class,
+        VertexApiTest.class,
+        EdgeApiTest.class,
+        TaskApiTest.class,
+        GremlinApiTest.class,
+        MetricsApiTest.class,
+        UserApiTest.class,
+        LoginApiTest.class,
+        ProjectApiTest.class,
+        TraversersApiTestSuite.class,
+        CypherApiTest.class,
+        ArthasApiTest.class
 })
 public class ApiTestSuite {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/BaseApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/BaseApiTest.java
index 9adf3bd7d..43b8cdbd1 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/BaseApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/BaseApiTest.java
@@ -108,11 +108,11 @@ public class BaseApiTest {
             this(url, true);
         }
 
-        public RestClient(String url,Boolean enableAuth) {
+        public RestClient(String url, Boolean enableAuth) {
             this.client = ClientBuilder.newClient();
             this.client.register(EncodingFilter.class);
             this.client.register(GZipEncoder.class);
-            if(enableAuth) {
+            if (enableAuth) {
                 this.client.register(HttpAuthenticationFeature.basic(USERNAME,
                                                                      PASSWORD));
             }
@@ -202,117 +202,117 @@ public class BaseApiTest {
         String path = URL_PREFIX + SCHEMA_PKS;
 
         createAndAssert(path, "{\n" +
-                "\"name\": \"name\",\n" +
-                "\"data_type\": \"TEXT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"name\",\n" +
+                              "\"data_type\": \"TEXT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"age\",\n" +
-                "\"data_type\": \"INT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"age\",\n" +
+                              "\"data_type\": \"INT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"city\",\n" +
-                "\"data_type\": \"TEXT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"city\",\n" +
+                              "\"data_type\": \"TEXT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"lang\",\n" +
-                "\"data_type\": \"TEXT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"lang\",\n" +
+                              "\"data_type\": \"TEXT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"date\",\n" +
-                "\"data_type\": \"TEXT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"date\",\n" +
+                              "\"data_type\": \"TEXT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"price\",\n" +
-                "\"data_type\": \"INT\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"price\",\n" +
+                              "\"data_type\": \"INT\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
         createAndAssert(path, "{\n" +
-                "\"name\": \"weight\",\n" +
-                "\"data_type\": \"DOUBLE\",\n" +
-                "\"cardinality\": \"SINGLE\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"properties\":[]\n" +
-                "}", 202);
+                              "\"name\": \"weight\",\n" +
+                              "\"data_type\": \"DOUBLE\",\n" +
+                              "\"cardinality\": \"SINGLE\",\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"properties\":[]\n" +
+                              "}", 202);
     }
 
     protected static void initVertexLabel() {
         String path = URL_PREFIX + SCHEMA_VLS;
 
         createAndAssert(path, "{\n" +
-                "\"primary_keys\":[\"name\"],\n" +
-                "\"id_strategy\": \"PRIMARY_KEY\",\n" +
-                "\"name\": \"person\",\n" +
-                "\"properties\":[\"city\", \"name\", \"age\"],\n" +
-                "\"check_exist\": false,\n" +
-                "\"nullable_keys\":[]\n" +
-                "}");
+                              "\"primary_keys\":[\"name\"],\n" +
+                              "\"id_strategy\": \"PRIMARY_KEY\",\n" +
+                              "\"name\": \"person\",\n" +
+                              "\"properties\":[\"city\", \"name\", \"age\"],\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"nullable_keys\":[]\n" +
+                              "}");
 
         createAndAssert(path, "{\n" +
-                "\"primary_keys\":[\"name\"],\n" +
-                "\"id_strategy\": \"PRIMARY_KEY\",\n" +
-                "\"name\": \"software\",\n" +
-                "\"properties\":[\"price\", \"name\", \"lang\"],\n" +
-                "\"check_exist\": false,\n" +
-                "\"nullable_keys\":[]\n" +
-                "}");
+                              "\"primary_keys\":[\"name\"],\n" +
+                              "\"id_strategy\": \"PRIMARY_KEY\",\n" +
+                              "\"name\": \"software\",\n" +
+                              "\"properties\":[\"price\", \"name\", \"lang\"],\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"nullable_keys\":[]\n" +
+                              "}");
     }
 
     protected static void initEdgeLabel() {
         String path = URL_PREFIX + SCHEMA_ELS;
 
         createAndAssert(path, "{\n" +
-                "\"name\": \"created\",\n" +
-                "\"source_label\": \"person\",\n" +
-                "\"target_label\": \"software\",\n" +
-                "\"frequency\": \"SINGLE\",\n" +
-                "\"properties\":[\"date\", \"weight\"],\n" +
-                "\"sort_keys\":[],\n" +
-                "\"check_exist\": false,\n" +
-                "\"nullable_keys\":[]\n" +
-                "}");
+                              "\"name\": \"created\",\n" +
+                              "\"source_label\": \"person\",\n" +
+                              "\"target_label\": \"software\",\n" +
+                              "\"frequency\": \"SINGLE\",\n" +
+                              "\"properties\":[\"date\", \"weight\"],\n" +
+                              "\"sort_keys\":[],\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"nullable_keys\":[]\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"name\": \"knows\",\n" +
-                "\"source_label\": \"person\",\n" +
-                "\"target_label\": \"person\",\n" +
-                "\"frequency\": \"MULTIPLE\",\n" +
-                "\"properties\":[\"date\", \"weight\"],\n" +
-                "\"sort_keys\":[\"date\"],\n" +
-                "\"check_exist\": false,\n" +
-                "\"nullable_keys\":[]\n" +
-                "}");
+                              "\"name\": \"knows\",\n" +
+                              "\"source_label\": \"person\",\n" +
+                              "\"target_label\": \"person\",\n" +
+                              "\"frequency\": \"MULTIPLE\",\n" +
+                              "\"properties\":[\"date\", \"weight\"],\n" +
+                              "\"sort_keys\":[\"date\"],\n" +
+                              "\"check_exist\": false,\n" +
+                              "\"nullable_keys\":[]\n" +
+                              "}");
     }
 
     protected static int initIndexLabel() {
         String path = URL_PREFIX + SCHEMA_ILS;
 
         Response r = client.post(path, "{\n" +
-                "\"name\": \"personByCity\",\n" +
-                "\"base_type\": \"VERTEX_LABEL\",\n" +
-                "\"base_value\": \"person\",\n" +
-                "\"index_type\": \"SECONDARY\",\n" +
-                "\"check_exist\": false,\n" +
-                "\"rebuild\": false,\n" +
-                "\"fields\": [\n" +
-                "\"city\"\n" +
-                "]\n" +
-                "}");
+                                       "\"name\": \"personByCity\",\n" +
+                                       "\"base_type\": \"VERTEX_LABEL\",\n" +
+                                       "\"base_value\": \"person\",\n" +
+                                       "\"index_type\": \"SECONDARY\",\n" +
+                                       "\"check_exist\": false,\n" +
+                                       "\"rebuild\": false,\n" +
+                                       "\"fields\": [\n" +
+                                       "\"city\"\n" +
+                                       "]\n" +
+                                       "}");
         String content = assertResponseStatus(202, r);
         return assertJsonContains(content, "task_id");
     }
@@ -378,59 +378,59 @@ public class BaseApiTest {
         String path = URL_PREFIX + GRAPH_VERTEX;
 
         createAndAssert(path, "{\n" +
-                "\"label\": \"person\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"marko\"," +
-                "\"age\": 29," +
-                "\"city\": \"Beijing\"" +
-                "}\n" +
-                "}");
+                              "\"label\": \"person\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"marko\"," +
+                              "\"age\": 29," +
+                              "\"city\": \"Beijing\"" +
+                              "}\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"label\": \"person\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"vadas\"," +
-                "\"age\": 27," +
-                "\"city\": \"HongKong\"" +
-                "}\n" +
-                "}");
+                              "\"label\": \"person\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"vadas\"," +
+                              "\"age\": 27," +
+                              "\"city\": \"HongKong\"" +
+                              "}\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"label\": \"person\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"josh\"," +
-                "\"age\": 32," +
-                "\"city\": \"Beijing\"" +
-                "}\n" +
-                "}");
+                              "\"label\": \"person\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"josh\"," +
+                              "\"age\": 32," +
+                              "\"city\": \"Beijing\"" +
+                              "}\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"label\": \"person\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"peter\"," +
-                "\"age\": 35," +
-                "\"city\": \"Shanghai\"" +
-                "}\n" +
-                "}");
+                              "\"label\": \"person\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"peter\"," +
+                              "\"age\": 35," +
+                              "\"city\": \"Shanghai\"" +
+                              "}\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"label\": \"software\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"ripple\"," +
-                "\"lang\": \"java\"," +
-                "\"price\": 199" +
-                "}\n" +
-                "}");
+                              "\"label\": \"software\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"ripple\"," +
+                              "\"lang\": \"java\"," +
+                              "\"price\": 199" +
+                              "}\n" +
+                              "}");
         createAndAssert(path, "{\n" +
-                "\"label\": \"software\",\n" +
-                "\"type\": \"vertex\",\n" +
-                "\"properties\":{" +
-                "\"name\": \"lop\"," +
-                "\"lang\": \"java\"," +
-                "\"price\": 328" +
-                "}\n" +
-                "}");
+                              "\"label\": \"software\",\n" +
+                              "\"type\": \"vertex\",\n" +
+                              "\"properties\":{" +
+                              "\"name\": \"lop\"," +
+                              "\"lang\": \"java\"," +
+                              "\"price\": 328" +
+                              "}\n" +
+                              "}");
     }
 
     protected static Response createAndAssert(String path, String body) {
@@ -480,7 +480,7 @@ public class BaseApiTest {
     }
 
     protected static String getVertexId(String label, String key, String value)
-                                        throws IOException {
+            throws IOException {
         String props = MAPPER.writeValueAsString(ImmutableMap.of(key, value));
         Map<String, Object> params = ImmutableMap.of(
                 "label", label,
@@ -588,14 +588,14 @@ public class BaseApiTest {
             JsonNode element = root.get(key);
             if (element == null) {
                 throw new HugeException(String.format(
-                          "Can't find value of the key: %s in json.", key));
+                        "Can't find value of the key: %s in json.", key));
             }
             JavaType type = MAPPER.getTypeFactory()
                                   .constructParametricType(List.class, clazz);
             return MAPPER.readValue(element.toString(), type);
         } catch (IOException e) {
             throw new HugeException(String.format(
-                      "Failed to deserialize %s", content), e);
+                    "Failed to deserialize %s", content), e);
         }
     }
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/CypherApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/CypherApiTest.java
index 4edd6b62b..3c3e3049f 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/CypherApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/CypherApiTest.java
@@ -47,7 +47,7 @@ public class CypherApiTest extends BaseApiTest {
     @Test
     public void testGet() {
         Map<String, Object> params = ImmutableMap.of("cypher", QUERY);
-        Response r =  client().get(PATH, params);
+        Response r = client().get(PATH, params);
 
         this.validStatusAndTextContains(QUERY_RESULT, r);
     }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeApiTest.java
index 9295293f6..6d9c65fee 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeApiTest.java
@@ -45,15 +45,15 @@ public class EdgeApiTest extends BaseApiTest {
         String inVId = getVertexId("software", "name", "lop");
 
         String edge = String.format("{" +
-                "\"label\": \"created\"," +
-                "\"outVLabel\": \"person\"," +
-                "\"inVLabel\": \"software\"," +
-                "\"outV\": \"%s\"," +
-                "\"inV\": \"%s\"," +
-                "\"properties\":{" +
-                "\"date\": \"20170324\"," +
-                "\"weight\": 0.5}" +
-                "}", outVId, inVId);
+                                    "\"label\": \"created\"," +
+                                    "\"outVLabel\": \"person\"," +
+                                    "\"inVLabel\": \"software\"," +
+                                    "\"outV\": \"%s\"," +
+                                    "\"inV\": \"%s\"," +
+                                    "\"properties\":{" +
+                                    "\"date\": \"20170324\"," +
+                                    "\"weight\": 0.5}" +
+                                    "}", outVId, inVId);
         Response r = client().post(PATH, edge);
         assertResponseStatus(201, r);
     }
@@ -64,15 +64,15 @@ public class EdgeApiTest extends BaseApiTest {
         String inVId = getVertexId("person", "name", "josh");
         // Create
         String edge = String.format("{" +
-                "\"label\": \"knows\"," +
-                "\"outVLabel\": \"person\"," +
-                "\"inVLabel\": \"person\"," +
-                "\"outV\": \"%s\"," +
-                "\"inV\": \"%s\"," +
-                "\"properties\":{" +
-                "\"date\": \"2013-02-20\"," +
-                "\"weight\": 1.0}" +
-                "}", outVId, inVId);
+                                    "\"label\": \"knows\"," +
+                                    "\"outVLabel\": \"person\"," +
+                                    "\"inVLabel\": \"person\"," +
+                                    "\"outV\": \"%s\"," +
+                                    "\"inV\": \"%s\"," +
+                                    "\"properties\":{" +
+                                    "\"date\": \"2013-02-20\"," +
+                                    "\"weight\": 1.0}" +
+                                    "}", outVId, inVId);
         Response r = client().post(PATH, edge);
         // The edge id is 'S1:marko>1>7JooBil0>S1:josh'
         String content = assertResponseStatus(201, r);
@@ -80,56 +80,56 @@ public class EdgeApiTest extends BaseApiTest {
 
         // Update edge with edgeId
         edge = String.format("{" +
-                "\"edges\":[" +
-                "{" +
-                "\"id\":\"%s\"," +
-                "\"label\":\"knows\"," +
-                "\"outV\":\"%s\"," +
-                "\"outVLabel\":\"person\"," +
-                "\"inV\":\"%s\"," +
-                "\"inVLabel\":\"person\"," +
-                "\"properties\":{" +
-                "\"weight\":0.2," +
-                "\"date\":\"2014-02-20\"" +
-                "}" +
-                "}" +
-                "]," +
-                "\"update_strategies\":{" +
-                "\"weight\":\"SUM\"," +
-                "\"date\":\"BIGGER\"" +
-                "}," +
-                "\"check_vertex\":false," +
-                "\"create_if_not_exist\":true" +
-                "}", edgeId, outVId, inVId);
+                             "\"edges\":[" +
+                             "{" +
+                             "\"id\":\"%s\"," +
+                             "\"label\":\"knows\"," +
+                             "\"outV\":\"%s\"," +
+                             "\"outVLabel\":\"person\"," +
+                             "\"inV\":\"%s\"," +
+                             "\"inVLabel\":\"person\"," +
+                             "\"properties\":{" +
+                             "\"weight\":0.2," +
+                             "\"date\":\"2014-02-20\"" +
+                             "}" +
+                             "}" +
+                             "]," +
+                             "\"update_strategies\":{" +
+                             "\"weight\":\"SUM\"," +
+                             "\"date\":\"BIGGER\"" +
+                             "}," +
+                             "\"check_vertex\":false," +
+                             "\"create_if_not_exist\":true" +
+                             "}", edgeId, outVId, inVId);
         r = client().put(PATH, "batch", edge, ImmutableMap.of());
         // Now allowed to modify sortkey values, the property 'date' has changed
         content = assertResponseStatus(400, r);
         Assert.assertTrue(content.contains(
-                          "either be null or equal to the origin value when " +
-                          "specified edge id"));
+                "either be null or equal to the origin value when " +
+                "specified edge id"));
 
         // Update edge without edgeId
         edge = String.format("{" +
-                "\"edges\":[" +
-                "{" +
-                "\"label\":\"knows\"," +
-                "\"outV\":\"%s\"," +
-                "\"outVLabel\":\"person\"," +
-                "\"inV\":\"%s\"," +
-                "\"inVLabel\":\"person\"," +
-                "\"properties\":{" +
-                "\"weight\":0.2," +
-                "\"date\":\"2014-02-20\"" +
-                "}" +
-                "}" +
-                "]," +
-                "\"update_strategies\":{" +
-                "\"weight\":\"SUM\"," +
-                "\"date\":\"BIGGER\"" +
-                "}," +
-                "\"check_vertex\":false," +
-                "\"create_if_not_exist\":true" +
-                "}", outVId, inVId);
+                             "\"edges\":[" +
+                             "{" +
+                             "\"label\":\"knows\"," +
+                             "\"outV\":\"%s\"," +
+                             "\"outVLabel\":\"person\"," +
+                             "\"inV\":\"%s\"," +
+                             "\"inVLabel\":\"person\"," +
+                             "\"properties\":{" +
+                             "\"weight\":0.2," +
+                             "\"date\":\"2014-02-20\"" +
+                             "}" +
+                             "}" +
+                             "]," +
+                             "\"update_strategies\":{" +
+                             "\"weight\":\"SUM\"," +
+                             "\"date\":\"BIGGER\"" +
+                             "}," +
+                             "\"check_vertex\":false," +
+                             "\"create_if_not_exist\":true" +
+                             "}", outVId, inVId);
         r = client().put(PATH, "batch", edge, ImmutableMap.of());
         // Add a new edge when sortkey value has changed
         content = assertResponseStatus(200, r);
@@ -143,15 +143,15 @@ public class EdgeApiTest extends BaseApiTest {
         String inVId = getVertexId("software", "name", "lop");
 
         String edge = String.format("{" +
-                "\"label\": \"created\"," +
-                "\"outVLabel\": \"person\"," +
-                "\"inVLabel\": \"software\"," +
-                "\"outV\": \"%s\"," +
-                "\"inV\": \"%s\"," +
-                "\"properties\":{" +
-                "\"date\": \"20170324\"," +
-                "\"weight\": 0.5}" +
-                "}", outVId, inVId);
+                                    "\"label\": \"created\"," +
+                                    "\"outVLabel\": \"person\"," +
+                                    "\"inVLabel\": \"software\"," +
+                                    "\"outV\": \"%s\"," +
+                                    "\"inV\": \"%s\"," +
+                                    "\"properties\":{" +
+                                    "\"date\": \"20170324\"," +
+                                    "\"weight\": 0.5}" +
+                                    "}", outVId, inVId);
         Response r = client().post(PATH, edge);
         String content = assertResponseStatus(201, r);
 
@@ -166,15 +166,15 @@ public class EdgeApiTest extends BaseApiTest {
         String inVId = getVertexId("software", "name", "lop");
 
         String edge = String.format("{" +
-                "\"label\": \"created\"," +
-                "\"outVLabel\": \"person\"," +
-                "\"inVLabel\": \"software\"," +
-                "\"outV\": \"%s\"," +
-                "\"inV\": \"%s\"," +
-                "\"properties\":{" +
-                "\"date\": \"20170324\"," +
-                "\"weight\": 0.5}" +
-                "}", outVId, inVId);
+                                    "\"label\": \"created\"," +
+                                    "\"outVLabel\": \"person\"," +
+                                    "\"inVLabel\": \"software\"," +
+                                    "\"outV\": \"%s\"," +
+                                    "\"inV\": \"%s\"," +
+                                    "\"properties\":{" +
+                                    "\"date\": \"20170324\"," +
+                                    "\"weight\": 0.5}" +
+                                    "}", outVId, inVId);
         Response r = client().post(PATH, edge);
         assertResponseStatus(201, r);
 
@@ -188,15 +188,15 @@ public class EdgeApiTest extends BaseApiTest {
         String inVId = getVertexId("software", "name", "lop");
 
         String edge = String.format("{" +
-                "\"label\": \"created\"," +
-                "\"outVLabel\": \"person\"," +
-                "\"inVLabel\": \"software\"," +
-                "\"outV\": \"%s\"," +
-                "\"inV\": \"%s\"," +
-                "\"properties\":{" +
-                "\"date\": \"20170324\"," +
-                "\"weight\": 0.5}" +
-                "}", outVId, inVId);
+                                    "\"label\": \"created\"," +
+                                    "\"outVLabel\": \"person\"," +
+                                    "\"inVLabel\": \"software\"," +
+                                    "\"outV\": \"%s\"," +
+                                    "\"inV\": \"%s\"," +
+                                    "\"properties\":{" +
+                                    "\"date\": \"20170324\"," +
+                                    "\"weight\": 0.5}" +
+                                    "}", outVId, inVId);
         Response r = client().post(PATH, edge);
         String content = assertResponseStatus(201, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeLabelApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeLabelApiTest.java
index 434fae824..2a9e85b3a 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeLabelApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/EdgeLabelApiTest.java
@@ -39,14 +39,14 @@ public class EdgeLabelApiTest extends BaseApiTest {
     @Test
     public void testCreate() {
         String edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": \"person\"," +
-                "\"target_label\": \"software\"," +
-                "\"frequency\": \"SINGLE\"," +
-                "\"properties\":[\"date\", \"city\"]," +
-                "\"nullable_keys\":[\"city\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                           "\"name\": \"created\"," +
+                           "\"source_label\": \"person\"," +
+                           "\"target_label\": \"software\"," +
+                           "\"frequency\": \"SINGLE\"," +
+                           "\"properties\":[\"date\", \"city\"]," +
+                           "\"nullable_keys\":[\"city\"]," +
+                           "\"sort_keys\":[]" +
+                           "}";
         Response r = client().post(PATH, edgeLabel);
         assertResponseStatus(201, r);
     }
@@ -54,26 +54,26 @@ public class EdgeLabelApiTest extends BaseApiTest {
     @Test
     public void testAppend() {
         String edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": \"person\"," +
-                "\"target_label\": \"software\"," +
-                "\"frequency\": \"SINGLE\"," +
-                "\"properties\":[\"date\", \"city\"]," +
-                "\"nullable_keys\":[\"city\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                           "\"name\": \"created\"," +
+                           "\"source_label\": \"person\"," +
+                           "\"target_label\": \"software\"," +
+                           "\"frequency\": \"SINGLE\"," +
+                           "\"properties\":[\"date\", \"city\"]," +
+                           "\"nullable_keys\":[\"city\"]," +
+                           "\"sort_keys\":[]" +
+                           "}";
         Response r = client().post(PATH, edgeLabel);
         assertResponseStatus(201, r);
 
         edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": null," +
-                "\"target_label\": null," +
-                "\"frequency\": \"DEFAULT\"," +
-                "\"properties\":[\"lang\"]," +
-                "\"nullable_keys\":[\"lang\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                    "\"name\": \"created\"," +
+                    "\"source_label\": null," +
+                    "\"target_label\": null," +
+                    "\"frequency\": \"DEFAULT\"," +
+                    "\"properties\":[\"lang\"]," +
+                    "\"nullable_keys\":[\"lang\"]," +
+                    "\"sort_keys\":[]" +
+                    "}";
         Map<String, Object> params = ImmutableMap.of("action", "append");
         r = client().put(PATH, "created", edgeLabel, params);
         assertResponseStatus(200, r);
@@ -82,14 +82,14 @@ public class EdgeLabelApiTest extends BaseApiTest {
     @Test
     public void testGet() {
         String edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": \"person\"," +
-                "\"target_label\": \"software\"," +
-                "\"frequency\": \"SINGLE\"," +
-                "\"properties\":[\"date\", \"city\"]," +
-                "\"nullable_keys\":[\"city\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                           "\"name\": \"created\"," +
+                           "\"source_label\": \"person\"," +
+                           "\"target_label\": \"software\"," +
+                           "\"frequency\": \"SINGLE\"," +
+                           "\"properties\":[\"date\", \"city\"]," +
+                           "\"nullable_keys\":[\"city\"]," +
+                           "\"sort_keys\":[]" +
+                           "}";
         Response r = client().post(PATH, edgeLabel);
         assertResponseStatus(201, r);
 
@@ -101,14 +101,14 @@ public class EdgeLabelApiTest extends BaseApiTest {
     @Test
     public void testList() {
         String edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": \"person\"," +
-                "\"target_label\": \"software\"," +
-                "\"frequency\": \"SINGLE\"," +
-                "\"properties\":[\"date\", \"city\"]," +
-                "\"nullable_keys\":[\"city\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                           "\"name\": \"created\"," +
+                           "\"source_label\": \"person\"," +
+                           "\"target_label\": \"software\"," +
+                           "\"frequency\": \"SINGLE\"," +
+                           "\"properties\":[\"date\", \"city\"]," +
+                           "\"nullable_keys\":[\"city\"]," +
+                           "\"sort_keys\":[]" +
+                           "}";
         Response r = client().post(PATH, edgeLabel);
         assertResponseStatus(201, r);
 
@@ -119,14 +119,14 @@ public class EdgeLabelApiTest extends BaseApiTest {
     @Test
     public void testDelete() {
         String edgeLabel = "{" +
-                "\"name\": \"created\"," +
-                "\"source_label\": \"person\"," +
-                "\"target_label\": \"software\"," +
-                "\"frequency\": \"SINGLE\"," +
-                "\"properties\":[\"date\", \"city\"]," +
-                "\"nullable_keys\":[\"city\"]," +
-                "\"sort_keys\":[]" +
-                "}";
+                           "\"name\": \"created\"," +
+                           "\"source_label\": \"person\"," +
+                           "\"target_label\": \"software\"," +
+                           "\"frequency\": \"SINGLE\"," +
+                           "\"properties\":[\"date\", \"city\"]," +
+                           "\"nullable_keys\":[\"city\"]," +
+                           "\"sort_keys\":[]" +
+                           "}";
         Response r = client().post(PATH, edgeLabel);
         assertResponseStatus(201, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/GremlinApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/GremlinApiTest.java
index e9f2c7388..612914177 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/GremlinApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/GremlinApiTest.java
@@ -20,14 +20,14 @@ package org.apache.hugegraph.api;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
-
+import org.apache.hugegraph.testutil.Assert;
 import org.junit.Assume;
 import org.junit.Test;
 
-import org.apache.hugegraph.testutil.Assert;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class GremlinApiTest extends BaseApiTest {
 
     private static String path = "/gremlin";
@@ -35,17 +35,17 @@ public class GremlinApiTest extends BaseApiTest {
     @Test
     public void testPost() {
         String body = "{" +
-                "\"gremlin\":\"g.V()\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                      "\"gremlin\":\"g.V()\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
     }
 
     @Test
     public void testGet() {
         Map<String, Object> params = ImmutableMap.of("gremlin",
-                                     "hugegraph.traversal().V()");
+                                                     "hugegraph.traversal().V()");
         Response r = client().get(path, params);
         Assert.assertEquals(r.readEntity(String.class), 200, r.getStatus());
     }
@@ -53,29 +53,30 @@ public class GremlinApiTest extends BaseApiTest {
     @Test
     public void testScript() {
         String bodyTemplate = "{" +
-                "\"gremlin\":\"%s\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                              "\"gremlin\":\"%s\"," +
+                              "\"bindings\":{}," +
+                              "\"language\":\"gremlin-groovy\"," +
+                              "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
 
         String script = "schema=hugegraph.schema();" +
-                "schema.propertyKey('name').asText().ifNotExist().create();" +
-                "schema.propertyKey('age').asInt().ifNotExist().create();" +
-                "schema.propertyKey('city').asUUID().ifNotExist().create();" +
-                "schema.propertyKey('lang').asText().ifNotExist().create();" +
-                "schema.propertyKey('date').asText().ifNotExist().create();" +
-                "schema.propertyKey('price').asInt().ifNotExist().create();" +
-                "person=schema.vertexLabel('person').properties('name','age','city')." +
-                "useCustomizeUuidId().ifNotExist().create();" +
-                "knows=schema.edgeLabel('knows').sourceLabel('person').targetLabel('person')." +
-                "properties('date').ifNotExist().create();" +
-                "marko=hugegraph.addVertex(T.id,'835e1153928149578691cf79258e90eb'" +
-                ",T.label,'person','name','marko','age',29," +
-                "'city','135e1153928149578691cf79258e90eb');" +
-                "vadas=hugegraph.addVertex(T.id,'935e1153928149578691cf79258e90eb'" +
-                ",T.label,'person','name','vadas','age',27," +
-                "'city','235e1153928149578691cf79258e90eb');" +
-                "marko.addEdge('knows',vadas,'date','20160110');";
+                        "schema.propertyKey('name').asText().ifNotExist().create();" +
+                        "schema.propertyKey('age').asInt().ifNotExist().create();" +
+                        "schema.propertyKey('city').asUUID().ifNotExist().create();" +
+                        "schema.propertyKey('lang').asText().ifNotExist().create();" +
+                        "schema.propertyKey('date').asText().ifNotExist().create();" +
+                        "schema.propertyKey('price').asInt().ifNotExist().create();" +
+                        "person=schema.vertexLabel('person').properties('name','age','city')." +
+                        "useCustomizeUuidId().ifNotExist().create();" +
+                        "knows=schema.edgeLabel('knows').sourceLabel('person').targetLabel" +
+                        "('person')." +
+                        "properties('date').ifNotExist().create();" +
+                        "marko=hugegraph.addVertex(T.id,'835e1153928149578691cf79258e90eb'" +
+                        ",T.label,'person','name','marko','age',29," +
+                        "'city','135e1153928149578691cf79258e90eb');" +
+                        "vadas=hugegraph.addVertex(T.id,'935e1153928149578691cf79258e90eb'" +
+                        ",T.label,'person','name','vadas','age',27," +
+                        "'city','235e1153928149578691cf79258e90eb');" +
+                        "marko.addEdge('knows',vadas,'date','20160110');";
         String body = String.format(bodyTemplate, script);
         assertResponseStatus(200, client().post(path, body));
 
@@ -91,51 +92,51 @@ public class GremlinApiTest extends BaseApiTest {
     @Test
     public void testClearAndInit() {
         String body = "{" +
-                "\"gremlin\":\"hugegraph.backendStoreFeatures()" +
-                "                       .supportsSharedStorage();\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                      "\"gremlin\":\"hugegraph.backendStoreFeatures()" +
+                      "                       .supportsSharedStorage();\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         String content = assertResponseStatus(200, client().post(path, body));
         Map<?, ?> result = assertJsonContains(content, "result");
-        @SuppressWarnings({ "unchecked" })
+        @SuppressWarnings({"unchecked"})
         Object data = ((List<Object>) assertMapContains(result, "data")).get(0);
         boolean supportsSharedStorage = (boolean) data;
         Assume.assumeTrue("Can't clear non-shared-storage backend",
                           supportsSharedStorage);
 
         body = "{" +
-                "\"gremlin\":\"" +
-                "  if (!hugegraph.backendStoreFeatures()" +
-                "                .supportsSharedStorage())" +
-                "    return;" +
-                "  def auth = hugegraph.hugegraph().authManager();" +
-                "  def admin = auth.findUser('admin');" +
-                "  hugegraph.clearBackend();" +
-                "  hugegraph.initBackend();" +
-                "  auth.createUser(admin);\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+               "\"gremlin\":\"" +
+               "  if (!hugegraph.backendStoreFeatures()" +
+               "                .supportsSharedStorage())" +
+               "    return;" +
+               "  def auth = hugegraph.hugegraph().authManager();" +
+               "  def admin = auth.findUser('admin');" +
+               "  hugegraph.clearBackend();" +
+               "  hugegraph.initBackend();" +
+               "  auth.createUser(admin);\"," +
+               "\"bindings\":{}," +
+               "\"language\":\"gremlin-groovy\"," +
+               "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
 
         body = "{" +
-                "\"gremlin\":\"hugegraph.serverStarted(" +
-                "              GlobalMasterInfo.master('server1'))\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+               "\"gremlin\":\"hugegraph.serverStarted(" +
+               "              GlobalMasterInfo.master('server1'))\"," +
+               "\"bindings\":{}," +
+               "\"language\":\"gremlin-groovy\"," +
+               "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
     }
 
     @Test
     public void testTruncate() {
         String body = "{" +
-                "\"gremlin\":\"try {hugegraph.truncateBackend()} " +
-                "catch (UnsupportedOperationException e) {}\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                      "\"gremlin\":\"try {hugegraph.truncateBackend()} " +
+                      "catch (UnsupportedOperationException e) {}\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
     }
 
@@ -144,78 +145,78 @@ public class GremlinApiTest extends BaseApiTest {
         String pkPath = "/graphs/hugegraph/schema/propertykeys/";
         // Cardinality single
         String foo = "{" +
-                "\"name\": \"foo\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"SINGLE\"," +
-                "\"properties\":[]" +
-                "}";
+                     "\"name\": \"foo\"," +
+                     "\"data_type\": \"TEXT\"," +
+                     "\"cardinality\": \"SINGLE\"," +
+                     "\"properties\":[]" +
+                     "}";
         assertResponseStatus(202, client().post(pkPath, foo));
         // Cardinality list
         String bar = "{" +
-                "\"name\": \"bar\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"LIST\"," +
-                "\"properties\":[]" +
-                "}";
+                     "\"name\": \"bar\"," +
+                     "\"data_type\": \"TEXT\"," +
+                     "\"cardinality\": \"LIST\"," +
+                     "\"properties\":[]" +
+                     "}";
         assertResponseStatus(202, client().post(pkPath, bar));
 
         String vlPath = "/graphs/hugegraph/schema/vertexlabels/";
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"CUSTOMIZE_STRING\"," +
-                "\"properties\": [\"foo\", \"bar\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"CUSTOMIZE_STRING\"," +
+                             "\"properties\": [\"foo\", \"bar\"]" +
+                             "}";
         assertResponseStatus(201, client().post(vlPath, vertexLabel));
 
         // Not supply cardinality
         String body = "{" +
-                "\"gremlin\":\"g.addV('person').property(T.id, '1')" +
-                ".property('foo', '123').property('bar', '123')\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                      "\"gremlin\":\"g.addV('person').property(T.id, '1')" +
+                      ".property('foo', '123').property('bar', '123')\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
 
         // Supply matched cardinality
         body = "{\"gremlin\":\"g.addV('person').property(T.id, '1')" +
-                ".property(single, 'foo', '123')" +
-                ".property(list, 'bar', '123')\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+               ".property(single, 'foo', '123')" +
+               ".property(list, 'bar', '123')\"," +
+               "\"bindings\":{}," +
+               "\"language\":\"gremlin-groovy\"," +
+               "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
 
         // Supply unmatch cardinality
         body = "{\"gremlin\":\"g.addV('person').property(T.id, '1')" +
-                ".property(list, 'foo', '123')" +
-                ".property(list, 'bar', '123')\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+               ".property(list, 'foo', '123')" +
+               ".property(list, 'bar', '123')\"," +
+               "\"bindings\":{}," +
+               "\"language\":\"gremlin-groovy\"," +
+               "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(400, client().post(path, body));
 
         // NOTE: supply unmatch cardinality, but we give up the check
         body = "{\"gremlin\":\"g.addV('person').property(T.id, '1')" +
-                ".property(single, 'foo', '123')" +
-                ".property(single, 'bar', '123')\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+               ".property(single, 'foo', '123')" +
+               ".property(single, 'bar', '123')\"," +
+               "\"bindings\":{}," +
+               "\"language\":\"gremlin-groovy\"," +
+               "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         assertResponseStatus(200, client().post(path, body));
     }
 
     @Test
     public void testFileSerialize() {
         String body = "{" +
-                "\"gremlin\":\"File file = new File('test.text')\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
+                      "\"gremlin\":\"File file = new File('test.text')\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{\"g\":\"__g_hugegraph\"}}";
         Response r = client().post(path, body);
         String content = r.readEntity(String.class);
         Assert.assertTrue(content, r.getStatus() == 200);
         Map<?, ?> result = assertJsonContains(content, "result");
-        @SuppressWarnings({ "unchecked", "rawtypes" })
+        @SuppressWarnings({"unchecked", "rawtypes"})
         Map data = ((List<Map>) assertMapContains(result, "data")).get(0);
         Assert.assertEquals("test.text", data.get("file"));
     }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/IndexLabelApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/IndexLabelApiTest.java
index 37a14bb91..5b232c5e1 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/IndexLabelApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/IndexLabelApiTest.java
@@ -40,12 +40,12 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testCreate() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]" +
+                            "}";
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
     }
@@ -53,23 +53,23 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testAppend() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]" +
+                            "}";
 
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
 
         indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"user_data\": {" +
-                "\"min\": 0," +
-                "\"max\": 100" +
-                "}" +
-                "}";
+                     "\"name\": \"personByAge\"," +
+                     "\"user_data\": {" +
+                     "\"min\": 0," +
+                     "\"max\": 100" +
+                     "}" +
+                     "}";
         Map<String, Object> params = ImmutableMap.of("action", "append");
         r = client().put(PATH, "personByAge", indexLabel, params);
         assertResponseStatus(200, r);
@@ -78,25 +78,25 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testEliminate() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]," +
-                "\"user_data\": {" +
-                "\"min\": 0," +
-                "\"max\": 100" +
-                "}" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]," +
+                            "\"user_data\": {" +
+                            "\"min\": 0," +
+                            "\"max\": 100" +
+                            "}" +
+                            "}";
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
 
         indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"user_data\": {" +
-                "\"min\": 0" +
-                "}" +
-                "}";
+                     "\"name\": \"personByAge\"," +
+                     "\"user_data\": {" +
+                     "\"min\": 0" +
+                     "}" +
+                     "}";
         Map<String, Object> params = ImmutableMap.of("action", "eliminate");
         r = client().put(PATH, "personByAge", indexLabel, params);
         assertResponseStatus(200, r);
@@ -105,12 +105,12 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testGet() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]" +
+                            "}";
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
 
@@ -122,12 +122,12 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testList() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]" +
+                            "}";
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
 
@@ -138,12 +138,12 @@ public class IndexLabelApiTest extends BaseApiTest {
     @Test
     public void testDelete() {
         String indexLabel = "{" +
-                "\"name\": \"personByAge\"," +
-                "\"base_type\": \"VERTEX_LABEL\"," +
-                "\"base_value\": \"person\"," +
-                "\"index_type\": \"RANGE\"," +
-                "\"fields\":[\"age\"]" +
-                "}";
+                            "\"name\": \"personByAge\"," +
+                            "\"base_type\": \"VERTEX_LABEL\"," +
+                            "\"base_value\": \"person\"," +
+                            "\"index_type\": \"RANGE\"," +
+                            "\"fields\":[\"age\"]" +
+                            "}";
         Response r = client().post(PATH, indexLabel);
         assertResponseStatus(202, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/LoginApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/LoginApiTest.java
index 6b4563cd5..b323efa36 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/LoginApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/LoginApiTest.java
@@ -42,7 +42,8 @@ public class LoginApiTest extends BaseApiTest {
     @Before
     public void setup() {
         Response r = this.createUser("test", "test");
-        Map<String, Object> user = r.readEntity(new GenericType<Map<String, Object>>(){});
+        Map<String, Object> user = r.readEntity(new GenericType<Map<String, Object>>() {
+        });
         this.userId4Test = (String) user.get("id");
     }
 
@@ -115,7 +116,8 @@ public class LoginApiTest extends BaseApiTest {
         assertJsonContains(result, "user_name");
 
         Map<String, Object> user = JsonUtil.fromJson(result,
-                                                     new TypeReference<Map<String, Object>>(){});
+                                                     new TypeReference<Map<String, Object>>() {
+                                                     });
         Assert.assertEquals(this.userId4Test, user.get("user_id"));
         Assert.assertEquals("test", user.get("user_name"));
 
@@ -157,7 +159,8 @@ public class LoginApiTest extends BaseApiTest {
 
     private String tokenFromResponse(String content) {
         Map<String, Object> data = JsonUtil.fromJson(content,
-                                                     new TypeReference<Map<String, Object>>(){});
+                                                     new TypeReference<Map<String, Object>>() {
+                                                     });
         return (String) data.get("token");
     }
 }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ProjectApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ProjectApiTest.java
index 8c2b1ad89..e48f9f50a 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ProjectApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/ProjectApiTest.java
@@ -206,11 +206,11 @@ public class ProjectApiTest extends BaseApiTest {
             Assert.assertEquals(desc, description);
         }
         Assert.assertFalse(StringUtils.isEmpty(
-            assertJsonContains(respBody, "project_target")));
+                assertJsonContains(respBody, "project_target")));
         Assert.assertFalse(StringUtils.isEmpty(
-            assertJsonContains(respBody, "project_admin_group")));
+                assertJsonContains(respBody, "project_admin_group")));
         Assert.assertFalse(StringUtils.isEmpty(
-            assertJsonContains(respBody, "project_op_group")));
+                assertJsonContains(respBody, "project_op_group")));
         return respBody;
     }
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/PropertyKeyApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/PropertyKeyApiTest.java
index 0b2531866..662a643b1 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/PropertyKeyApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/PropertyKeyApiTest.java
@@ -29,11 +29,11 @@ public class PropertyKeyApiTest extends BaseApiTest {
     @Test
     public void testCreate() {
         String propertyKey = "{" +
-                "\"name\": \"id\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"SINGLE\"," +
-                "\"properties\":[]" +
-                "}";
+                             "\"name\": \"id\"," +
+                             "\"data_type\": \"TEXT\"," +
+                             "\"cardinality\": \"SINGLE\"," +
+                             "\"properties\":[]" +
+                             "}";
         Response r = client().post(PATH, propertyKey);
         assertResponseStatus(202, r);
     }
@@ -41,11 +41,11 @@ public class PropertyKeyApiTest extends BaseApiTest {
     @Test
     public void testGet() {
         String propertyKey = "{" +
-                "\"name\": \"id\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"SINGLE\"," +
-                "\"properties\":[]" +
-                "}";
+                             "\"name\": \"id\"," +
+                             "\"data_type\": \"TEXT\"," +
+                             "\"cardinality\": \"SINGLE\"," +
+                             "\"properties\":[]" +
+                             "}";
         Response r = client().post(PATH, propertyKey);
         assertResponseStatus(202, r);
 
@@ -57,11 +57,11 @@ public class PropertyKeyApiTest extends BaseApiTest {
     @Test
     public void testList() {
         String propertyKey = "{" +
-                "\"name\": \"id\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"SINGLE\"," +
-                "\"properties\":[]" +
-                "}";
+                             "\"name\": \"id\"," +
+                             "\"data_type\": \"TEXT\"," +
+                             "\"cardinality\": \"SINGLE\"," +
+                             "\"properties\":[]" +
+                             "}";
         Response r = client().post(PATH, propertyKey);
         assertResponseStatus(202, r);
 
@@ -72,11 +72,11 @@ public class PropertyKeyApiTest extends BaseApiTest {
     @Test
     public void testDelete() {
         String propertyKey = "{" +
-                "\"name\": \"id\"," +
-                "\"data_type\": \"TEXT\"," +
-                "\"cardinality\": \"SINGLE\"," +
-                "\"properties\":[]" +
-                "}";
+                             "\"name\": \"id\"," +
+                             "\"data_type\": \"TEXT\"," +
+                             "\"cardinality\": \"SINGLE\"," +
+                             "\"properties\":[]" +
+                             "}";
         Response r = client().post(PATH, propertyKey);
         assertResponseStatus(202, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/TaskApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/TaskApiTest.java
index 322adb4db..3800ebb30 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/TaskApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/TaskApiTest.java
@@ -137,17 +137,17 @@ public class TaskApiTest extends BaseApiTest {
         String rebuildPath = "/graphs/hugegraph/jobs/rebuild/indexlabels";
         String personByCity = "personByCity";
         Map<String, Object> params = ImmutableMap.of();
-        Response r = client().put(rebuildPath, personByCity, "",  params);
+        Response r = client().put(rebuildPath, personByCity, "", params);
         String content = assertResponseStatus(202, r);
         return assertJsonContains(content, "task_id");
     }
 
     private int gremlinJob() {
         String body = "{" +
-                "\"gremlin\":\"Thread.sleep(1000L)\"," +
-                "\"bindings\":{}," +
-                "\"language\":\"gremlin-groovy\"," +
-                "\"aliases\":{}}";
+                      "\"gremlin\":\"Thread.sleep(1000L)\"," +
+                      "\"bindings\":{}," +
+                      "\"language\":\"gremlin-groovy\"," +
+                      "\"aliases\":{}}";
         String path = "/graphs/hugegraph/jobs/gremlin";
         String content = assertResponseStatus(201, client().post(path, body));
         return assertJsonContains(content, "task_id");
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/UserApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/UserApiTest.java
index eef8395f9..da189cd1a 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/UserApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/UserApiTest.java
@@ -43,8 +43,9 @@ public class UserApiTest extends BaseApiTest {
         Response r = this.client().get(PATH, ImmutableMap.of("limit", NO_LIMIT));
         String result = r.readEntity(String.class);
         Map<String, List<Map<String, Object>>> resultMap =
-            JsonUtil.fromJson(result,
-                              new TypeReference<Map<String, List<Map<String, Object>>>>() {});
+                JsonUtil.fromJson(result,
+                                  new TypeReference<Map<String, List<Map<String, Object>>>>() {
+                                  });
         List<Map<String, Object>> users = resultMap.get("users");
         for (Map<String, Object> user : users) {
             if ("admin".equals(user.get("user_name"))) {
@@ -172,8 +173,9 @@ public class UserApiTest extends BaseApiTest {
         String result = assertResponseStatus(200, r);
 
         Map<String, List<Map<String, Object>>> resultMap =
-            JsonUtil.fromJson(result,
-                              new TypeReference<Map<String, List<Map<String, Object>>>>() {});
+                JsonUtil.fromJson(result,
+                                  new TypeReference<Map<String, List<Map<String, Object>>>>() {
+                                  });
         return resultMap.get("users");
     }
 }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexApiTest.java
index fe474c253..292fc0aa3 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexApiTest.java
@@ -37,12 +37,12 @@ public class VertexApiTest extends BaseApiTest {
     @Test
     public void testCreate() {
         String vertex = "{" +
-                "\"label\":\"person\"," +
-                "\"properties\":{" +
-                "\"name\":\"James\"," +
-                "\"city\":\"Beijing\"," +
-                "\"age\":19}" +
-                "}";
+                        "\"label\":\"person\"," +
+                        "\"properties\":{" +
+                        "\"name\":\"James\"," +
+                        "\"city\":\"Beijing\"," +
+                        "\"age\":19}" +
+                        "}";
         Response r = client().post(PATH, vertex);
         assertResponseStatus(201, r);
     }
@@ -50,12 +50,12 @@ public class VertexApiTest extends BaseApiTest {
     @Test
     public void testGet() throws IOException {
         String vertex = "{" +
-                "\"label\":\"person\"," +
-                "\"properties\":{" +
-                "\"name\":\"James\"," +
-                "\"city\":\"Beijing\"," +
-                "\"age\":19}" +
-                "}";
+                        "\"label\":\"person\"," +
+                        "\"properties\":{" +
+                        "\"name\":\"James\"," +
+                        "\"city\":\"Beijing\"," +
+                        "\"age\":19}" +
+                        "}";
         Response r = client().post(PATH, vertex);
         String content = assertResponseStatus(201, r);
 
@@ -68,12 +68,12 @@ public class VertexApiTest extends BaseApiTest {
     @Test
     public void testList() {
         String vertex = "{" +
-                "\"label\":\"person\"," +
-                "\"properties\":{" +
-                "\"name\":\"James\"," +
-                "\"city\":\"Beijing\"," +
-                "\"age\":19}" +
-                "}";
+                        "\"label\":\"person\"," +
+                        "\"properties\":{" +
+                        "\"name\":\"James\"," +
+                        "\"city\":\"Beijing\"," +
+                        "\"age\":19}" +
+                        "}";
         Response r = client().post(PATH, vertex);
         assertResponseStatus(201, r);
 
@@ -84,12 +84,12 @@ public class VertexApiTest extends BaseApiTest {
     @Test
     public void testDelete() throws IOException {
         String vertex = "{" +
-                "\"label\":\"person\"," +
-                "\"properties\":{" +
-                "\"name\":\"James\"," +
-                "\"city\":\"Beijing\"," +
-                "\"age\":19}" +
-                "}";
+                        "\"label\":\"person\"," +
+                        "\"properties\":{" +
+                        "\"name\":\"James\"," +
+                        "\"city\":\"Beijing\"," +
+                        "\"age\":19}" +
+                        "}";
         Response r = client().post(PATH, vertex);
         String content = assertResponseStatus(201, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexLabelApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexLabelApiTest.java
index d058f6c38..71c5f99d5 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexLabelApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/VertexLabelApiTest.java
@@ -38,12 +38,12 @@ public class VertexLabelApiTest extends BaseApiTest {
     @Test
     public void testCreate() {
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"PRIMARY_KEY\"," +
-                "\"properties\": [\"name\", \"age\", \"city\"]," +
-                "\"primary_keys\":[\"name\"]," +
-                "\"nullable_keys\":[\"city\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"PRIMARY_KEY\"," +
+                             "\"properties\": [\"name\", \"age\", \"city\"]," +
+                             "\"primary_keys\":[\"name\"]," +
+                             "\"nullable_keys\":[\"city\"]" +
+                             "}";
         Response r = client().post(PATH, vertexLabel);
         assertResponseStatus(201, r);
     }
@@ -51,22 +51,22 @@ public class VertexLabelApiTest extends BaseApiTest {
     @Test
     public void testAppend() {
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"PRIMARY_KEY\"," +
-                "\"properties\": [\"name\", \"age\", \"city\"]," +
-                "\"primary_keys\":[\"name\"]," +
-                "\"nullable_keys\":[\"city\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"PRIMARY_KEY\"," +
+                             "\"properties\": [\"name\", \"age\", \"city\"]," +
+                             "\"primary_keys\":[\"name\"]," +
+                             "\"nullable_keys\":[\"city\"]" +
+                             "}";
         Response r = client().post(PATH, vertexLabel);
         assertResponseStatus(201, r);
 
         vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\":\"DEFAULT\"," +
-                "\"properties\":[\"lang\"]," +
-                "\"primary_keys\":[]," +
-                "\"nullable_keys\":[\"lang\"]" +
-                "}";
+                      "\"name\": \"person\"," +
+                      "\"id_strategy\":\"DEFAULT\"," +
+                      "\"properties\":[\"lang\"]," +
+                      "\"primary_keys\":[]," +
+                      "\"nullable_keys\":[\"lang\"]" +
+                      "}";
         Map<String, Object> params = ImmutableMap.of("action", "append");
         r = client().put(PATH, "person", vertexLabel, params);
         assertResponseStatus(200, r);
@@ -75,12 +75,12 @@ public class VertexLabelApiTest extends BaseApiTest {
     @Test
     public void testGet() {
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"PRIMARY_KEY\"," +
-                "\"properties\": [\"name\", \"age\", \"city\"]," +
-                "\"primary_keys\":[\"name\"]," +
-                "\"nullable_keys\":[\"city\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"PRIMARY_KEY\"," +
+                             "\"properties\": [\"name\", \"age\", \"city\"]," +
+                             "\"primary_keys\":[\"name\"]," +
+                             "\"nullable_keys\":[\"city\"]" +
+                             "}";
         Response r = client().post(PATH, vertexLabel);
         assertResponseStatus(201, r);
 
@@ -92,12 +92,12 @@ public class VertexLabelApiTest extends BaseApiTest {
     @Test
     public void testList() {
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"PRIMARY_KEY\"," +
-                "\"properties\": [\"name\", \"age\", \"city\"]," +
-                "\"primary_keys\":[\"name\"]," +
-                "\"nullable_keys\":[\"city\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"PRIMARY_KEY\"," +
+                             "\"properties\": [\"name\", \"age\", \"city\"]," +
+                             "\"primary_keys\":[\"name\"]," +
+                             "\"nullable_keys\":[\"city\"]" +
+                             "}";
         Response r = client().post(PATH, vertexLabel);
         assertResponseStatus(201, r);
 
@@ -108,12 +108,12 @@ public class VertexLabelApiTest extends BaseApiTest {
     @Test
     public void testDelete() {
         String vertexLabel = "{" +
-                "\"name\": \"person\"," +
-                "\"id_strategy\": \"PRIMARY_KEY\"," +
-                "\"properties\": [\"name\", \"age\", \"city\"]," +
-                "\"primary_keys\":[\"name\"]," +
-                "\"nullable_keys\":[\"city\"]" +
-                "}";
+                             "\"name\": \"person\"," +
+                             "\"id_strategy\": \"PRIMARY_KEY\"," +
+                             "\"properties\": [\"name\", \"age\", \"city\"]," +
+                             "\"primary_keys\":[\"name\"]," +
+                             "\"nullable_keys\":[\"city\"]" +
+                             "}";
         Response r = client().post(PATH, vertexLabel);
         assertResponseStatus(201, r);
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPITest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPITest.java
index 51d3b0f05..8d93e8412 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPITest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AdamicAdarAPITest.java
@@ -19,14 +19,14 @@ package org.apache.hugegraph.api.traversers;
 
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
-
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class AdamicAdarAPITest extends BaseApiTest {
 
     private static final String PATH = TRAVERSERS_API + "/adamicadar";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AllShortestPathsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AllShortestPathsApiTest.java
index e89728eb4..b17cd5f97 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AllShortestPathsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/AllShortestPathsApiTest.java
@@ -20,11 +20,11 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CountApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CountApiTest.java
index a42ecd465..cf75f51ee 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CountApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CountApiTest.java
@@ -17,12 +17,12 @@
 
 package org.apache.hugegraph.api.traversers;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
+import org.apache.hugegraph.testutil.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
-import org.apache.hugegraph.testutil.Assert;
+import jakarta.ws.rs.core.Response;
 
 public class CountApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CrosspointsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CrosspointsApiTest.java
index 028f60e67..eb59c2d79 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CrosspointsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CrosspointsApiTest.java
@@ -20,14 +20,15 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
+import org.apache.hugegraph.testutil.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
-import org.apache.hugegraph.testutil.Assert;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class CrosspointsApiTest extends BaseApiTest {
 
     public static String path = TRAVERSERS_API + "/crosspoints";
@@ -54,7 +55,7 @@ public class CrosspointsApiTest extends BaseApiTest {
         Response r = client().get(path, params);
         String content = assertResponseStatus(200, r);
         List<Map<String, Object>> crosspoints = assertJsonContains(
-                                                content, "crosspoints");
+                content, "crosspoints");
         Assert.assertEquals(2, crosspoints.size());
     }
 }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CustomizedCrosspointsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CustomizedCrosspointsApiTest.java
index a53e9195b..076200880 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CustomizedCrosspointsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/CustomizedCrosspointsApiTest.java
@@ -20,12 +20,12 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
+import jakarta.ws.rs.core.Response;
 
 public class CustomizedCrosspointsApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/EdgesApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/EdgesApiTest.java
index 4f6124f19..34915f040 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/EdgesApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/EdgesApiTest.java
@@ -20,15 +20,16 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMultimap;
 
+import jakarta.ws.rs.core.Response;
+
 public class EdgesApiTest extends BaseApiTest {
 
     static final String EDGE_PATH = TRAVERSERS_API + "/edges";
@@ -50,8 +51,8 @@ public class EdgesApiTest extends BaseApiTest {
         final String edgeGetPath = "graphs/hugegraph/graph/edges";
         String vadasId = name2Ids.get("vadas");
         Map<String, Object> params = ImmutableMap.of(
-                                     "vertex_id", id2Json(vadasId),
-                                     "direction", "IN");
+                "vertex_id", id2Json(vadasId),
+                "direction", "IN");
         Response r = client().get(edgeGetPath, params);
         String content = assertResponseStatus(200, r);
         List<Map<?, ?>> edges = assertJsonContains(content, "edges");
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/FusiformSimilarityApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/FusiformSimilarityApiTest.java
index 602bc74b8..2ebee13ab 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/FusiformSimilarityApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/FusiformSimilarityApiTest.java
@@ -20,12 +20,12 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
+import jakarta.ws.rs.core.Response;
 
 public class FusiformSimilarityApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/MultiNodeShortestPathApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/MultiNodeShortestPathApiTest.java
index aa1703f6f..f77debbd7 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/MultiNodeShortestPathApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/MultiNodeShortestPathApiTest.java
@@ -20,12 +20,12 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
+import jakarta.ws.rs.core.Response;
 
 public class MultiNodeShortestPathApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankApiTest.java
index f6d6f826d..3b79bb396 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/NeighborRankApiTest.java
@@ -20,12 +20,12 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
+import jakarta.ws.rs.core.Response;
 
 public class NeighborRankApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PathsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PathsApiTest.java
index b332effdb..39cf23880 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PathsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PathsApiTest.java
@@ -20,15 +20,15 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
-
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class PathsApiTest extends BaseApiTest {
 
     static final String PATH = TRAVERSERS_API + "/paths";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankApiTest.java
index 71e1a7525..8ab44ad18 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/PersonalRankApiTest.java
@@ -19,11 +19,11 @@ package org.apache.hugegraph.api.traversers;
 
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
+import jakarta.ws.rs.core.Response;
 
 public class PersonalRankApiTest extends BaseApiTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPITest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPITest.java
index bdfd0462c..d603a0775 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPITest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ResourceAllocationAPITest.java
@@ -19,14 +19,14 @@ package org.apache.hugegraph.api.traversers;
 
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
-
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class ResourceAllocationAPITest extends BaseApiTest {
 
     private static final String PATH = TRAVERSERS_API + "/resourceallocation";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/RingsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/RingsApiTest.java
index 9cf02a309..154b1b019 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/RingsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/RingsApiTest.java
@@ -20,14 +20,15 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class RingsApiTest extends BaseApiTest {
 
     static final String PATH = TRAVERSERS_API + "/rings";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ShortestPathApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ShortestPathApiTest.java
index 3bd70255b..9a613d1cb 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ShortestPathApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/ShortestPathApiTest.java
@@ -20,15 +20,16 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class ShortestPathApiTest extends BaseApiTest {
 
     static final String PATH = TRAVERSERS_API + "/shortestpath";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TemplatePathsApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TemplatePathsApiTest.java
index a33b15478..887c7f9b6 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TemplatePathsApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TemplatePathsApiTest.java
@@ -20,14 +20,15 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableList;
 
+import jakarta.ws.rs.core.Response;
+
 public class TemplatePathsApiTest extends BaseApiTest {
 
     static final String PATH = TRAVERSERS_API + "/templatepaths";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TraversersApiTestSuite.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TraversersApiTestSuite.java
index 3c6c99278..8146375c1 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TraversersApiTestSuite.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/TraversersApiTestSuite.java
@@ -22,28 +22,29 @@ import org.junit.runners.Suite;
 
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
-    AllShortestPathsApiTest.class,
-    CountApiTest.class,
-    CrosspointsApiTest.class,
-    CustomizedCrosspointsApiTest.class,
-    EdgesApiTest.class,
-    FusiformSimilarityApiTest.class,
-    JaccardSimilarityApiTest.class,
-    KneighborApiTest.class,
-    KoutApiTest.class,
-    MultiNodeShortestPathApiTest.class,
-    NeighborRankApiTest.class,
-    PathsApiTest.class,
-    PersonalRankApiTest.class,
-    RaysApiTest.class,
-    RingsApiTest.class,
-    SameNeighborsApiTest.class,
-    ShortestPathApiTest.class,
-    SingleSourceShortestPathApiTest.class,
-    TemplatePathsApiTest.class,
-    WeightedShortestPathApiTest.class,
-    AdamicAdarAPITest.class,
-    ResourceAllocationAPITest.class
+        AllShortestPathsApiTest.class,
+        CountApiTest.class,
+        CrosspointsApiTest.class,
+        CustomizedCrosspointsApiTest.class,
+        EdgesApiTest.class,
+        FusiformSimilarityApiTest.class,
+        JaccardSimilarityApiTest.class,
+        KneighborApiTest.class,
+        KoutApiTest.class,
+        MultiNodeShortestPathApiTest.class,
+        NeighborRankApiTest.class,
+        PathsApiTest.class,
+        PersonalRankApiTest.class,
+        RaysApiTest.class,
+        RingsApiTest.class,
+        SameNeighborsApiTest.class,
+        ShortestPathApiTest.class,
+        SingleSourceShortestPathApiTest.class,
+        TemplatePathsApiTest.class,
+        WeightedShortestPathApiTest.class,
+        AdamicAdarAPITest.class,
+        ResourceAllocationAPITest.class
 })
 public class TraversersApiTestSuite {
+
 }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/WeightedShortestPathApiTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/WeightedShortestPathApiTest.java
index 5ed76748c..7331f2320 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/WeightedShortestPathApiTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/api/traversers/WeightedShortestPathApiTest.java
@@ -20,15 +20,16 @@ package org.apache.hugegraph.api.traversers;
 import java.util.List;
 import java.util.Map;
 
-import jakarta.ws.rs.core.Response;
+import org.apache.hugegraph.api.BaseApiTest;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import org.apache.hugegraph.api.BaseApiTest;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
+import jakarta.ws.rs.core.Response;
+
 public class WeightedShortestPathApiTest extends BaseApiTest {
 
     static final String PATH = TRAVERSERS_API + "/weightedshortestpath";
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/AuthTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/AuthTest.java
index 457e0ab06..1db7af924 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/AuthTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/AuthTest.java
@@ -25,9 +25,6 @@ import java.util.Map;
 import javax.security.sasl.AuthenticationException;
 
 import org.apache.commons.collections.CollectionUtils;
-import org.junit.After;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.auth.AuthManager;
@@ -49,6 +46,9 @@ import org.apache.hugegraph.testutil.Assert;
 import org.apache.hugegraph.testutil.Whitebox;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.StringEncoding;
+import org.junit.After;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
@@ -352,7 +352,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertEquals("group2", groups.get(2).name());
 
         groups = authManager.listGroups(ImmutableList.of(
-                                        id1, id2, IdGenerator.of("fake")));
+                id1, id2, IdGenerator.of("fake")));
         Assert.assertEquals(2, groups.size());
     }
 
@@ -497,7 +497,7 @@ public class AuthTest extends BaseCoreTest {
                         "{\"type\":\"EDGE\",\"label\":\"transfer\"," +
                         "\"properties\":null}]";
         Assert.assertEquals(expect, JsonUtil.toJson(target.asMap()
-                                                    .get("target_resources")));
+                                                          .get("target_resources")));
     }
 
     @Test
@@ -509,7 +509,7 @@ public class AuthTest extends BaseCoreTest {
         Id id2 = authManager.createTarget(makeTarget("target2", "url2"));
 
         List<HugeTarget> targets = authManager.listTargets(ImmutableList.of(
-                                                           id1, id2));
+                id1, id2));
         Assert.assertEquals(2, targets.size());
         Assert.assertEquals("target1", targets.get(0).name());
         Assert.assertEquals("target2", targets.get(1).name());
@@ -521,7 +521,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertEquals("target2", targets.get(2).name());
 
         targets = authManager.listTargets(ImmutableList.of(
-                                          id1, id2, IdGenerator.of("fake")));
+                id1, id2, IdGenerator.of("fake")));
         Assert.assertEquals(2, targets.size());
     }
 
@@ -710,7 +710,7 @@ public class AuthTest extends BaseCoreTest {
         Id id2 = authManager.createBelong(makeBelong(user, group2));
 
         List<HugeBelong> belongs = authManager.listBelong(ImmutableList.of(
-                                                          id1, id2));
+                id1, id2));
         Assert.assertEquals(2, belongs.size());
         Assert.assertEquals(user, belongs.get(0).source());
         Assert.assertEquals(user, belongs.get(1).source());
@@ -721,7 +721,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertEquals(3, belongs.size());
 
         belongs = authManager.listBelong(ImmutableList.of(
-                                         id1, id2, IdGenerator.of("fake")));
+                id1, id2, IdGenerator.of("fake")));
         Assert.assertEquals(2, belongs.size());
 
         belongs = authManager.listBelongByUser(user, -1);
@@ -793,7 +793,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertThrows(IllegalArgumentException.class, () -> {
             Id target = authManager.createTarget(makeTarget("graph1", ""));
             Id access = authManager.createAccess(makeAccess(group1, target,
-                                                 HugePermission.READ));
+                                                            HugePermission.READ));
             authManager.getBelong(access);
         });
     }
@@ -865,7 +865,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertThrows(IllegalArgumentException.class, () -> {
             Id target = authManager.createTarget(makeTarget("graph1", ""));
             Id access = authManager.createAccess(makeAccess(group1, target,
-                                                 HugePermission.READ));
+                                                            HugePermission.READ));
             authManager.deleteBelong(access);
         });
     }
@@ -1016,7 +1016,7 @@ public class AuthTest extends BaseCoreTest {
                                                      HugePermission.READ));
 
         List<HugeAccess> access = authManager.listAccess(ImmutableList.of(
-                                                         id1, id2));
+                id1, id2));
         Assert.assertEquals(2, access.size());
         Assert.assertEquals(group, access.get(0).source());
         Assert.assertEquals(group, access.get(1).source());
@@ -1027,7 +1027,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertEquals(3, access.size());
 
         access = authManager.listAccess(ImmutableList.of(
-                                        id1, id2, IdGenerator.of("fake")));
+                id1, id2, IdGenerator.of("fake")));
         Assert.assertEquals(2, access.size());
 
         access = authManager.listAccessByGroup(group, -1);
@@ -1215,16 +1215,16 @@ public class AuthTest extends BaseCoreTest {
         Id graph2 = authManager.createTarget(makeTarget("hugegraph1", "url2"));
 
         List<HugeResource> rv = HugeResource.parseResources(
-            "[{\"type\": \"VERTEX\", \"label\": \"person\", " +
-            "\"properties\":{\"city\": \"Beijing\", \"age\": \"P.gte(20)\"}}," +
-            " {\"type\": \"VERTEX_LABEL\", \"label\": \"*\"}," +
-            " {\"type\": \"PROPERTY_KEY\", \"label\": \"*\"}]");
+                "[{\"type\": \"VERTEX\", \"label\": \"person\", " +
+                "\"properties\":{\"city\": \"Beijing\", \"age\": \"P.gte(20)\"}}," +
+                " {\"type\": \"VERTEX_LABEL\", \"label\": \"*\"}," +
+                " {\"type\": \"PROPERTY_KEY\", \"label\": \"*\"}]");
         List<HugeResource> re = HugeResource.parseResources(
-            "[{\"type\": \"EDGE\", \"label\": \"write\"}, " +
-            " {\"type\": \"PROPERTY_KEY\"}, {\"type\": \"VERTEX_LABEL\"}, " +
-            " {\"type\": \"EDGE_LABEL\"}, {\"type\": \"INDEX_LABEL\"}]");
+                "[{\"type\": \"EDGE\", \"label\": \"write\"}, " +
+                " {\"type\": \"PROPERTY_KEY\"}, {\"type\": \"VERTEX_LABEL\"}, " +
+                " {\"type\": \"EDGE_LABEL\"}, {\"type\": \"INDEX_LABEL\"}]");
         List<HugeResource> rg = HugeResource.parseResources(
-            "[{\"type\": \"GREMLIN\"}]");
+                "[{\"type\": \"GREMLIN\"}]");
         Id graph1v = authManager.createTarget(makeTarget("hugegraph-v", "hugegraph",
                                                          "url1", rv));
         Id graph1e = authManager.createTarget(makeTarget("hugegraph-e", "hugegraph",
@@ -1251,27 +1251,29 @@ public class AuthTest extends BaseCoreTest {
         authManager.createAccess(makeAccess(group1, graph1e,
                                             HugePermission.READ));
         Id access1g = authManager.createAccess(makeAccess(group1, graph1gremlin,
-                                               HugePermission.EXECUTE));
+                                                          HugePermission.EXECUTE));
 
         RolePermission role;
         role = authManager.rolePermission(authManager.getUser(user0));
         String expected = "{\"roles\":" +
-                "{\"hugegraph\":{\"READ\":[" +
-                "{\"type\":\"EDGE\",\"label\":\"write\",\"properties\":null}," +
-                "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"EDGE_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"INDEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
-                "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
-                "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}],\"WRITE\":" +
-                "[{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
-                "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
-                "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}],\"EXECUTE\":" +
-                "[{\"type\":\"GREMLIN\",\"label\":\"*\",\"properties\":null}]}," +
-                "\"hugegraph1\":{\"READ\":[]}}}";
+                          "{\"hugegraph\":{\"READ\":[" +
+                          "{\"type\":\"EDGE\",\"label\":\"write\",\"properties\":null}," +
+                          "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"EDGE_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"INDEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
+                          "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
+                          "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]," +
+                          "\"WRITE\":" +
+                          "[{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
+                          "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
+                          "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                          "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]," +
+                          "\"EXECUTE\":" +
+                          "[{\"type\":\"GREMLIN\",\"label\":\"*\",\"properties\":null}]}," +
+                          "\"hugegraph1\":{\"READ\":[]}}}";
         Assert.assertEquals(expected, role.toJson());
 
         role = authManager.rolePermission(authManager.getBelong(belong1));
@@ -1282,15 +1284,15 @@ public class AuthTest extends BaseCoreTest {
 
         role = authManager.rolePermission(authManager.getAccess(access1v));
         expected = "{\"roles\":" +
-                "{\"hugegraph\":{\"READ\":[{\"type\":\"VERTEX\",\"label\":\"person\"," +
-                "\"properties\":{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
-                "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]}}}";
+                   "{\"hugegraph\":{\"READ\":[{\"type\":\"VERTEX\",\"label\":\"person\"," +
+                   "\"properties\":{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
+                   "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                   "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]}}}";
         Assert.assertEquals(expected, role.toJson());
 
         role = authManager.rolePermission(authManager.getAccess(access1g));
         expected = "{\"roles\":{\"hugegraph\":{\"EXECUTE\":[" +
-                "{\"type\":\"GREMLIN\",\"label\":\"*\",\"properties\":null}]}}}";
+                   "{\"type\":\"GREMLIN\",\"label\":\"*\",\"properties\":null}]}}}";
         Assert.assertEquals(expected, role.toJson());
 
         role = authManager.rolePermission(authManager.getUser(user1));
@@ -1303,11 +1305,11 @@ public class AuthTest extends BaseCoreTest {
 
         role = authManager.rolePermission(authManager.getTarget(graph1v));
         expected = "{\"roles\":" +
-                "{\"hugegraph\":" +
-                "{\"READ\":[{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
-                "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
-                "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
-                "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]}}}";
+                   "{\"hugegraph\":" +
+                   "{\"READ\":[{\"type\":\"VERTEX\",\"label\":\"person\",\"properties\":" +
+                   "{\"city\":\"Beijing\",\"age\":\"P.gte(20)\"}}," +
+                   "{\"type\":\"VERTEX_LABEL\",\"label\":\"*\",\"properties\":null}," +
+                   "{\"type\":\"PROPERTY_KEY\",\"label\":\"*\",\"properties\":null}]}}}";
         Assert.assertEquals(expected, role.toJson());
     }
 
@@ -1483,7 +1485,7 @@ public class AuthTest extends BaseCoreTest {
         Assert.assertNotNull(project);
         Assert.assertFalse(project.graphs().isEmpty());
         projectId = authManager.projectRemoveGraphs(
-                                project.id(), ImmutableSet.of("graph_test"));
+                project.id(), ImmutableSet.of("graph_test"));
         project = authManager.getProject(projectId);
         Assert.assertNotNull(project);
         Assert.assertTrue(project.graphs().isEmpty());
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
index 686d7894b..17e01a4fa 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/CoreTestSuite.java
@@ -24,19 +24,20 @@ import org.junit.runners.Suite;
 
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
-    PropertyKeyCoreTest.class,
-    VertexLabelCoreTest.class,
-    EdgeLabelCoreTest.class,
-    IndexLabelCoreTest.class,
-    VertexCoreTest.class,
-    EdgeCoreTest.class,
-    VertexPropertyCoreTest.class,
-    EdgePropertyCoreTest.class,
-    RestoreCoreTest.class,
-    TaskCoreTest.class,
-    AuthTest.class,
-    MultiGraphsTest.class,
-    RamTableTest.class
+        PropertyKeyCoreTest.class,
+        VertexLabelCoreTest.class,
+        EdgeLabelCoreTest.class,
+        IndexLabelCoreTest.class,
+        VertexCoreTest.class,
+        EdgeCoreTest.class,
+        VertexPropertyCoreTest.class,
+        EdgePropertyCoreTest.class,
+        RestoreCoreTest.class,
+        TaskCoreTest.class,
+        AuthTest.class,
+        MultiGraphsTest.class,
+        RamTableTest.class
 })
 public class CoreTestSuite {
+
 }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeCoreTest.java
index bccf211b9..80d04e984 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeCoreTest.java
@@ -219,9 +219,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -254,9 +254,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -297,8 +297,8 @@ public class EdgeCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
 
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
-                                      "name", "James Gosling", "age", 62,
-                                      "lived", "Canadian");
+                                       "name", "James Gosling", "age", 62,
+                                       "lived", "Canadian");
 
         Vertex book = graph.addVertex(T.label, "book", "name", "Test-Book-1");
 
@@ -539,9 +539,9 @@ public class EdgeCoreTest extends BaseCoreTest {
             graph.tx().commit();
 
             List<Edge> edges = graph.traversal().V(james.id())
-                                                .outE("write")
-                                                .has("time", "2017-5-27\u0000")
-                                                .toList();
+                                    .outE("write")
+                                    .has("time", "2017-5-27\u0000")
+                                    .toList();
             Assert.assertEquals(1, edges.size());
             Assert.assertEquals("2017-5-27\u0000", edges.get(0).value("time"));
         }
@@ -1138,7 +1138,7 @@ public class EdgeCoreTest extends BaseCoreTest {
                                   "date", "2019-12-23 15:01:00");
         Edge edge10 = baby.addEdge("read", java5,
                                    "place", "library of school",
-                                  "date", "2019-12-23 16:01:00");
+                                   "date", "2019-12-23 16:01:00");
         graph().tx().commit();
         // Due to overridden edges are expired, query will lead to async delete
         edges = graph().traversal().E().has("date", "2019-12-23 14:00:00");
@@ -1274,12 +1274,12 @@ public class EdgeCoreTest extends BaseCoreTest {
         @SuppressWarnings("unused")
         Edge edge10 = baby.addEdge("read", java4,
                                    "place", "library of school",
-                                  "date", "2019-12-23 15:01:00");
+                                   "date", "2019-12-23 15:01:00");
         Edge edge11 = baby.addEdge("read", java5,
                                    "place", "library of school",
-                                  "date", "2019-12-23 16:01:00");
+                                   "date", "2019-12-23 16:01:00");
         Edge edge12 = baby.addEdge("read", java6, "place", "library",
-                                  "date", "2019-12-23 14:01:00");
+                                   "date", "2019-12-23 14:01:00");
         graph().tx().commit();
 
         // Due to overridden edges are expired, query will lead to async delete
@@ -1416,11 +1416,11 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex java2 = graph().addVertex(T.label, "book",
                                          "name", "Java2 in action");
         Edge edge1 = baby.addEdge("read", java1, "place", "library of school",
-                                 "date", "2019-12-23 12:00:00");
+                                  "date", "2019-12-23 12:00:00");
         graph().tx().commit();
         // Add edges in tx
         Edge edge2 = baby.addEdge("read", java2, "place", "library of school",
-                                 "date", "2019-12-23 12:00:00");
+                                  "date", "2019-12-23 12:00:00");
 
         Iterator<Edge> edges = graph().edges(edge1);
         Assert.assertTrue(edges.hasNext());
@@ -1777,9 +1777,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         init18Edges();
 
         List<Edge> edges = graph.traversal().V()
-                           .hasLabel("person").has("name", "Louise")
-                           .outE("look").order().by("time")
-                           .toList();
+                                .hasLabel("person").has("name", "Louise")
+                                .outE("look").order().by("time")
+                                .toList();
         Assert.assertEquals(4, edges.size());
         Assert.assertEquals("2017-5-1", edges.get(0).value("time"));
         Assert.assertEquals("2017-5-1", edges.get(1).value("time"));
@@ -1998,23 +1998,23 @@ public class EdgeCoreTest extends BaseCoreTest {
         Assert.assertEquals(1, edges.size());
 
         edges = graph.traversal().E()
-                                 .range(1, -1)
-                                 .range(6, 8)
-                                 .toList();
+                     .range(1, -1)
+                     .range(6, 8)
+                     .toList();
         // [7, 9)
         Assert.assertEquals(2, edges.size());
 
         edges = graph.traversal().E()
-                                 .range(1, 6)
-                                 .range(6, 8)
-                                 .toList();
+                     .range(1, 6)
+                     .range(6, 8)
+                     .toList();
         // [7, 6) will be converted to NoneStep by EarlyLimitStrategy
         Assert.assertEquals(0, edges.size());
 
         edges = graph.traversal().E()
-                                 .range(1, 6)
-                                 .range(7, 8)
-                                 .toList();
+                     .range(1, 6)
+                     .range(7, 8)
+                     .toList();
         // [8, 6) will be converted to NoneStep by EarlyLimitStrategy
         Assert.assertEquals(0, edges.size());
     }
@@ -2962,7 +2962,7 @@ public class EdgeCoreTest extends BaseCoreTest {
         HugeVertex james = (HugeVertex) vertex("author", "id", 1);
 
         List<Vertex> vertices = ImmutableList.copyOf(
-                                james.getVertices(Directions.BOTH));
+                james.getVertices(Directions.BOTH));
         Assert.assertEquals(6, vertices.size());
 
         vertices = ImmutableList.copyOf(james.getVertices(Directions.OUT));
@@ -3014,7 +3014,7 @@ public class EdgeCoreTest extends BaseCoreTest {
         // Query edges of a vertex
         Vertex james = vertex("author", "id", 1);
         List<Edge> edges = ImmutableList.copyOf(
-                           graph.adjacentEdges((Id) james.id()));
+                graph.adjacentEdges((Id) james.id()));
         Assert.assertEquals(6, edges.size());
 
         List<Edge> edges2 = ImmutableList.copyOf(james.edges(Direction.BOTH));
@@ -3063,9 +3063,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author2", T.id, 13579,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author2", T.id, 24680,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author2", T.id, 24680,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language2", "name", "java",
                                       T.id, UUID.randomUUID());
@@ -3131,7 +3131,7 @@ public class EdgeCoreTest extends BaseCoreTest {
         Assert.assertEquals(2, vertices.size());
 
         vertices = ImmutableList.copyOf(
-                   jeff.vertices(Direction.BOTH, "friend"));
+                jeff.vertices(Direction.BOTH, "friend"));
         Assert.assertEquals(2, vertices.size());
 
         // OUT
@@ -3193,7 +3193,7 @@ public class EdgeCoreTest extends BaseCoreTest {
 
     @Test
     public void testQueryAdjacentVerticesOfEdgesWithoutVertex()
-                throws InterruptedException, ExecutionException {
+            throws InterruptedException, ExecutionException {
         HugeGraph graph = graph();
 
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
@@ -3261,7 +3261,7 @@ public class EdgeCoreTest extends BaseCoreTest {
             Assert.assertThrows(HugeException.class, () -> {
                 // read from cache
                 graph.traversal().V(james.id()).outE().has("score", 3)
-                                 .otherV().values().toList();
+                     .otherV().values().toList();
             }, e -> {
                 Assert.assertContains("Vertex 'java' does not exist",
                                       e.getMessage());
@@ -3286,7 +3286,7 @@ public class EdgeCoreTest extends BaseCoreTest {
 
             Assert.assertThrows(HugeException.class, () -> {
                 graph.traversal().V(james.id()).outE().otherV()
-                                 .values().toList();
+                     .values().toList();
             }, e -> {
                 Assert.assertContains("Vertex 'java' does not exist",
                                       e.getMessage());
@@ -3326,7 +3326,7 @@ public class EdgeCoreTest extends BaseCoreTest {
 
     @Test
     public void testQueryAdjacentVerticesOfEdgesWithInvalidVertexLabel()
-                throws InterruptedException, ExecutionException {
+            throws InterruptedException, ExecutionException {
         HugeGraph graph = graph();
         SchemaManager schema = graph.schema();
 
@@ -3400,7 +3400,7 @@ public class EdgeCoreTest extends BaseCoreTest {
 
     @Test
     public void testQueryAdjacentVerticesOfEdgesWithoutVertexAndNoLazyLoad()
-                throws InterruptedException, ExecutionException {
+            throws InterruptedException, ExecutionException {
         HugeGraph graph = graph();
 
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
@@ -3421,7 +3421,7 @@ public class EdgeCoreTest extends BaseCoreTest {
             Assert.assertEquals(0, graph.traversal().V(java).toList().size());
 
             List<Vertex> vertices = graph.traversal().V(james.id())
-                                                     .out().toList();
+                                         .out().toList();
             Assert.assertEquals(1, vertices.size());
             HugeVertex adjacent = (HugeVertex) vertices.get(0);
             Assert.assertTrue("label: " + adjacent.schemaLabel(),
@@ -4604,23 +4604,23 @@ public class EdgeCoreTest extends BaseCoreTest {
 
         long size;
         size = graph.traversal().V().outE("created", "authored", "look")
-                                    .hasLabel("authored", "created")
-                                    .count().next();
+                    .hasLabel("authored", "created")
+                    .count().next();
         Assert.assertEquals(5L, size);
 
         size = graph.traversal().V().outE("created", "authored", "look")
-                                    .hasLabel("authored", "friend")
-                                    .count().next();
+                    .hasLabel("authored", "friend")
+                    .count().next();
         Assert.assertEquals(3L, size);
 
         size = graph.traversal().V().outE("created")
-                                    .hasLabel("authored", "created")
-                                    .count().next();
+                    .hasLabel("authored", "created")
+                    .count().next();
         Assert.assertEquals(2L, size);
 
         size = graph.traversal().V().inE("created", "authored", "look")
-                                    .has("score", 3)
-                                    .count().next();
+                    .has("score", 3)
+                    .count().next();
         Assert.assertEquals(3L, size);
     }
 
@@ -4812,11 +4812,11 @@ public class EdgeCoreTest extends BaseCoreTest {
         schema.indexLabel("buyByDate").onE("buy").by("date").range().create();
 
         Vertex louise = graph.addVertex(T.label, "person", "name", "Louise",
-                "city", "Beijing", "age", 21);
+                                        "city", "Beijing", "age", 21);
         Vertex jeff = graph.addVertex(T.label, "person", "name", "Jeff",
-                "city", "Beijing", "age", 22);
+                                      "city", "Beijing", "age", 22);
         Vertex sean = graph.addVertex(T.label, "person", "name", "Sean",
-                "city", "Beijing", "age", 23);
+                                      "city", "Beijing", "age", 23);
 
         Vertex java1 = graph.addVertex(T.label, "book", "name", "java-1");
         Vertex java2 = graph.addVertex(T.label, "book", "name", "java-2");
@@ -4873,9 +4873,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex java3 = graph.addVertex(T.label, "book", "name", "java-3");
 
         String[] dates = new String[]{
-            "2012-01-01 00:00:00.000",
-            "2013-01-01 00:00:00.000",
-            "2014-01-01 00:00:00.000"
+                "2012-01-01 00:00:00.000",
+                "2013-01-01 00:00:00.000",
+                "2014-01-01 00:00:00.000"
         };
 
         louise.addEdge("buy", java1, "place", "haidian", "date", dates[0]);
@@ -4925,9 +4925,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex java3 = graph.addVertex(T.label, "book", "name", "java-3");
 
         String[] dates = new String[]{
-            "2012-01-01 00:00:00.000",
-            "2013-01-01 00:00:00.000",
-            "2014-01-01 00:00:00.000"
+                "2012-01-01 00:00:00.000",
+                "2013-01-01 00:00:00.000",
+                "2014-01-01 00:00:00.000"
         };
 
         louise.addEdge("buy", java1, "place", "haidian", "date", dates[0]);
@@ -4978,9 +4978,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex java3 = graph.addVertex(T.label, "book", "name", "java-3");
 
         String[] dates = new String[]{
-            "2012-01-01",
-            "2013-01-01 00:00:00",
-            "2014-01-01 00:00:00.000"
+                "2012-01-01",
+                "2013-01-01 00:00:00",
+                "2014-01-01 00:00:00.000"
         };
 
         louise.addEdge("buy", java1, "place", "haidian", "date", dates[0]);
@@ -5028,9 +5028,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex java3 = graph.addVertex(T.label, "book", "name", "java-3");
 
         String[] dates = new String[]{
-            "2012-01-01 00:00:00.000",
-            "2013-01-01 00:00:00.000",
-            "2014-01-01 00:00:00.000"
+                "2012-01-01 00:00:00.000",
+                "2013-01-01 00:00:00.000",
+                "2014-01-01 00:00:00.000"
         };
 
         louise.addEdge("buy", java1, "place", "haidian", "date", dates[0]);
@@ -5079,14 +5079,14 @@ public class EdgeCoreTest extends BaseCoreTest {
                        "contribution", "1992 2 2", "score", 4);
 
         edges = graph.traversal().E().hasLabel("authored")
-                                 .has("contribution", Text.contains("2"))
-                                 .toList();
+                     .has("contribution", Text.contains("2"))
+                     .toList();
         Assert.assertEquals(2, edges.size());
 
         edges = graph.traversal().E().hasLabel("authored")
-                                 .has("score", P.gt(3))
-                                 .has("contribution", Text.contains("3"))
-                                 .toList();
+                     .has("score", P.gt(3))
+                     .has("contribution", Text.contains("3"))
+                     .toList();
         Assert.assertEquals(1, edges.size());
         assertContains(edges, "authored", james, book1,
                        "contribution", "1991 3 1", "score", 5);
@@ -5125,22 +5125,22 @@ public class EdgeCoreTest extends BaseCoreTest {
 
         // Won't query by search index, just filter by property after outE()
         edges = graph.traversal().V(james).outE("authored")
-                                 .has("contribution", "1992 2 2")
-                                 .toList();
+                     .has("contribution", "1992 2 2")
+                     .toList();
         Assert.assertEquals(1, edges.size());
 
         // Won't query by search index, just filter by property after outE()
         edges = graph.traversal().V(james).outE("authored")
-                                 .has("contribution", "1992 2 2")
-                                 .has("score", P.gte(4))
-                                 .toList();
+                     .has("contribution", "1992 2 2")
+                     .has("score", P.gte(4))
+                     .toList();
         Assert.assertEquals(1, edges.size());
 
         // Won't query by search index, just filter by property after outE()
         edges = graph.traversal().V(james).outE("authored")
-                                 .has("contribution", "1992 2 2")
-                                 .has("score", P.gt(4))
-                                 .toList();
+                     .has("contribution", "1992 2 2")
+                     .has("score", P.gt(4))
+                     .toList();
         Assert.assertEquals(0, edges.size());
 
         // Query by search index
@@ -5151,8 +5151,8 @@ public class EdgeCoreTest extends BaseCoreTest {
 
         // Won't query by search index, just filter by property after outE()
         edges = graph.traversal().V(james).outE("authored")
-                                 .has("contribution", "1992")
-                                 .toList();
+                     .has("contribution", "1992")
+                     .toList();
         Assert.assertEquals(0, edges.size()); // be careful!
     }
 
@@ -5313,53 +5313,53 @@ public class EdgeCoreTest extends BaseCoreTest {
         Assert.assertEquals(4L, g.E().hasLabel("friend").count().next());
         Assert.assertEquals(1L, g.E().hasLabel("follow").count().next());
         Assert.assertEquals(11L, g.E().hasLabel("look", "friend")
-                                      .count().next());
+                                  .count().next());
 
         Assert.assertEquals(5L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27").count().next());
+                                 .has("time", "2017-5-27").count().next());
         Assert.assertEquals(2L, g.E().hasLabel("look")
-                                     .has("score", 3).count().next());
+                                 .has("score", 3).count().next());
         Assert.assertEquals(3L, g.E().hasLabel("look")
-                                     .has("score", P.gte(3)).count().next());
+                                 .has("score", P.gte(3)).count().next());
         Assert.assertEquals(1L, g.E().hasLabel("look")
-                                     .has("score", P.lt(3)).count().next());
+                                 .has("score", P.lt(3)).count().next());
 
         Assert.assertEquals(1L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", 3)
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", 3)
+                                 .count().next());
         Assert.assertEquals(2L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.gte(3))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.gte(3))
+                                 .count().next());
         Assert.assertEquals(2L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.gt(0))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.gt(0))
+                                 .count().next());
         Assert.assertEquals(3L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.gte(0))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.gte(0))
+                                 .count().next());
         Assert.assertEquals(0L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.lt(0))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.lt(0))
+                                 .count().next());
         Assert.assertEquals(1L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.lte(0))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.lte(0))
+                                 .count().next());
         Assert.assertEquals(2L, g.E().hasLabel("look")
-                                     .has("time", "2017-5-27")
-                                     .has("score", P.lte(3))
-                                     .count().next());
+                                 .has("time", "2017-5-27")
+                                 .has("score", P.lte(3))
+                                 .count().next());
 
         Assert.assertEquals(18L, g.E().count().min().next());
         Assert.assertEquals(7L, g.E().hasLabel("look").count().max().next());
 
         Assert.assertEquals(4L, g.E().hasLabel("look")
-                                     .values("score").count().next());
+                                 .values("score").count().next());
         Assert.assertEquals(11L, g.E().hasLabel("look")
-                                      .values().count().next());
+                                  .values().count().next());
     }
 
     @Test
@@ -5435,7 +5435,7 @@ public class EdgeCoreTest extends BaseCoreTest {
         edges = graph.traversal().E().toList();
         Assert.assertEquals(3, edges.size());
         Assert.assertFalse(Utils.contains(edges,
-                           new FakeObjects.FakeEdge("authored", james, java1)));
+                                          new FakeObjects.FakeEdge("authored", james, java1)));
     }
 
     @Test
@@ -5499,9 +5499,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -5534,9 +5534,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -5584,9 +5584,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -6506,14 +6506,14 @@ public class EdgeCoreTest extends BaseCoreTest {
                   .onE("attack").by("port").secondary().ifNotExist().create();
         }, e -> {
             Assert.assertTrue(e.getMessage(), e.getMessage().contains(
-                              "The aggregate type SET is not indexable"));
+                    "The aggregate type SET is not indexable"));
         });
         Assert.assertThrows(IllegalArgumentException.class, () -> {
             schema.indexLabel("attackByType")
                   .onE("attack").by("type").secondary().ifNotExist().create();
         }, e -> {
             Assert.assertTrue(e.getMessage(), e.getMessage().contains(
-                              "The aggregate type LIST is not indexable"));
+                    "The aggregate type LIST is not indexable"));
         });
 
         Vertex ip1 = graph.addVertex(T.label, "ip", T.id, "10.0.0.1");
@@ -7020,7 +7020,7 @@ public class EdgeCoreTest extends BaseCoreTest {
                                    "arrested", false);
 
         List<Edge> el = graph.traversal().E().has("tool", "shovel")
-                        .toList();
+                             .toList();
         Assert.assertEquals(1, el.size());
         Assert.assertEquals(1, (int) el.get(0).value("id"));
         el = graph.traversal().E().has("tool", "knife").toList();
@@ -7051,7 +7051,7 @@ public class EdgeCoreTest extends BaseCoreTest {
                                    "arrested", false);
 
         List<Edge> el = graph.traversal().E().has("timestamp", current)
-                        .toList();
+                             .toList();
         Assert.assertEquals(1, el.size());
         Assert.assertEquals(1, (int) el.get(0).value("id"));
         el = graph.traversal().E().has("timestamp", 666L).toList();
@@ -7081,7 +7081,7 @@ public class EdgeCoreTest extends BaseCoreTest {
                        "tool", "shovel", "arrested", false);
 
         List<Edge> el = graph.traversal().E().has("place", "park")
-                        .toList();
+                             .toList();
         Assert.assertEquals(1, el.size());
         Assert.assertEquals(1, (int) el.get(0).value("id"));
         el = graph.traversal().E().has("place", "park")
@@ -7331,23 +7331,23 @@ public class EdgeCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
 
         Vertex huge = graph.addVertex(
-                      T.label, "soft",
-                      "name", "hugegraph",
-                      "country", "china",
-                      "category", ImmutableList.of("graphdb", "db"),
-                      "tags", ImmutableList.of("graphdb", "gremlin"));
+                T.label, "soft",
+                "name", "hugegraph",
+                "country", "china",
+                "category", ImmutableList.of("graphdb", "db"),
+                "tags", ImmutableList.of("graphdb", "gremlin"));
 
         Vertex neo4j = graph.addVertex(
-                       T.label, "soft", "name", "neo4j",
-                       "country", "usa",
-                       "category", ImmutableList.of("graphdb", "db"),
-                       "tags", ImmutableList.of("graphdb", "cypher"));
+                T.label, "soft", "name", "neo4j",
+                "country", "usa",
+                "category", ImmutableList.of("graphdb", "db"),
+                "tags", ImmutableList.of("graphdb", "cypher"));
 
         Vertex janus = graph.addVertex(
-                       T.label, "soft", "name", "janusgraph",
-                       "country", "usa",
-                       "category", ImmutableList.of("graphdb", "db"),
-                       "tags", ImmutableList.of("graphdb", "gremlin"));
+                T.label, "soft", "name", "janusgraph",
+                "country", "usa",
+                "category", ImmutableList.of("graphdb", "db"),
+                "tags", ImmutableList.of("graphdb", "gremlin"));
 
         huge.addEdge("related", neo4j, "tags", ImmutableList.of("graphdb"));
 
@@ -7361,17 +7361,17 @@ public class EdgeCoreTest extends BaseCoreTest {
                                       "gremlin").toList();
         });
 
-        List<Edge> edges =  graph.traversal().E()
-                                 .has("related", "tags",
-                                      ConditionP.contains("gremlin"))
-                                 .toList();
+        List<Edge> edges = graph.traversal().E()
+                                .has("related", "tags",
+                                     ConditionP.contains("gremlin"))
+                                .toList();
 
         Assert.assertEquals(1, edges.size());
 
-        edges =  graph.traversal().E()
-                      .has("related",
-                           "tags", ConditionP.contains("graphdb"))
-                      .toList();
+        edges = graph.traversal().E()
+                     .has("related",
+                          "tags", ConditionP.contains("graphdb"))
+                     .toList();
 
         Assert.assertEquals(2, edges.size());
 
@@ -7379,17 +7379,17 @@ public class EdgeCoreTest extends BaseCoreTest {
         huge2janus.property("tags", ImmutableList.of("newTag"));
         graph.tx().commit();
 
-        edges =  graph.traversal().E()
-                      .has("related",
-                           "tags", ConditionP.contains("newTag"))
-                      .toList();
+        edges = graph.traversal().E()
+                     .has("related",
+                          "tags", ConditionP.contains("newTag"))
+                     .toList();
 
         Assert.assertEquals(1, edges.size());
 
-        edges =  graph.traversal().E()
-                      .has("related",
-                           "tags", ConditionP.contains("graphdb"))
-                      .toList();
+        edges = graph.traversal().E()
+                     .has("related",
+                          "tags", ConditionP.contains("graphdb"))
+                     .toList();
 
         Assert.assertEquals(2, edges.size());
 
@@ -7397,10 +7397,10 @@ public class EdgeCoreTest extends BaseCoreTest {
         edges.get(0).remove();
         graph.tx().commit();
 
-        edges =  graph.traversal().E()
-                      .has("related",
-                           "tags", ConditionP.contains("graphdb"))
-                      .toList();
+        edges = graph.traversal().E()
+                     .has("related",
+                          "tags", ConditionP.contains("graphdb"))
+                     .toList();
         Assert.assertEquals(1, edges.size());
     }
 
@@ -7414,9 +7414,9 @@ public class EdgeCoreTest extends BaseCoreTest {
         Vertex james = graph.addVertex(T.label, "author", "id", 1,
                                        "name", "James Gosling", "age", 62,
                                        "lived", "Canadian");
-        Vertex guido =  graph.addVertex(T.label, "author", "id", 2,
-                                        "name", "Guido van Rossum", "age", 61,
-                                        "lived", "California");
+        Vertex guido = graph.addVertex(T.label, "author", "id", 2,
+                                       "name", "Guido van Rossum", "age", 61,
+                                       "lived", "California");
 
         Vertex java = graph.addVertex(T.label, "language", "name", "java");
         Vertex python = graph.addVertex(T.label, "language", "name", "python",
@@ -7516,7 +7516,8 @@ public class EdgeCoreTest extends BaseCoreTest {
             Vertex inVertex,
             Object... kvs) {
         Assert.assertTrue(Utils.contains(edges,
-                          new FakeObjects.FakeEdge(label, outVertex, inVertex, kvs)));
+                                         new FakeObjects.FakeEdge(label, outVertex, inVertex,
+                                                                  kvs)));
     }
 
     private int traverseInPage(Function<String, GraphTraversal<?, ?>> fetcher) {
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeLabelCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeLabelCoreTest.java
index f4494a5d1..3b81c2f16 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeLabelCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/EdgeLabelCoreTest.java
@@ -20,13 +20,6 @@ package org.apache.hugegraph.core;
 import java.util.Date;
 import java.util.List;
 
-import org.apache.tinkerpop.gremlin.process.traversal.P;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.junit.Assume;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -40,6 +33,13 @@ import org.apache.hugegraph.testutil.Assert;
 import org.apache.hugegraph.type.define.Frequency;
 import org.apache.hugegraph.util.DateUtil;
 import org.apache.hugegraph.util.Events;
+import org.apache.tinkerpop.gremlin.process.traversal.P;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.Assume;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableSet;
 
 public class EdgeLabelCoreTest extends SchemaCoreTest {
@@ -164,9 +164,9 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
 
         Assert.assertThrows(IllegalArgumentException.class, () -> {
             schema.edgeLabel("look").multiTimes()
-                    .properties("time")
-                    .sortKeys("time")
-                    .create();
+                  .properties("time")
+                  .sortKeys("time")
+                  .create();
         });
     }
 
@@ -296,10 +296,10 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
         schema.vertexLabel("book").properties("id", "name")
               .primaryKeys("id").create();
         EdgeLabel look = schema.edgeLabel("look")
-                         .properties("time", "weight")
-                         .nullableKeys("weight")
-                         .link("person", "book")
-                         .create();
+                               .properties("time", "weight")
+                               .nullableKeys("weight")
+                               .link("person", "book")
+                               .create();
 
         Assert.assertNotNull(look);
         Assert.assertEquals("look", look.name());
@@ -437,7 +437,7 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
     @Test
     public void testAddEdgeLabelWithDisableLabelIndex() {
         super.initPropertyKeys();
-        HugeGraph graph =  graph();
+        HugeGraph graph = graph();
         SchemaManager schema = graph.schema();
 
         schema.vertexLabel("person")
@@ -602,8 +602,8 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
               .create();
 
         EdgeLabel look = schema.edgeLabel("look")
-                         .nullableKeys("weight")
-                         .append();
+                               .nullableKeys("weight")
+                               .append();
 
         Assert.assertNotNull(look);
         Assert.assertEquals("look", look.name());
@@ -633,9 +633,9 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
               .create();
 
         EdgeLabel look = schema.edgeLabel("look")
-                         .properties("weight")
-                         .nullableKeys("weight")
-                         .append();
+                               .properties("weight")
+                               .nullableKeys("weight")
+                               .append();
 
         Assert.assertNotNull(look);
         Assert.assertEquals("look", look.name());
@@ -993,8 +993,8 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
             graph().traversal().E().hasLabel("read").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
@@ -1022,8 +1022,8 @@ public class EdgeLabelCoreTest extends SchemaCoreTest {
             graph().traversal().E().hasLabel("read").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/IndexLabelCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/IndexLabelCoreTest.java
index 07b450625..24a905427 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/IndexLabelCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/IndexLabelCoreTest.java
@@ -20,13 +20,6 @@ package org.apache.hugegraph.core;
 import java.util.Date;
 import java.util.List;
 
-import org.apache.tinkerpop.gremlin.process.traversal.P;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.junit.Assume;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.exception.ExistedException;
@@ -42,6 +35,13 @@ import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.IndexType;
 import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.DateUtil;
+import org.apache.tinkerpop.gremlin.process.traversal.P;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.Assume;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableList;
 
 public class IndexLabelCoreTest extends SchemaCoreTest {
@@ -113,7 +113,7 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         Assert.assertEquals(11, person.indexLabels().size());
         assertContainsIl(person.indexLabels(),
                          "personByName", "personByCity", "personByAge",
-                         "personByBorn", "personByFans","personByHeight",
+                         "personByBorn", "personByFans", "personByHeight",
                          "personByWeight", "personByIdNo", "personByTags",
                          "personByCategory", "personByScore");
 
@@ -411,7 +411,7 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
                   .by("age").search().create();
         }, e -> {
             Assert.assertTrue(e.getMessage(), e.getMessage().contains(
-                              "Search index can only build on text"));
+                    "Search index can only build on text"));
         });
 
         Assert.assertThrows(IllegalArgumentException.class, () -> {
@@ -1257,10 +1257,10 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         graph().tx().commit();
 
         Vertex vertex = graph().traversal().V().hasLabel("person")
-                        .has("city", "Hongkong").next();
+                               .has("city", "Hongkong").next();
         Assert.assertNotNull(vertex);
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
 
         schema.indexLabel("personByCity").remove();
@@ -1279,7 +1279,7 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
                    .has("city", "Hongkong").next();
         });
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
 
         schema.indexLabel("personByAge").remove();
@@ -1322,11 +1322,11 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         Assert.assertEquals(1, authored.indexLabels().size());
         assertContainsIl(authored.indexLabels(), "authoredByContri");
 
-        james.addEdge("authored", java1,"contribution", "test");
+        james.addEdge("authored", java1, "contribution", "test");
         graph().tx().commit();
 
         Edge edge = graph().traversal().E().hasLabel("authored")
-                    .has("contribution", "test").next();
+                           .has("contribution", "test").next();
         Assert.assertNotNull(edge);
 
         schema.indexLabel("authoredByContri").remove();
@@ -1375,20 +1375,20 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         graph().tx().commit();
 
         Vertex vertex = graph().traversal().V().hasLabel("person")
-                        .has("city", "Hongkong").next();
+                               .has("city", "Hongkong").next();
         Assert.assertNotNull(vertex);
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
 
         schema.indexLabel("personByCity").rebuild();
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("city", "Hongkong").next();
+                        .has("city", "Hongkong").next();
         Assert.assertNotNull(vertex);
 
         schema.indexLabel("personByAge").rebuild();
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
     }
 
@@ -1414,18 +1414,18 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         graph().tx().commit();
 
         Vertex vertex = graph().traversal().V().hasLabel("person")
-                        .has("city", "Hongkong").next();
+                               .has("city", "Hongkong").next();
         Assert.assertNotNull(vertex);
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
 
         schema.vertexLabel("person").rebuildIndex();
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("city", "Hongkong").next();
+                        .has("city", "Hongkong").next();
         Assert.assertNotNull(vertex);
         vertex = graph().traversal().V().hasLabel("person")
-                 .has("age", P.inside(2, 4)).next();
+                        .has("age", P.inside(2, 4)).next();
         Assert.assertNotNull(vertex);
     }
 
@@ -1454,11 +1454,11 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         Assert.assertEquals(1, authored.indexLabels().size());
         assertContainsIl(authored.indexLabels(), "authoredByContri");
 
-        james.addEdge("authored", java1,"contribution", "test");
+        james.addEdge("authored", java1, "contribution", "test");
         graph().tx().commit();
 
         Edge edge = graph().traversal().E().hasLabel("authored")
-                    .has("contribution", "test").next();
+                           .has("contribution", "test").next();
         Assert.assertNotNull(edge);
 
         schema.indexLabel("authoredByContri").rebuild();
@@ -1466,7 +1466,7 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         assertContainsIl(authored.indexLabels(), "authoredByContri");
 
         edge = graph().traversal().E().hasLabel("authored")
-               .has("contribution", "test").next();
+                      .has("contribution", "test").next();
         Assert.assertNotNull(edge);
     }
 
@@ -1495,18 +1495,18 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
         Assert.assertEquals(1, authored.indexLabels().size());
         assertContainsIl(authored.indexLabels(), "authoredByContri");
 
-        james.addEdge("authored", java1,"contribution", "test");
+        james.addEdge("authored", java1, "contribution", "test");
         graph().tx().commit();
 
         Edge edge = graph().traversal().E().hasLabel("authored")
-                    .has("contribution", "test").next();
+                           .has("contribution", "test").next();
         Assert.assertNotNull(edge);
 
         schema.edgeLabel("authored").rebuildIndex();
         Assert.assertEquals(1, authored.indexLabels().size());
         assertContainsIl(authored.indexLabels(), "authoredByContri");
         edge = graph().traversal().E().hasLabel("authored")
-               .has("contribution", "test").next();
+                      .has("contribution", "test").next();
         Assert.assertNotNull(edge);
     }
 
@@ -1522,8 +1522,8 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
             graph().traversal().V().hasLabel("reader").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
@@ -1550,8 +1550,8 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
             graph().traversal().E().hasLabel("read").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
@@ -1579,8 +1579,8 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
             graph().traversal().V().hasLabel("reader").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
@@ -1607,8 +1607,8 @@ public class IndexLabelCoreTest extends SchemaCoreTest {
             graph().traversal().E().hasLabel("read").toList();
         }, e -> {
             Assert.assertTrue(
-                   e.getMessage().startsWith("Don't accept query by label") &&
-                   e.getMessage().endsWith("label index is disabled"));
+                    e.getMessage().startsWith("Don't accept query by label") &&
+                    e.getMessage().endsWith("label index is disabled"));
         });
 
         // Query by property index is ok
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyCoreTest.java
index 7ae47faa4..873efd5e8 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyCoreTest.java
@@ -25,19 +25,19 @@ import java.util.List;
 import java.util.Set;
 import java.util.UUID;
 
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.hugegraph.testutil.Utils;
-import org.junit.Before;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.testutil.Assert;
+import org.apache.hugegraph.testutil.Utils;
 import org.apache.hugegraph.traversal.optimize.TraversalUtil;
 import org.apache.hugegraph.util.Blob;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.Before;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -171,9 +171,9 @@ public abstract class PropertyCoreTest extends BaseCoreTest {
 
             vertex = graph.vertices(vertex.id()).next();
             Assert.assertTrue(TraversalUtil.testProperty(vertex.property(key),
-                                            ImmutableSet.copyOf(values)));
+                                                         ImmutableSet.copyOf(values)));
             Assert.assertFalse(TraversalUtil.testProperty(vertex.property(key),
-                                             ImmutableList.copyOf(values)));
+                                                          ImmutableList.copyOf(values)));
             return vertex.value(key);
         }
     }
@@ -223,9 +223,9 @@ public abstract class PropertyCoreTest extends BaseCoreTest {
 
             edge = graph.edges(edge.id()).next();
             Assert.assertTrue(TraversalUtil.testProperty(edge.property(key),
-                                            ImmutableSet.copyOf(values)));
+                                                         ImmutableSet.copyOf(values)));
             Assert.assertFalse(TraversalUtil.testProperty(edge.property(key),
-                                             ImmutableList.copyOf(values)));
+                                                          ImmutableList.copyOf(values)));
             return edge.value(key);
         }
     }
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyKeyCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyKeyCoreTest.java
index b7109646f..5cd1193fc 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyKeyCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/PropertyKeyCoreTest.java
@@ -19,9 +19,6 @@ package org.apache.hugegraph.core;
 
 import java.util.Date;
 
-import org.junit.Assume;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.exception.NotAllowException;
@@ -35,6 +32,9 @@ import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
 import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.DateUtil;
+import org.junit.Assume;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableList;
 
 public class PropertyKeyCoreTest extends SchemaCoreTest {
@@ -43,9 +43,9 @@ public class PropertyKeyCoreTest extends SchemaCoreTest {
     public void testAddPropertyKey() {
         SchemaManager schema = graph().schema();
         PropertyKey id = schema.propertyKey("id")
-                         .asText()
-                         .valueSingle()
-                         .create();
+                               .asText()
+                               .valueSingle()
+                               .create();
 
         Assert.assertEquals("id", id.name());
         Assert.assertEquals(DataType.TEXT, id.dataType());
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RamTableTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RamTableTest.java
index 201df527a..a47d5bdc9 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RamTableTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RamTableTest.java
@@ -22,16 +22,6 @@ import java.nio.file.Paths;
 import java.util.Iterator;
 
 import org.apache.commons.io.FileUtils;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.junit.After;
-import org.junit.Assume;
-import org.junit.Before;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -44,6 +34,15 @@ import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.testutil.Assert;
 import org.apache.hugegraph.testutil.Whitebox;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.After;
+import org.junit.Assume;
+import org.junit.Before;
+import org.junit.Test;
 
 public class RamTableTest extends BaseCoreTest {
 
@@ -67,13 +66,13 @@ public class RamTableTest extends BaseCoreTest {
         graph.schema().vertexLabel("vl1").useCustomizeNumberId().create();
         graph.schema().vertexLabel("vl2").useCustomizeNumberId().create();
         graph.schema().edgeLabel("el1")
-                      .sourceLabel("vl1")
-                      .targetLabel("vl1")
-                      .create();
+             .sourceLabel("vl1")
+             .targetLabel("vl1")
+             .create();
         graph.schema().edgeLabel("el2")
-                      .sourceLabel("vl2")
-                      .targetLabel("vl2")
-                      .create();
+             .sourceLabel("vl2")
+             .targetLabel("vl2")
+             .create();
     }
 
     @Override
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RestoreCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RestoreCoreTest.java
index 23b3eb65f..0713fb022 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RestoreCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RestoreCoreTest.java
@@ -17,16 +17,15 @@
 
 package org.apache.hugegraph.core;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.junit.After;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.testutil.Assert;
 import org.apache.hugegraph.type.define.GraphMode;
 import org.apache.hugegraph.type.define.IdStrategy;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.junit.After;
+import org.junit.Test;
 
 public class RestoreCoreTest extends BaseCoreTest {
 
@@ -42,7 +41,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().vertexLabel("person").id(0L).create()
+                graph.schema().vertexLabel("person").id(0L).create()
         );
     }
 
@@ -51,7 +50,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().vertexLabel("person").id(0L).create()
+                graph.schema().vertexLabel("person").id(0L).create()
         );
     }
 
@@ -60,7 +59,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().vertexLabel("person").id(0L).create()
+                graph.schema().vertexLabel("person").id(0L).create()
         );
     }
 
@@ -69,7 +68,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("person").id(-100L).create()
+                graph.schema().vertexLabel("person").id(-100L).create()
         );
     }
 
@@ -78,7 +77,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("person").id(-100L).create()
+                graph.schema().vertexLabel("person").id(-100L).create()
         );
     }
 
@@ -87,7 +86,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("person").id(-100L).create()
+                graph.schema().vertexLabel("person").id(-100L).create()
         );
     }
 
@@ -96,7 +95,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("person").id(100L).create()
+                graph.schema().vertexLabel("person").id(100L).create()
         );
     }
 
@@ -105,7 +104,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("person").id(100L).create()
+                graph.schema().vertexLabel("person").id(100L).create()
         );
     }
 
@@ -129,7 +128,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         graph.mode(GraphMode.RESTORING);
         graph.schema().vertexLabel("person").id(100L).create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().vertexLabel("person").id(100L).create()
+                graph.schema().vertexLabel("person").id(100L).create()
         );
     }
 
@@ -139,7 +138,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         graph.mode(GraphMode.RESTORING);
         graph.schema().vertexLabel("person").id(100L).create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().vertexLabel("person1").id(100L).create()
+                graph.schema().vertexLabel("person1").id(100L).create()
         );
     }
 
@@ -148,7 +147,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().vertexLabel("~person").id(0L).create()
+                graph.schema().vertexLabel("~person").id(0L).create()
         );
     }
 
@@ -157,7 +156,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().vertexLabel("~person").id(100L).build()
+                graph.schema().vertexLabel("~person").id(100L).build()
         );
     }
 
@@ -175,7 +174,7 @@ public class RestoreCoreTest extends BaseCoreTest {
              .idStrategy(IdStrategy.AUTOMATIC).create();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.addVertex(T.label, "person", T.id, 100L)
+                graph.addVertex(T.label, "person", T.id, 100L)
         );
     }
 
@@ -205,7 +204,7 @@ public class RestoreCoreTest extends BaseCoreTest {
              .idStrategy(IdStrategy.PRIMARY_KEY).primaryKeys("name").create();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
+                graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
         );
     }
 
@@ -217,7 +216,7 @@ public class RestoreCoreTest extends BaseCoreTest {
              .idStrategy(IdStrategy.PRIMARY_KEY).primaryKeys("name").create();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
+                graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
         );
     }
 
@@ -229,7 +228,7 @@ public class RestoreCoreTest extends BaseCoreTest {
              .idStrategy(IdStrategy.PRIMARY_KEY).primaryKeys("name").create();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
+                graph.addVertex(T.label, "person", T.id, 100L, "name", "Tom")
         );
     }
 
@@ -419,17 +418,17 @@ public class RestoreCoreTest extends BaseCoreTest {
 
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(UnsupportedOperationException.class, () ->
-            v1.addEdge("knows", v2, T.id, "id")
+                v1.addEdge("knows", v2, T.id, "id")
         );
 
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(UnsupportedOperationException.class, () ->
-            v1.addEdge("knows", v2, T.id, "id")
+                v1.addEdge("knows", v2, T.id, "id")
         );
 
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(UnsupportedOperationException.class, () ->
-            v1.addEdge("knows", v2, T.id, "id")
+                v1.addEdge("knows", v2, T.id, "id")
         );
     }
 
@@ -438,7 +437,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().propertyKey("name").id(0L).create()
+                graph.schema().propertyKey("name").id(0L).create()
         );
     }
 
@@ -447,7 +446,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().propertyKey("name").id(0L).create()
+                graph.schema().propertyKey("name").id(0L).create()
         );
     }
 
@@ -456,7 +455,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().propertyKey("name").id(0L).create()
+                graph.schema().propertyKey("name").id(0L).create()
         );
     }
 
@@ -465,7 +464,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().propertyKey("name").id(-100L).create()
+                graph.schema().propertyKey("name").id(-100L).create()
         );
     }
 
@@ -474,7 +473,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().propertyKey("name").id(-100L).create()
+                graph.schema().propertyKey("name").id(-100L).create()
         );
     }
 
@@ -483,7 +482,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().propertyKey("name").id(-100L).create()
+                graph.schema().propertyKey("name").id(-100L).create()
         );
     }
 
@@ -492,7 +491,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().propertyKey("name").id(100L).create()
+                graph.schema().propertyKey("name").id(100L).create()
         );
     }
 
@@ -501,7 +500,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         HugeGraph graph = graph();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().propertyKey("name").id(100L).create()
+                graph.schema().propertyKey("name").id(100L).create()
 
         );
     }
@@ -527,7 +526,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         graph.mode(GraphMode.RESTORING);
         graph.schema().propertyKey("name").id(100L).create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().propertyKey("name").id(1000L).create()
+                graph.schema().propertyKey("name").id(1000L).create()
         );
     }
 
@@ -537,7 +536,7 @@ public class RestoreCoreTest extends BaseCoreTest {
         graph.mode(GraphMode.RESTORING);
         graph.schema().propertyKey("name").id(100L).create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().propertyKey("name1").id(100L).create()
+                graph.schema().propertyKey("name1").id(100L).create()
         );
     }
 
@@ -550,9 +549,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(0L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(0L)
+                     .create()
         );
     }
 
@@ -565,9 +564,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(0L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(0L)
+                     .create()
         );
     }
 
@@ -580,9 +579,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalArgumentException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(0L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(0L)
+                     .create()
         );
     }
 
@@ -595,9 +594,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(-100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(-100L)
+                     .create()
         );
     }
 
@@ -610,9 +609,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(-100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(-100L)
+                     .create()
         );
     }
 
@@ -625,9 +624,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.RESTORING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(-100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(-100L)
+                     .create()
         );
     }
 
@@ -640,9 +639,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.NONE);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(100L)
+                     .create()
         );
     }
 
@@ -655,9 +654,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .primaryKeys("name").create();
         graph.mode(GraphMode.MERGING);
         Assert.assertThrows(IllegalStateException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(100L)
+                     .create()
         );
     }
 
@@ -699,9 +698,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .onV("person").by("city").secondary().id(100L)
              .create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().indexLabel("personByCity")
-                 .onV("person").by("city").secondary().id(100L)
-                 .create()
+                graph.schema().indexLabel("personByCity")
+                     .onV("person").by("city").secondary().id(100L)
+                     .create()
         );
     }
 
@@ -717,9 +716,9 @@ public class RestoreCoreTest extends BaseCoreTest {
              .onV("person").by("city").secondary().id(100L)
              .create();
         Assert.assertThrows(ExistedException.class, () ->
-            graph.schema().indexLabel("personByCity1")
-                 .onV("person").by("city").secondary().id(100L)
-                 .create()
+                graph.schema().indexLabel("personByCity1")
+                     .onV("person").by("city").secondary().id(100L)
+                     .create()
         );
     }
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RoleElectionStateMachineTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RoleElectionStateMachineTest.java
index e4a3c4f50..eab1e6b79 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RoleElectionStateMachineTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/RoleElectionStateMachineTest.java
@@ -206,7 +206,7 @@ public class RoleElectionStateMachineTest {
         };
 
         final List<ClusterRole> clusterRoleLogs = Collections.synchronizedList(
-                                                  new ArrayList<>(100));
+                new ArrayList<>(100));
 
         final ClusterRoleStore clusterRoleStore = new ClusterRoleStore() {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/SchemaCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/SchemaCoreTest.java
index 45980b378..0d70bb203 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/SchemaCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/SchemaCoreTest.java
@@ -21,9 +21,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.EdgeLabel;
@@ -32,6 +29,8 @@ import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.testutil.Assert;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 
 public class SchemaCoreTest extends BaseCoreTest {
 
diff --git a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/TaskCoreTest.java b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/TaskCoreTest.java
index 1c63e8c15..1a6738a8e 100644
--- a/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/TaskCoreTest.java
+++ b/hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/core/TaskCoreTest.java
@@ -22,9 +22,6 @@ import java.util.Iterator;
 import java.util.Random;
 import java.util.concurrent.TimeoutException;
 
-import org.junit.Before;
-import org.junit.Test;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.api.job.GremlinAPI.GremlinRequest;
@@ -41,6 +38,9 @@ import org.apache.hugegraph.task.TaskScheduler;
 import org.apache.hugegraph.task.TaskStatus;
 import org.apache.hugegraph.testutil.Assert;
 import org.apache.hugegraph.testutil.Whitebox;
+import org.junit.Before;
+import org.junit.Test;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
@@ -249,20 +249,22 @@ public class TaskCoreTest extends BaseCoreTest {
         TaskScheduler scheduler = graph.taskScheduler();
 
         String script = "schema=graph.schema();" +
-                "schema.propertyKey('name').asText().ifNotExist().create();" +
-                "schema.propertyKey('age').asInt().ifNotExist().create();" +
-                "schema.propertyKey('lang').asText().ifNotExist().create();" +
-                "schema.propertyKey('date').asDate().ifNotExist().create();" +
-                "schema.propertyKey('price').asInt().ifNotExist().create();" +
-                "schema.vertexLabel('person1').properties('name','age').ifNotExist().create();" +
-                "schema.vertexLabel('person2').properties('name','age').ifNotExist().create();" +
-                "schema.edgeLabel('knows').sourceLabel('person1').targetLabel('person2')." +
-                "properties('date').ifNotExist().create();" +
-                "for(int i = 0; i < 1000; i++) {" +
-                "  p1=graph.addVertex(T.label,'person1','name','p1-'+i,'age',29);" +
-                "  p2=graph.addVertex(T.label,'person2','name','p2-'+i,'age',27);" +
-                "  p1.addEdge('knows',p2,'date','2016-01-10');" +
-                "}";
+                        "schema.propertyKey('name').asText().ifNotExist().create();" +
+                        "schema.propertyKey('age').asInt().ifNotExist().create();" +
+                        "schema.propertyKey('lang').asText().ifNotExist().create();" +
+                        "schema.propertyKey('date').asDate().ifNotExist().create();" +
+                        "schema.propertyKey('price').asInt().ifNotExist().create();" +
+                        "schema.vertexLabel('person1').properties('name','age').ifNotExist()" +
+                        ".create();" +
+                        "schema.vertexLabel('person2').properties('name','age').ifNotExist()" +
+                        ".create();" +
+                        "schema.edgeLabel('knows').sourceLabel('person1').targetLabel('person2')." +
+                        "properties('date').ifNotExist().create();" +
+                        "for(int i = 0; i < 1000; i++) {" +
+                        "  p1=graph.addVertex(T.label,'person1','name','p1-'+i,'age',29);" +
+                        "  p2=graph.addVertex(T.label,'person2','name','p2-'+i,'age',27);" +
+                        "  p1.addEdge('knows',p2,'date','2016-01-10');" +
+                        "}";
 
         HugeTask<Object> task = runGremlinJob(script);
         task = scheduler.waitUntilTaskCompleted(task.id(), 10);
@@ -308,27 +310,27 @@ public class TaskCoreTest extends BaseCoreTest {
         TaskScheduler scheduler = graph.taskScheduler();
 
         String script = "schema=graph.schema();" +
-                "schema.propertyKey('name').asText().ifNotExist().create();" +
-                "schema.vertexLabel('char').useCustomizeNumberId()" +
-                "      .properties('name').ifNotExist().create();" +
-                "schema.edgeLabel('next').sourceLabel('char').targetLabel('char')" +
-                "      .properties('name').ifNotExist().create();" +
-                "g.addV('char').property(id,1).property('name','A').as('a')" +
-                " .addV('char').property(id,2).property('name','B').as('b')" +
-                " .addV('char').property(id,3).property('name','C').as('c')" +
-                " .addV('char').property(id,4).property('name','D').as('d')" +
-                " .addV('char').property(id,5).property('name','E').as('e')" +
-                " .addV('char').property(id,6).property('name','F').as('f')" +
-                " .addE('next').from('a').to('b').property('name','ab')" +
... 3741 lines suppressed ...


(incubator-hugegraph) 02/03: fix: format and clean code in core module (#2440)

Posted by vg...@apache.org.
This is an automated email from the ASF dual-hosted git repository.

vgalaxies pushed a commit to branch pd-store
in repository https://gitbox.apache.org/repos/asf/incubator-hugegraph.git

commit 960b7330fd8860d6dd7f56b063a874a37e13fa84
Author: M <87...@users.noreply.github.com>
AuthorDate: Tue Feb 20 17:22:28 2024 +0800

    fix: format and clean code in core module (#2440)
---
 .../java/org/apache/hugegraph/HugeFactory.java     |   3 +-
 .../main/java/org/apache/hugegraph/HugeGraph.java  |   6 +-
 .../java/org/apache/hugegraph/HugeGraphParams.java |   9 +-
 .../org/apache/hugegraph/StandardHugeGraph.java    |  72 +++++-----
 .../apache/hugegraph/analyzer/AnalyzerFactory.java |   6 +-
 .../apache/hugegraph/analyzer/AnsjAnalyzer.java    |   8 +-
 .../apache/hugegraph/analyzer/HanLPAnalyzer.java   |  23 ++--
 .../org/apache/hugegraph/analyzer/IKAnalyzer.java  |   8 +-
 .../apache/hugegraph/analyzer/JcsegAnalyzer.java   |   8 +-
 .../apache/hugegraph/analyzer/JiebaAnalyzer.java   |   5 +-
 .../apache/hugegraph/analyzer/MMSeg4JAnalyzer.java |   7 +-
 .../apache/hugegraph/analyzer/SmartCNAnalyzer.java |   5 +-
 .../org/apache/hugegraph/auth/AuthManager.java     |   2 +-
 .../org/apache/hugegraph/auth/EntityManager.java   |  16 +--
 .../java/org/apache/hugegraph/auth/HugeAccess.java |   7 +-
 .../java/org/apache/hugegraph/auth/HugeBelong.java |  15 +--
 .../java/org/apache/hugegraph/auth/HugeGroup.java  |   9 +-
 .../org/apache/hugegraph/auth/HugeProject.java     |   7 +-
 .../org/apache/hugegraph/auth/HugeResource.java    |  19 +--
 .../java/org/apache/hugegraph/auth/HugeTarget.java |   9 +-
 .../java/org/apache/hugegraph/auth/HugeUser.java   |   7 +-
 .../apache/hugegraph/auth/RelationshipManager.java |  18 +--
 .../org/apache/hugegraph/auth/ResourceObject.java  |   2 +-
 .../org/apache/hugegraph/auth/ResourceType.java    |   9 +-
 .../org/apache/hugegraph/auth/RolePermission.java  |  26 ++--
 .../org/apache/hugegraph/auth/SchemaDefine.java    |  12 +-
 .../apache/hugegraph/auth/StandardAuthManager.java |  16 +--
 .../org/apache/hugegraph/auth/TokenGenerator.java  |   2 +-
 .../apache/hugegraph/backend/BackendException.java |   2 +-
 .../hugegraph/backend/cache/AbstractCache.java     |   5 +-
 .../hugegraph/backend/cache/CacheManager.java      |   7 +-
 .../hugegraph/backend/cache/CacheNotifier.java     |   8 +-
 .../backend/cache/CachedBackendStore.java          |   2 +-
 .../backend/cache/CachedGraphTransaction.java      |   9 +-
 .../backend/cache/CachedSchemaTransaction.java     |   9 +-
 .../hugegraph/backend/cache/OffheapCache.java      |  23 ++--
 .../apache/hugegraph/backend/cache/RamCache.java   |  12 +-
 .../org/apache/hugegraph/backend/id/EdgeId.java    |  40 +++---
 .../org/apache/hugegraph/backend/id/IdUtil.java    |   1 -
 .../hugegraph/backend/id/SnowflakeIdGenerator.java |  13 +-
 .../hugegraph/backend/id/SplicingIdGenerator.java  |  18 ++-
 .../apache/hugegraph/backend/page/IdHolder.java    |   7 +-
 .../hugegraph/backend/page/PageEntryIterator.java  |   3 +-
 .../org/apache/hugegraph/backend/page/PageIds.java |   1 +
 .../apache/hugegraph/backend/page/QueryList.java   |  26 ++--
 .../backend/page/SortByCountIdHolderList.java      |   3 +-
 .../backend/query/BatchConditionQuery.java         |   2 +-
 .../apache/hugegraph/backend/query/Condition.java  |  44 ++++---
 .../hugegraph/backend/query/ConditionQuery.java    |  19 +--
 .../backend/query/ConditionQueryFlatten.java       |   2 +-
 .../apache/hugegraph/backend/query/IdQuery.java    |   3 +-
 .../org/apache/hugegraph/backend/query/Query.java  |   8 +-
 .../hugegraph/backend/query/QueryResults.java      |  13 +-
 .../backend/serializer/AbstractSerializer.java     |   8 +-
 .../serializer/BinaryScatterSerializer.java        |   2 +-
 .../backend/serializer/BinarySerializer.java       |  29 ++---
 .../hugegraph/backend/serializer/BytesBuffer.java  |  16 +--
 .../backend/serializer/GraphSerializer.java        |   3 +-
 .../backend/serializer/MergeIterator.java          |   4 +-
 .../backend/serializer/SerializerFactory.java      |   2 +-
 .../backend/serializer/TableBackendEntry.java      |   1 -
 .../backend/serializer/TableSerializer.java        |  21 +--
 .../backend/serializer/TextBackendEntry.java       |   3 +-
 .../backend/serializer/TextSerializer.java         |  27 ++--
 .../backend/store/AbstractBackendStore.java        |   8 +-
 .../store/AbstractBackendStoreProvider.java        |  10 +-
 .../backend/store/BackendEntryIterator.java        |   1 -
 .../hugegraph/backend/store/BackendMutation.java   |  41 +++---
 .../backend/store/BackendProviderFactory.java      |   7 +-
 .../backend/store/BackendSessionPool.java          |   5 +-
 .../hugegraph/backend/store/BackendStore.java      |   9 +-
 .../hugegraph/backend/store/BackendStoreInfo.java  |   3 +-
 .../backend/store/BackendStoreProvider.java        |   3 +-
 .../hugegraph/backend/store/BackendTable.java      |   4 +-
 .../hugegraph/backend/store/TableDefine.java       |   1 +
 .../backend/store/memory/InMemoryDBStore.java      |  12 +-
 .../store/memory/InMemoryDBStoreProvider.java      |   2 +-
 .../backend/store/memory/InMemoryDBTable.java      |  24 ++--
 .../backend/store/memory/InMemoryDBTables.java     |  51 ++++----
 .../backend/store/memory/InMemoryMetrics.java      |   1 +
 .../backend/store/raft/RaftBackendStore.java       |  18 +--
 .../store/raft/RaftBackendStoreProvider.java       |   7 +-
 .../hugegraph/backend/store/raft/RaftClosure.java  |   4 +-
 .../hugegraph/backend/store/raft/RaftContext.java  |  44 +++----
 .../backend/store/raft/RaftException.java          |   2 +-
 .../backend/store/raft/RaftGroupManagerImpl.java   |  20 ++-
 .../hugegraph/backend/store/raft/RaftNode.java     |  26 ++--
 .../hugegraph/backend/store/raft/RaftResult.java   |   3 +-
 .../backend/store/raft/StoreSerializer.java        |   2 +-
 .../backend/store/raft/StoreSnapshotFile.java      |   2 +-
 .../backend/store/raft/StoreStateMachine.java      |  22 ++--
 .../raft/compress/CompressStrategyManager.java     |   6 +-
 .../raft/compress/ParallelCompressStrategy.java    |  16 +--
 .../backend/store/raft/rpc/AddPeerProcessor.java   |  11 +-
 .../backend/store/raft/rpc/ListPeersProcessor.java |  12 +-
 .../store/raft/rpc/RemovePeerProcessor.java        |  11 +-
 .../backend/store/raft/rpc/RpcForwarder.java       |  41 +++---
 .../backend/store/raft/rpc/SetLeaderProcessor.java |   4 +-
 .../store/raft/rpc/StoreCommandProcessor.java      |  10 +-
 .../hugegraph/backend/store/ram/RamTable.java      |   8 +-
 .../hugegraph/backend/tx/AbstractTransaction.java  |  16 +--
 .../backend/tx/GraphIndexTransaction.java          | 145 +++++++++++----------
 .../hugegraph/backend/tx/GraphTransaction.java     |  93 +++++++------
 .../hugegraph/backend/tx/IndexableTransaction.java |   4 +-
 .../backend/tx/SchemaIndexTransaction.java         |   7 +-
 .../hugegraph/backend/tx/SchemaTransaction.java    |  39 +++---
 .../org/apache/hugegraph/config/CoreOptions.java   |  40 +++---
 .../apache/hugegraph/io/HugeGraphIoRegistry.java   |   2 +-
 .../apache/hugegraph/io/HugeGraphSONModule.java    |  65 +++++----
 .../org/apache/hugegraph/io/HugeGryoModule.java    |   2 +-
 .../java/org/apache/hugegraph/job/ComputerJob.java |   2 +-
 .../apache/hugegraph/job/EphemeralJobBuilder.java  |   2 +-
 .../java/org/apache/hugegraph/job/GremlinJob.java  |  12 +-
 .../java/org/apache/hugegraph/job/JobBuilder.java  |   2 +-
 .../hugegraph/job/algorithm/AbstractAlgorithm.java |  30 ++---
 .../hugegraph/job/algorithm/AlgorithmPool.java     |   6 +-
 .../hugegraph/job/algorithm/BfsTraverser.java      |   7 +-
 .../apache/hugegraph/job/algorithm/Consumers.java  |   5 +-
 .../job/algorithm/CountEdgeAlgorithm.java          |   3 +-
 .../job/algorithm/CountVertexAlgorithm.java        |   3 +-
 .../job/algorithm/SubgraphStatAlgorithm.java       |  14 +-
 .../job/algorithm/cent/AbstractCentAlgorithm.java  |  53 ++++----
 .../cent/BetweennessCentralityAlgorithm.java       |  13 +-
 .../cent/BetweennessCentralityAlgorithmV2.java     |   5 +-
 .../cent/ClosenessCentralityAlgorithm.java         |   9 +-
 .../cent/ClosenessCentralityAlgorithmV2.java       |   8 +-
 .../algorithm/cent/DegreeCentralityAlgorithm.java  |   5 +-
 .../cent/EigenvectorCentralityAlgorithm.java       |   5 +-
 .../algorithm/cent/StressCentralityAlgorithm.java  |   7 +-
 .../cent/StressCentralityAlgorithmV2.java          |   3 +-
 .../comm/ClusterCoefficientAlgorithm.java          |   2 +-
 .../job/algorithm/comm/KCoreAlgorithm.java         |  15 ++-
 .../job/algorithm/comm/LouvainAlgorithm.java       |   4 +-
 .../job/algorithm/comm/LouvainTraverser.java       |  38 +++---
 .../hugegraph/job/algorithm/comm/LpaAlgorithm.java |   6 +-
 .../job/algorithm/comm/WeakConnectedComponent.java |  21 +--
 .../job/algorithm/rank/PageRankAlgorithm.java      |  31 +++--
 .../similarity/FusiformSimilarityAlgorithm.java    |  15 +--
 .../hugegraph/job/computer/AbstractComputer.java   |  20 +--
 .../hugegraph/job/computer/LouvainComputer.java    |   5 +-
 .../apache/hugegraph/job/computer/LpaComputer.java |   3 +-
 .../hugegraph/job/computer/PageRankComputer.java   |   3 +-
 .../job/computer/TriangleCountComputer.java        |   2 +-
 .../computer/WeakConnectedComponentComputer.java   |   2 +-
 .../hugegraph/job/schema/EdgeLabelRemoveJob.java   |   3 +-
 .../hugegraph/job/schema/IndexLabelRebuildJob.java |  16 +--
 .../hugegraph/job/schema/IndexLabelRemoveJob.java  |   2 +-
 .../job/schema/OlapPropertyKeyClearJob.java        |   2 +-
 .../org/apache/hugegraph/job/schema/SchemaJob.java |  27 ++--
 .../hugegraph/job/schema/VertexLabelRemoveJob.java |  11 +-
 .../job/system/DeleteExpiredElementJob.java        |   2 +-
 .../job/system/DeleteExpiredIndexJob.java          |   4 +-
 .../hugegraph/job/system/DeleteExpiredJob.java     |   9 +-
 .../apache/hugegraph/job/system/JobCounters.java   |   4 +-
 .../hugegraph/masterelection/ClusterRole.java      |   8 +-
 .../masterelection/RoleElectionOptions.java        |   2 +-
 .../masterelection/StandardRoleListener.java       |   2 +-
 .../hugegraph/plugin/HugeGraphGremlinPlugin.java   |   6 +-
 .../apache/hugegraph/plugin/HugeGraphPlugin.java   |   2 +-
 .../org/apache/hugegraph/schema/EdgeLabel.java     |   6 +-
 .../org/apache/hugegraph/schema/IndexLabel.java    |  19 +--
 .../org/apache/hugegraph/schema/PropertyKey.java   |  27 ++--
 .../org/apache/hugegraph/schema/SchemaElement.java |  10 +-
 .../org/apache/hugegraph/schema/SchemaLabel.java   |  15 ++-
 .../org/apache/hugegraph/schema/SchemaManager.java |  22 ++--
 .../java/org/apache/hugegraph/schema/Userdata.java |   6 +-
 .../org/apache/hugegraph/schema/VertexLabel.java   |   2 +-
 .../hugegraph/schema/builder/AbstractBuilder.java  |   6 +-
 .../hugegraph/schema/builder/EdgeLabelBuilder.java |  55 ++++----
 .../schema/builder/IndexLabelBuilder.java          |  11 +-
 .../schema/builder/PropertyKeyBuilder.java         |  48 ++++---
 .../schema/builder/VertexLabelBuilder.java         |  47 +++----
 .../hugegraph/security/HugeSecurityManager.java    |  56 ++++----
 .../org/apache/hugegraph/structure/GraphType.java  |   1 +
 .../org/apache/hugegraph/structure/HugeEdge.java   |   8 +-
 .../hugegraph/structure/HugeEdgeProperty.java      |   3 +-
 .../apache/hugegraph/structure/HugeElement.java    |  14 +-
 .../apache/hugegraph/structure/HugeFeatures.java   |  18 +--
 .../org/apache/hugegraph/structure/HugeIndex.java  |   2 +-
 .../apache/hugegraph/structure/HugeProperty.java   |   3 +-
 .../org/apache/hugegraph/structure/HugeVertex.java |  13 +-
 .../hugegraph/structure/HugeVertexProperty.java    |   9 +-
 .../apache/hugegraph/task/EphemeralJobQueue.java   |   6 +-
 .../org/apache/hugegraph/task/HugeServerInfo.java  |  22 ++--
 .../java/org/apache/hugegraph/task/HugeTask.java   |  51 ++++----
 .../apache/hugegraph/task/ServerInfoManager.java   |   6 +-
 .../hugegraph/task/StandardTaskScheduler.java      |  36 +++--
 .../org/apache/hugegraph/task/TaskCallable.java    |   6 +-
 .../org/apache/hugegraph/task/TaskManager.java     |  16 +--
 .../org/apache/hugegraph/task/TaskScheduler.java   |   8 +-
 .../java/org/apache/hugegraph/task/TaskStatus.java |   5 +-
 .../traversal/algorithm/CountTraverser.java        |   5 +-
 .../traversal/algorithm/HugeTraverser.java         |   1 +
 .../traversal/algorithm/NeighborRankTraverser.java |  11 +-
 .../traversal/algorithm/OltpTraverser.java         |   6 +-
 .../traversal/algorithm/PersonalRankTraverser.java |   5 +-
 .../traversal/algorithm/PredictionTraverser.java   |   1 +
 .../traversal/algorithm/ShortestPathTraverser.java |   9 +-
 .../algorithm/records/AbstractRecords.java         |   4 +-
 .../records/DoubleWayMultiPathsRecords.java        |   4 +-
 .../traversal/algorithm/records/KoutRecords.java   |   2 +-
 .../algorithm/records/record/SyncRecord.java       |   2 +-
 .../traversal/algorithm/steps/EdgeStep.java        |   6 +-
 .../traversal/algorithm/steps/RepeatEdgeStep.java  |   1 +
 .../algorithm/steps/WeightedEdgeStep.java          |   1 +
 .../strategy/ConcurrentTraverseStrategy.java       |   2 +-
 .../algorithm/strategy/SingleTraverseStrategy.java |  10 +-
 .../algorithm/strategy/TraverseStrategy.java       |   4 +-
 .../traversal/optimize/HugeCountStep.java          |   8 +-
 .../traversal/optimize/HugeCountStepStrategy.java  |  20 +--
 .../traversal/optimize/HugeGraphStep.java          |   5 +-
 .../traversal/optimize/HugeGraphStepStrategy.java  |   8 +-
 .../traversal/optimize/HugePrimaryKeyStrategy.java |   4 +-
 .../traversal/optimize/HugeScriptTraversal.java    |   4 +-
 .../traversal/optimize/HugeVertexStep.java         |  24 ++--
 .../traversal/optimize/HugeVertexStepByBatch.java  |  11 +-
 .../traversal/optimize/HugeVertexStepStrategy.java |  14 +-
 .../hugegraph/traversal/optimize/QueryHolder.java  |   3 +-
 .../traversal/optimize/TraversalUtil.java          |  30 ++---
 .../java/org/apache/hugegraph/type/Nameable.java   |   1 +
 .../hugegraph/type/define/CollectionType.java      |   2 +-
 .../org/apache/hugegraph/type/define/DataType.java |  12 +-
 .../apache/hugegraph/type/define/Directions.java   |   8 +-
 .../apache/hugegraph/type/define/IndexType.java    |   2 +-
 .../apache/hugegraph/type/define/SerialEnum.java   |   1 +
 .../org/apache/hugegraph/util/CompressUtil.java    |  13 +-
 .../java/org/apache/hugegraph/util/ConfigUtil.java |  17 ++-
 .../java/org/apache/hugegraph/util/Consumers.java  |   2 +-
 .../util/FixedTimerWindowRateLimiter.java          |   2 +-
 .../util/FixedWatchWindowRateLimiter.java          |   4 +-
 .../java/org/apache/hugegraph/util/GZipUtil.java   |   1 -
 .../java/org/apache/hugegraph/util/JsonUtil.java   |  11 +-
 .../java/org/apache/hugegraph/util/KryoUtil.java   |   2 +-
 .../java/org/apache/hugegraph/util/LockUtil.java   |  20 +--
 .../org/apache/hugegraph/util/ParameterUtil.java   |   2 -
 .../org/apache/hugegraph/util/RateLimiter.java     |   3 +
 .../java/org/apache/hugegraph/util/Reflection.java |  26 ++--
 .../org/apache/hugegraph/util/StringEncoding.java  |   1 -
 .../util/collection/CollectionFactory.java         |  29 ++---
 .../apache/hugegraph/util/collection/IdSet.java    |   9 +-
 .../hugegraph/util/collection/Int2IntsMap.java     |   2 +-
 .../hugegraph/util/collection/IntIterator.java     |   4 +-
 .../apache/hugegraph/util/collection/IntMap.java   |  21 ++-
 .../util/collection/IntMapByDynamicHash.java       |  36 ++---
 .../apache/hugegraph/util/collection/IntSet.java   |  11 +-
 .../util/collection/ObjectIntMappingFactory.java   |  11 +-
 .../apache/hugegraph/variables/HugeVariables.java  |  15 +--
 247 files changed, 1551 insertions(+), 1536 deletions(-)

diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeFactory.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeFactory.java
index 8c2c09faa..a1d03cf0d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeFactory.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeFactory.java
@@ -145,7 +145,8 @@ public class HugeFactory {
 
     /**
      * Stop all the daemon threads
-     * @param timeout wait in seconds
+     *
+     * @param timeout         wait in seconds
      * @param ignoreException don't throw exception if true
      */
     public static void shutdown(long timeout, boolean ignoreException) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraph.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraph.java
index 4566bf2cb..ab460d495 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraph.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraph.java
@@ -249,7 +249,7 @@ public interface HugeGraph extends Graph {
     <K, V> V option(TypedOption<K, V> option);
 
     void registerRpcServices(RpcServiceConfig4Server serverConfig,
-                                    RpcServiceConfig4Client clientConfig);
+                             RpcServiceConfig4Client clientConfig);
 
     default List<String> mapPkId2Name(Collection<Id> ids) {
         List<String> names = new ArrayList<>(ids.size());
@@ -316,8 +316,8 @@ public interface HugeGraph extends Graph {
 
     static void registerTraversalStrategies(Class<?> clazz) {
         TraversalStrategies strategies = TraversalStrategies.GlobalCache
-                                                            .getStrategies(Graph.class)
-                                                            .clone();
+                .getStrategies(Graph.class)
+                .clone();
         strategies.addStrategies(HugeVertexStepStrategy.instance(),
                                  HugeGraphStepStrategy.instance(),
                                  HugeCountStepStrategy.instance(),
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraphParams.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraphParams.java
index d29448391..5556fdfa6 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraphParams.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/HugeGraphParams.java
@@ -17,21 +17,22 @@
 
 package org.apache.hugegraph;
 
+import org.apache.hugegraph.analyzer.Analyzer;
 import org.apache.hugegraph.backend.LocalCounter;
+import org.apache.hugegraph.backend.serializer.AbstractSerializer;
 import org.apache.hugegraph.backend.store.BackendFeatures;
 import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.backend.store.ram.RamTable;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.event.EventHub;
 import org.apache.hugegraph.job.EphemeralJob;
 import org.apache.hugegraph.task.ServerInfoManager;
 import org.apache.hugegraph.type.define.GraphMode;
 import org.apache.hugegraph.type.define.GraphReadMode;
-import org.apache.hugegraph.analyzer.Analyzer;
-import org.apache.hugegraph.backend.serializer.AbstractSerializer;
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.hugegraph.event.EventHub;
+
 import com.google.common.util.concurrent.RateLimiter;
 
 /**
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/StandardHugeGraph.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/StandardHugeGraph.java
index 142ca9892..4e9263a48 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/StandardHugeGraph.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/StandardHugeGraph.java
@@ -123,26 +123,26 @@ import com.google.common.util.concurrent.RateLimiter;
 public class StandardHugeGraph implements HugeGraph {
 
     public static final Class<?>[] PROTECT_CLASSES = {
-        StandardHugeGraph.class,
-        StandardHugeGraph.StandardHugeGraphParams.class,
-        TinkerPopTransaction.class,
-        StandardHugeGraph.Txs.class,
-        StandardHugeGraph.SysTransaction.class
+            StandardHugeGraph.class,
+            StandardHugeGraph.StandardHugeGraphParams.class,
+            TinkerPopTransaction.class,
+            StandardHugeGraph.Txs.class,
+            StandardHugeGraph.SysTransaction.class
     };
 
     public static final Set<TypedOption<?, ?>> ALLOWED_CONFIGS = ImmutableSet.of(
-           CoreOptions.TASK_WAIT_TIMEOUT,
-           CoreOptions.TASK_SYNC_DELETION,
-           CoreOptions.TASK_TTL_DELETE_BATCH,
-           CoreOptions.TASK_INPUT_SIZE_LIMIT,
-           CoreOptions.TASK_RESULT_SIZE_LIMIT,
-           CoreOptions.OLTP_CONCURRENT_THREADS,
-           CoreOptions.OLTP_CONCURRENT_DEPTH,
-           CoreOptions.OLTP_COLLECTION_TYPE,
-           CoreOptions.VERTEX_DEFAULT_LABEL,
-           CoreOptions.VERTEX_ENCODE_PK_NUMBER,
-           CoreOptions.STORE_GRAPH,
-           CoreOptions.STORE
+            CoreOptions.TASK_WAIT_TIMEOUT,
+            CoreOptions.TASK_SYNC_DELETION,
+            CoreOptions.TASK_TTL_DELETE_BATCH,
+            CoreOptions.TASK_INPUT_SIZE_LIMIT,
+            CoreOptions.TASK_RESULT_SIZE_LIMIT,
+            CoreOptions.OLTP_CONCURRENT_THREADS,
+            CoreOptions.OLTP_CONCURRENT_DEPTH,
+            CoreOptions.OLTP_COLLECTION_TYPE,
+            CoreOptions.VERTEX_DEFAULT_LABEL,
+            CoreOptions.VERTEX_ENCODE_PK_NUMBER,
+            CoreOptions.STORE_GRAPH,
+            CoreOptions.STORE
     );
 
     private static final Logger LOG = Log.logger(StandardHugeGraph.class);
@@ -306,14 +306,17 @@ public class StandardHugeGraph implements HugeGraph {
     private void initRoleStateMachine(Id serverId) {
         HugeConfig conf = this.configuration;
         Config roleConfig = new RoleElectionConfig(serverId.toString(),
-                            conf.get(RoleElectionOptions.NODE_EXTERNAL_URL),
-                            conf.get(RoleElectionOptions.EXCEEDS_FAIL_COUNT),
-                            conf.get(RoleElectionOptions.RANDOM_TIMEOUT_MILLISECOND),
-                            conf.get(RoleElectionOptions.HEARTBEAT_INTERVAL_SECOND),
-                            conf.get(RoleElectionOptions.MASTER_DEAD_TIMES),
-                            conf.get(RoleElectionOptions.BASE_TIMEOUT_MILLISECOND));
+                                                   conf.get(RoleElectionOptions.NODE_EXTERNAL_URL),
+                                                   conf.get(RoleElectionOptions.EXCEEDS_FAIL_COUNT),
+                                                   conf.get(
+                                                           RoleElectionOptions.RANDOM_TIMEOUT_MILLISECOND),
+                                                   conf.get(
+                                                           RoleElectionOptions.HEARTBEAT_INTERVAL_SECOND),
+                                                   conf.get(RoleElectionOptions.MASTER_DEAD_TIMES),
+                                                   conf.get(
+                                                           RoleElectionOptions.BASE_TIMEOUT_MILLISECOND));
         ClusterRoleStore roleStore = new StandardClusterRoleStore(this.params);
-        this.roleElectionStateMachine = new StandardRoleElectionStateMachine(roleConfig, 
+        this.roleElectionStateMachine = new StandardRoleElectionStateMachine(roleConfig,
                                                                              roleStore);
     }
 
@@ -596,7 +599,7 @@ public class StandardHugeGraph implements HugeGraph {
 
     @Override
     public <C extends GraphComputer> C compute(Class<C> clazz)
-                                               throws IllegalArgumentException {
+            throws IllegalArgumentException {
         throw Graph.Exceptions.graphComputerNotSupported();
     }
 
@@ -605,11 +608,12 @@ public class StandardHugeGraph implements HugeGraph {
         throw Graph.Exceptions.graphComputerNotSupported();
     }
 
-    @SuppressWarnings({ "unchecked", "rawtypes" })
+    @SuppressWarnings({"unchecked", "rawtypes"})
     @Override
     public <I extends Io> I io(final Io.Builder<I> builder) {
         return (I) builder.graph(this).onMapper(mapper ->
-            mapper.addRegistry(HugeGraphIoRegistry.instance())
+                                                        mapper.addRegistry(
+                                                                HugeGraphIoRegistry.instance())
         ).create();
     }
 
@@ -1159,12 +1163,12 @@ public class StandardHugeGraph implements HugeGraph {
         // The proxy is sometimes unavailable (issue #664)
         CacheNotifier proxy = clientConfig.serviceProxy(this.name, clazz1);
         serverConfig.addService(this.name, clazz1, new HugeGraphCacheNotifier(
-                                                   this.graphEventHub, proxy));
+                this.graphEventHub, proxy));
 
         Class<SchemaCacheNotifier> clazz2 = SchemaCacheNotifier.class;
         proxy = clientConfig.serviceProxy(this.name, clazz2);
         serverConfig.addService(this.name, clazz2, new HugeSchemaCacheNotifier(
-                                                   this.schemaEventHub, proxy));
+                this.schemaEventHub, proxy));
     }
 
     private void closeTx() {
@@ -1522,7 +1526,7 @@ public class StandardHugeGraph implements HugeGraph {
         private void destroyTransaction() {
             if (this.isOpen()) {
                 throw new HugeException(
-                          "Transaction should be closed before destroying");
+                        "Transaction should be closed before destroying");
             }
 
             // Do close if needed, then remove the reference
@@ -1663,8 +1667,8 @@ public class StandardHugeGraph implements HugeGraph {
     }
 
     private static class HugeSchemaCacheNotifier
-                   extends AbstractCacheNotifier
-                   implements SchemaCacheNotifier {
+            extends AbstractCacheNotifier
+            implements SchemaCacheNotifier {
 
         public HugeSchemaCacheNotifier(EventHub hub, CacheNotifier proxy) {
             super(hub, proxy);
@@ -1672,8 +1676,8 @@ public class StandardHugeGraph implements HugeGraph {
     }
 
     private static class HugeGraphCacheNotifier
-                   extends AbstractCacheNotifier
-                   implements GraphCacheNotifier {
+            extends AbstractCacheNotifier
+            implements GraphCacheNotifier {
 
         public HugeGraphCacheNotifier(EventHub hub, CacheNotifier proxy) {
             super(hub, proxy);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnalyzerFactory.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnalyzerFactory.java
index 463b96227..21dd157b1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnalyzerFactory.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnalyzerFactory.java
@@ -64,12 +64,12 @@ public class AnalyzerFactory {
             return clazz.getConstructor(String.class).newInstance(mode);
         } catch (Exception e) {
             throw new HugeException(
-                      "Failed to construct analyzer '%s' with mode '%s'",
-                      e, name, mode);
+                    "Failed to construct analyzer '%s' with mode '%s'",
+                    e, name, mode);
         }
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public static void register(String name, String classPath) {
         ClassLoader classLoader = SerializerFactory.class.getClassLoader();
         Class<?> clazz;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnsjAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnsjAnalyzer.java
index f32303518..2f857cd17 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnsjAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnsjAnalyzer.java
@@ -26,9 +26,9 @@ import org.ansj.splitWord.analysis.BaseAnalysis;
 import org.ansj.splitWord.analysis.IndexAnalysis;
 import org.ansj.splitWord.analysis.NlpAnalysis;
 import org.ansj.splitWord.analysis.ToAnalysis;
-
 import org.apache.hugegraph.config.ConfigException;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableList;
 
 /**
@@ -48,8 +48,8 @@ public class AnsjAnalyzer implements Analyzer {
     public AnsjAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for ansj analyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for ansj analyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
         this.analysis = mode;
     }
@@ -72,7 +72,7 @@ public class AnsjAnalyzer implements Analyzer {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported segment mode '%s'", this.analysis));
+                        "Unsupported segment mode '%s'", this.analysis));
         }
 
         assert terms != null;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/HanLPAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/HanLPAnalyzer.java
index baf6c6884..8b5fa6aa0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/HanLPAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/HanLPAnalyzer.java
@@ -22,6 +22,7 @@ import java.util.Set;
 
 import org.apache.hugegraph.config.ConfigException;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableList;
 import com.hankcs.hanlp.seg.Dijkstra.DijkstraSegment;
 import com.hankcs.hanlp.seg.NShort.NShortSegment;
@@ -38,14 +39,14 @@ import com.hankcs.hanlp.tokenizer.StandardTokenizer;
 public class HanLPAnalyzer implements Analyzer {
 
     public static final List<String> SUPPORT_MODES =
-           ImmutableList.<String>builder()
-                        .add("standard")
-                        .add("nlp")
-                        .add("index")
-                        .add("nShort")
-                        .add("shortest")
-                        .add("speed")
-                        .build();
+            ImmutableList.<String>builder()
+                         .add("standard")
+                         .add("nlp")
+                         .add("index")
+                         .add("nShort")
+                         .add("shortest")
+                         .add("speed")
+                         .build();
 
     private static final Segment N_SHORT_SEGMENT =
             new NShortSegment().enableCustomDictionary(false)
@@ -61,8 +62,8 @@ public class HanLPAnalyzer implements Analyzer {
     public HanLPAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for hanlp analyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for hanlp analyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
         this.tokenizer = mode;
     }
@@ -91,7 +92,7 @@ public class HanLPAnalyzer implements Analyzer {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported segment mode '%s'", this.tokenizer));
+                        "Unsupported segment mode '%s'", this.tokenizer));
         }
 
         assert terms != null;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/IKAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/IKAnalyzer.java
index 2c25c2f41..ab564f396 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/IKAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/IKAnalyzer.java
@@ -22,11 +22,11 @@ import java.util.List;
 import java.util.Set;
 
 import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.config.ConfigException;
+import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.wltea.analyzer.core.IKSegmenter;
 import org.wltea.analyzer.core.Lexeme;
 
-import org.apache.hugegraph.config.ConfigException;
-import org.apache.hugegraph.util.InsertionOrderUtil;
 import com.google.common.collect.ImmutableList;
 
 /**
@@ -44,8 +44,8 @@ public class IKAnalyzer implements Analyzer {
     public IKAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for ikanalyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for ikanalyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
         this.smartSegMode = SUPPORT_MODES.get(0).equals(mode);
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JcsegAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JcsegAnalyzer.java
index ad00ea476..3740e87b1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JcsegAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JcsegAnalyzer.java
@@ -22,14 +22,14 @@ import java.util.List;
 import java.util.Set;
 
 import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.config.ConfigException;
+import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.lionsoul.jcseg.ISegment;
 import org.lionsoul.jcseg.IWord;
 import org.lionsoul.jcseg.dic.ADictionary;
 import org.lionsoul.jcseg.dic.DictionaryFactory;
 import org.lionsoul.jcseg.segmenter.SegmenterConfig;
 
-import org.apache.hugegraph.config.ConfigException;
-import org.apache.hugegraph.util.InsertionOrderUtil;
 import com.google.common.collect.ImmutableList;
 
 /**
@@ -50,8 +50,8 @@ public class JcsegAnalyzer implements Analyzer {
     public JcsegAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for jcseg analyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for jcseg analyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
 
         if ("Simple".equals(mode)) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JiebaAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JiebaAnalyzer.java
index b79973c9b..7c280a50a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JiebaAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/JiebaAnalyzer.java
@@ -22,6 +22,7 @@ import java.util.Set;
 
 import org.apache.hugegraph.config.ConfigException;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableList;
 import com.huaban.analysis.jieba.JiebaSegmenter;
 import com.huaban.analysis.jieba.SegToken;
@@ -43,8 +44,8 @@ public class JiebaAnalyzer implements Analyzer {
     public JiebaAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for jieba analyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for jieba analyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
         this.segMode = JiebaSegmenter.SegMode.valueOf(mode);
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/MMSeg4JAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/MMSeg4JAnalyzer.java
index 62264014b..26e937a53 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/MMSeg4JAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/MMSeg4JAnalyzer.java
@@ -24,6 +24,7 @@ import java.util.Set;
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.config.ConfigException;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.chenlb.mmseg4j.ComplexSeg;
 import com.chenlb.mmseg4j.Dictionary;
 import com.chenlb.mmseg4j.MMSeg;
@@ -51,8 +52,8 @@ public class MMSeg4JAnalyzer implements Analyzer {
     public MMSeg4JAnalyzer(String mode) {
         if (!SUPPORT_MODES.contains(mode)) {
             throw new ConfigException(
-                      "Unsupported segment mode '%s' for mmseg4j analyzer, " +
-                      "the available values are %s", mode, SUPPORT_MODES);
+                    "Unsupported segment mode '%s' for mmseg4j analyzer, " +
+                    "the available values are %s", mode, SUPPORT_MODES);
         }
         int index = SUPPORT_MODES.indexOf(mode);
         switch (index) {
@@ -67,7 +68,7 @@ public class MMSeg4JAnalyzer implements Analyzer {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported segment mode '%s'", mode));
+                        "Unsupported segment mode '%s'", mode));
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/SmartCNAnalyzer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/SmartCNAnalyzer.java
index 0776c8a79..f265ade21 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/SmartCNAnalyzer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/SmartCNAnalyzer.java
@@ -22,19 +22,18 @@ import java.io.StringReader;
 import java.util.Set;
 
 import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.cn.smart.SmartChineseAnalyzer;
 import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
 
-import org.apache.hugegraph.util.InsertionOrderUtil;
-
 /**
  * Reference from https://lucene.apache.org/core/8_11_2/analyzers-smartcn/index.html
  */
 public class SmartCNAnalyzer implements Analyzer {
 
     private static final SmartChineseAnalyzer ANALYZER =
-                                              new SmartChineseAnalyzer();
+            new SmartChineseAnalyzer();
 
     public SmartCNAnalyzer(String mode) {
         // pass
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/AuthManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/AuthManager.java
index 3236c2fe7..51c72fba4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/AuthManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/AuthManager.java
@@ -22,8 +22,8 @@ import java.util.Set;
 
 import javax.security.sasl.AuthenticationException;
 
-import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.auth.SchemaDefine.AuthElement;
+import org.apache.hugegraph.backend.id.Id;
 
 public interface AuthManager {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/EntityManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/EntityManager.java
index e6beffda4..463362572 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/EntityManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/EntityManager.java
@@ -22,26 +22,26 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Entity;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.iterator.MapperIterator;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.HugeKeys;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Entity;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.iterator.MapperIterator;
-import org.apache.hugegraph.structure.HugeVertex;
-import org.apache.hugegraph.util.E;
 import com.google.common.collect.ImmutableMap;
 
 public class EntityManager<T extends Entity> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeAccess.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeAccess.java
index 015b875ce..85ac82bc1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeAccess.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeAccess.java
@@ -22,17 +22,16 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Relationship;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.type.define.DataType;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Relationship;
-import org.apache.hugegraph.util.E;
-
 public class HugeAccess extends Relationship {
 
     private static final long serialVersionUID = -7644007602408729385L;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeBelong.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeBelong.java
index de197f9e3..ce23f8801 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeBelong.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeBelong.java
@@ -22,15 +22,14 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Relationship;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Relationship;
-
 public class HugeBelong extends Relationship {
 
     public static final String UG = "ug";
@@ -103,12 +102,10 @@ public class HugeBelong extends Relationship {
         if (super.property(key, value)) {
             return true;
         }
-        switch (key) {
-            case P.DESCRIPTION:
-                this.description = (String) value;
-                break;
-            default:
-                throw new AssertionError("Unsupported key: " + key);
+        if (key.equals(P.DESCRIPTION)) {
+            this.description = (String) value;
+        } else {
+            throw new AssertionError("Unsupported key: " + key);
         }
         return true;
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeGroup.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeGroup.java
index 6b9fd3d89..ee2470076 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeGroup.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeGroup.java
@@ -22,16 +22,15 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Entity;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Entity;
-import org.apache.hugegraph.util.E;
-
 public class HugeGroup extends Entity {
 
     private static final long serialVersionUID = 2330399818352242686L;
@@ -195,7 +194,7 @@ public class HugeGroup extends Entity {
             this.graph.schemaTransaction().addVertexLabel(label);
         }
 
-        protected String[] initProperties() {
+        private String[] initProperties() {
             List<String> props = new ArrayList<>();
 
             props.add(createPropertyKey(P.NAME));
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeProject.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeProject.java
index 7283a3133..f630ba6bc 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeProject.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeProject.java
@@ -25,19 +25,18 @@ import java.util.Map;
 import java.util.Set;
 
 import org.apache.commons.lang.StringUtils;
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Entity;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Graph;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Entity;
-import org.apache.hugegraph.util.E;
-
 public class HugeProject extends Entity {
 
     private static final long serialVersionUID = 8681323499069874520L;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeResource.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeResource.java
index 3911a5845..9edaac5c6 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeResource.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeResource.java
@@ -23,6 +23,10 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.auth.SchemaDefine.AuthElement;
+import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.traversal.optimize.TraversalUtil;
 import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.type.Typeable;
 import org.apache.hugegraph.util.JsonUtil;
@@ -39,10 +43,6 @@ import org.apache.tinkerpop.shaded.jackson.databind.deser.std.StdDeserializer;
 import org.apache.tinkerpop.shaded.jackson.databind.module.SimpleModule;
 import org.apache.tinkerpop.shaded.jackson.databind.ser.std.StdSerializer;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.auth.SchemaDefine.AuthElement;
-import org.apache.hugegraph.structure.HugeElement;
-import org.apache.hugegraph.traversal.optimize.TraversalUtil;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -55,7 +55,7 @@ public class HugeResource {
     public static final List<HugeResource> ALL_RES = ImmutableList.of(ALL);
 
     private static final Set<ResourceType> CHECK_NAME_RESS = ImmutableSet.of(
-                                                             ResourceType.META);
+            ResourceType.META);
 
     static {
         SimpleModule module = new SimpleModule();
@@ -143,7 +143,7 @@ public class HugeResource {
 
     private boolean filter(Nameable element) {
         assert !(element instanceof Typeable) || this.type.match(
-               ResourceType.from(((Typeable) element).type()));
+                ResourceType.from(((Typeable) element).type()));
 
         return this.matchLabel(element.name());
     }
@@ -258,7 +258,8 @@ public class HugeResource {
     }
 
     public static List<HugeResource> parseResources(String resources) {
-        TypeReference<?> type = new TypeReference<List<HugeResource>>() {};
+        TypeReference<?> type = new TypeReference<List<HugeResource>>() {
+        };
         return JsonUtil.fromJson(resources, type);
     }
 
@@ -298,7 +299,7 @@ public class HugeResource {
         @Override
         public void serialize(HugeResource res, JsonGenerator generator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             generator.writeStartObject();
 
             generator.writeObjectField("type", res.type);
@@ -320,7 +321,7 @@ public class HugeResource {
         @Override
         public HugeResource deserialize(JsonParser parser,
                                         DeserializationContext ctxt)
-                                        throws IOException {
+                throws IOException {
             HugeResource res = new HugeResource();
             while (parser.nextToken() != JsonToken.END_OBJECT) {
                 String key = parser.getCurrentName();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeTarget.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeTarget.java
index 5687fdab8..56f59c27b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeTarget.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeTarget.java
@@ -22,18 +22,17 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Entity;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Entity;
-import org.apache.hugegraph.util.E;
-
 import com.google.common.collect.ImmutableList;
 
 public class HugeTarget extends Entity {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeUser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeUser.java
index 9df3d0cb3..1fc087a70 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeUser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/HugeUser.java
@@ -22,16 +22,15 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Entity;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Entity;
-import org.apache.hugegraph.util.E;
-
 public class HugeUser extends Entity {
 
     private static final long serialVersionUID = -8951193710873772717L;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RelationshipManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RelationshipManager.java
index 2fe226027..a1c440611 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RelationshipManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RelationshipManager.java
@@ -22,29 +22,29 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.auth.SchemaDefine.Relationship;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.iterator.MapperIterator;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.structure.HugeEdge;
+import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.type.define.HugeKeys;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.auth.SchemaDefine.Relationship;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.iterator.MapperIterator;
-import org.apache.hugegraph.structure.HugeEdge;
-import org.apache.hugegraph.structure.HugeVertex;
-import org.apache.hugegraph.util.E;
 import com.google.common.collect.ImmutableMap;
 
 public class RelationshipManager<T extends Relationship> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceObject.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceObject.java
index 40e5c0ec9..03234f597 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceObject.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceObject.java
@@ -19,8 +19,8 @@ package org.apache.hugegraph.auth;
 
 import org.apache.hugegraph.auth.SchemaDefine.AuthElement;
 import org.apache.hugegraph.schema.SchemaElement;
-import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.util.E;
 
 public class ResourceObject<V> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceType.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceType.java
index c5ab9b96d..caeafc8d0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceType.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/ResourceType.java
@@ -17,6 +17,8 @@
 
 package org.apache.hugegraph.auth;
 
+import java.util.Objects;
+
 import org.apache.hugegraph.type.HugeType;
 
 public enum ResourceType {
@@ -70,11 +72,8 @@ public enum ResourceType {
             return true;
         }
 
-        switch (required) {
-            case NONE:
-                return this != NONE;
-            default:
-                break;
+        if (Objects.requireNonNull(required) == ResourceType.NONE) {
+            return this != NONE;
         }
 
         switch (this) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RolePermission.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RolePermission.java
index 033ffa22b..b7d776d6f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RolePermission.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/RolePermission.java
@@ -25,6 +25,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.TreeMap;
 
+import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.tinkerpop.shaded.jackson.annotation.JsonProperty;
 import org.apache.tinkerpop.shaded.jackson.core.JsonGenerator;
@@ -37,14 +38,12 @@ import org.apache.tinkerpop.shaded.jackson.databind.deser.std.StdDeserializer;
 import org.apache.tinkerpop.shaded.jackson.databind.module.SimpleModule;
 import org.apache.tinkerpop.shaded.jackson.databind.ser.std.StdSerializer;
 
-import org.apache.hugegraph.util.E;
-
 public class RolePermission {
 
     public static final RolePermission NONE = RolePermission.role(
-                                              "none", HugePermission.NONE);
+            "none", HugePermission.NONE);
     public static final RolePermission ADMIN = RolePermission.role(
-                                               "admin", HugePermission.ANY);
+            "admin", HugePermission.ANY);
 
     static {
         SimpleModule module = new SimpleModule();
@@ -64,7 +63,7 @@ public class RolePermission {
     }
 
     private RolePermission(Map<String, Map<HugePermission,
-                                       List<HugeResource>>> roles) {
+            List<HugeResource>>> roles) {
         this.roles = roles;
     }
 
@@ -76,7 +75,7 @@ public class RolePermission {
     protected void add(String graph, HugePermission action,
                        List<HugeResource> resources) {
         Map<HugePermission, List<HugeResource>> permissions =
-                                                this.roles.get(graph);
+                this.roles.get(graph);
         if (permissions == null) {
             permissions = new TreeMap<>();
             this.roles.put(graph, permissions);
@@ -95,14 +94,14 @@ public class RolePermission {
 
     public boolean contains(RolePermission other) {
         for (Map.Entry<String, Map<HugePermission, List<HugeResource>>> e1 :
-             other.roles.entrySet()) {
+                other.roles.entrySet()) {
             String g = e1.getKey();
             Map<HugePermission, List<HugeResource>> perms = this.roles.get(g);
             if (perms == null) {
                 return false;
             }
             for (Map.Entry<HugePermission, List<HugeResource>> e2 :
-                e1.getValue().entrySet()) {
+                    e1.getValue().entrySet()) {
                 List<HugeResource> ress = perms.get(e2.getKey());
                 if (ress == null) {
                     return false;
@@ -189,7 +188,7 @@ public class RolePermission {
     }
 
     private static class RolePermissionSer
-                   extends StdSerializer<RolePermission> {
+            extends StdSerializer<RolePermission> {
 
         private static final long serialVersionUID = -2533310506459479383L;
 
@@ -200,7 +199,7 @@ public class RolePermission {
         @Override
         public void serialize(RolePermission role, JsonGenerator generator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             generator.writeStartObject();
             generator.writeObjectField("roles", role.roles);
             generator.writeEndObject();
@@ -208,7 +207,7 @@ public class RolePermission {
     }
 
     private static class RolePermissionDeser
-                   extends StdDeserializer<RolePermission> {
+            extends StdDeserializer<RolePermission> {
 
         private static final long serialVersionUID = -2038234657843260957L;
 
@@ -219,9 +218,10 @@ public class RolePermission {
         @Override
         public RolePermission deserialize(JsonParser parser,
                                           DeserializationContext ctxt)
-                                          throws IOException {
+                throws IOException {
             TypeReference<?> type = new TypeReference<TreeMap<String,
-                             TreeMap<HugePermission, List<HugeResource>>>>() {};
+                    TreeMap<HugePermission, List<HugeResource>>>>() {
+            };
             if ("roles".equals(parser.nextFieldName())) {
                 parser.nextValue();
                 return new RolePermission(parser.readValueAs(type));
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/SchemaDefine.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/SchemaDefine.java
index 5ad5c824f..faec762a0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/SchemaDefine.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/SchemaDefine.java
@@ -23,6 +23,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.auth.HugeTarget.P;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -31,18 +32,15 @@ import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.VertexProperty;
 
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.util.E;
-
 public abstract class SchemaDefine {
 
     protected final HugeGraphParams graph;
@@ -242,7 +240,7 @@ public abstract class SchemaDefine {
 
     // NOTE: travis-ci fails if class Entity implements Nameable
     public abstract static class Entity extends AuthElement
-                           implements org.apache.hugegraph.type.Nameable {
+            implements org.apache.hugegraph.type.Nameable {
 
         private static final long serialVersionUID = 4113319546914811762L;
 
@@ -260,7 +258,7 @@ public abstract class SchemaDefine {
                             vertex.label(), entity.label());
             entity.id((Id) vertex.id());
             for (Iterator<VertexProperty<Object>> iter = vertex.properties();
-                 iter.hasNext();) {
+                 iter.hasNext(); ) {
                 VertexProperty<Object> prop = iter.next();
                 entity.property(prop.key(), prop.value());
             }
@@ -310,7 +308,7 @@ public abstract class SchemaDefine {
                             edge.label(), relationship.label());
             relationship.id((Id) edge.id());
             for (Iterator<Property<Object>> iter = edge.properties();
-                 iter.hasNext();) {
+                 iter.hasNext(); ) {
                 Property<Object> prop = iter.next();
                 relationship.property(prop.key(), prop.value());
             }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/StandardAuthManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/StandardAuthManager.java
index d79840380..60aaf9aab 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/StandardAuthManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/StandardAuthManager.java
@@ -411,13 +411,13 @@ public class StandardAuthManager implements AuthManager {
             Id adminGroupId = project.adminGroupId();
             Id opGroupId = project.opGroupId();
             HugeAccess adminGroupWriteAccess = new HugeAccess(
-                                                   adminGroupId, targetId,
-                                                   HugePermission.WRITE);
+                    adminGroupId, targetId,
+                    HugePermission.WRITE);
             // Ditto
             adminGroupWriteAccess.creator(project.creator());
             HugeAccess adminGroupReadAccess = new HugeAccess(
-                                                  adminGroupId, targetId,
-                                                  HugePermission.READ);
+                    adminGroupId, targetId,
+                    HugePermission.READ);
             // Ditto
             adminGroupReadAccess.creator(project.creator());
             HugeAccess opGroupReadAccess = new HugeAccess(opGroupId, targetId,
@@ -634,7 +634,7 @@ public class StandardAuthManager implements AuthManager {
 
     @Override
     public String loginUser(String username, String password)
-                            throws AuthenticationException {
+            throws AuthenticationException {
         HugeUser user = this.matchUser(username, password);
         if (user == null) {
             String msg = "Incorrect username or password";
@@ -672,10 +672,10 @@ public class StandardAuthManager implements AuthManager {
         Claims payload = null;
         boolean needBuildCache = false;
         if (username == null) {
-            try{
+            try {
                 payload = this.tokenGenerator.verify(token);
-            }catch (Throwable t){
-                LOG.error(String.format("Failed to verify token:[ %s ], cause:",token),t);
+            } catch (Throwable t) {
+                LOG.error(String.format("Failed to verify token:[ %s ], cause:", token), t);
                 return new UserWithRole("");
             }
             username = (String) payload.get(AuthConstant.TOKEN_USER_NAME);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/TokenGenerator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/TokenGenerator.java
index e8ee77e8f..0814e84b1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/TokenGenerator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/TokenGenerator.java
@@ -22,7 +22,6 @@ import java.util.Date;
 import java.util.Map;
 
 import javax.crypto.SecretKey;
-import jakarta.ws.rs.NotAuthorizedException;
 
 import org.apache.hugegraph.config.AuthOptions;
 import org.apache.hugegraph.config.HugeConfig;
@@ -34,6 +33,7 @@ import io.jsonwebtoken.JwtException;
 import io.jsonwebtoken.Jwts;
 import io.jsonwebtoken.SignatureAlgorithm;
 import io.jsonwebtoken.security.Keys;
+import jakarta.ws.rs.NotAuthorizedException;
 
 public class TokenGenerator {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/BackendException.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/BackendException.java
index 95f271b79..a1f587866 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/BackendException.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/BackendException.java
@@ -44,7 +44,7 @@ public class BackendException extends HugeException {
     }
 
     public static final void check(boolean expression, String message, Object... args)
-                                   throws BackendException {
+            throws BackendException {
         if (!expression) {
             throw new BackendException(message, args);
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/AbstractCache.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/AbstractCache.java
index dff48f509..e26a779f4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/AbstractCache.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/AbstractCache.java
@@ -22,10 +22,9 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.atomic.LongAdder;
 import java.util.function.Function;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class AbstractCache<K, V> implements Cache<K, V> {
 
@@ -183,7 +182,7 @@ public abstract class AbstractCache<K, V> implements Cache<K, V> {
 
         int expireItems = 0;
         long current = now();
-        for (Iterator<CacheNode<K, V>> it = this.nodes(); it.hasNext();) {
+        for (Iterator<CacheNode<K, V>> it = this.nodes(); it.hasNext(); ) {
             CacheNode<K, V> node = it.next();
             if (current - node.time() >= expireTime) {
                 // Remove item while iterating map (it must be ConcurrentMap)
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
index 8e7742ef8..c7a43e228 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
@@ -24,12 +24,11 @@ import java.util.Timer;
 import java.util.TimerTask;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class CacheManager {
 
@@ -69,7 +68,7 @@ public class CacheManager {
             public void run() {
                 try {
                     for (Entry<String, Cache<Id, Object>> entry :
-                         caches().entrySet()) {
+                            caches().entrySet()) {
                         this.tick(entry.getKey(), entry.getValue());
                     }
                 } catch (Throwable e) {
@@ -97,7 +96,7 @@ public class CacheManager {
     }
 
     public <V> Map<String, Cache<Id, V>> caches() {
-        @SuppressWarnings({ "rawtypes", "unchecked" })
+        @SuppressWarnings({"rawtypes", "unchecked"})
         Map<String, Cache<Id, V>> caches = (Map) this.caches;
         return Collections.unmodifiableMap(caches);
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheNotifier.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheNotifier.java
index a6ecebb11..e470f1067 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheNotifier.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheNotifier.java
@@ -30,7 +30,11 @@ public interface CacheNotifier extends AutoCloseable {
 
     void reload();
 
-    interface GraphCacheNotifier extends CacheNotifier {}
+    interface GraphCacheNotifier extends CacheNotifier {
 
-    interface SchemaCacheNotifier extends CacheNotifier {}
+    }
+
+    interface SchemaCacheNotifier extends CacheNotifier {
+
+    }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedBackendStore.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedBackendStore.java
index a6a2bdc71..a1c632d9f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedBackendStore.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedBackendStore.java
@@ -19,8 +19,8 @@ package org.apache.hugegraph.backend.cache;
 
 import java.util.Iterator;
 
-import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.BackendFeatures;
 import org.apache.hugegraph.backend.store.BackendMutation;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedGraphTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedGraphTransaction.java
index bb14444d9..89f047bae 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedGraphTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedGraphTransaction.java
@@ -25,15 +25,15 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.cache.CachedBackendStore.QueryId;
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.store.BackendMutation;
 import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.backend.store.ram.RamTable;
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.backend.query.IdQuery;
-import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
@@ -49,6 +49,7 @@ import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Events;
+
 import com.google.common.collect.ImmutableSet;
 
 public final class CachedGraphTransaction extends GraphTransaction {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedSchemaTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedSchemaTransaction.java
index 69c09aabf..4f9e5f593 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedSchemaTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CachedSchemaTransaction.java
@@ -23,12 +23,12 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Consumer;
 
-import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.backend.store.ram.IntObjectMap;
-import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.backend.store.BackendStore;
+import org.apache.hugegraph.backend.store.ram.IntObjectMap;
+import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.event.EventHub;
 import org.apache.hugegraph.event.EventListener;
@@ -37,6 +37,7 @@ import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Events;
+
 import com.google.common.collect.ImmutableSet;
 
 public final class CachedSchemaTransaction extends SchemaTransaction {
@@ -437,7 +438,7 @@ public final class CachedSchemaTransaction extends SchemaTransaction {
     }
 
     private static class CachedTypes
-                   extends ConcurrentHashMap<HugeType, Boolean> {
+            extends ConcurrentHashMap<HugeType, Boolean> {
 
         private static final long serialVersionUID = -2215549791679355996L;
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/OffheapCache.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/OffheapCache.java
index a97898f2b..d641c8276 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/OffheapCache.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/OffheapCache.java
@@ -24,14 +24,6 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.function.Consumer;
 
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
-import org.caffinitas.ohc.CacheSerializer;
-import org.caffinitas.ohc.CloseableIterator;
-import org.caffinitas.ohc.Eviction;
-import org.caffinitas.ohc.OHCache;
-import org.caffinitas.ohc.OHCacheBuilder;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
@@ -39,6 +31,8 @@ import org.apache.hugegraph.backend.serializer.AbstractSerializer;
 import org.apache.hugegraph.backend.serializer.BinaryBackendEntry;
 import org.apache.hugegraph.backend.serializer.BinarySerializer;
 import org.apache.hugegraph.backend.serializer.BytesBuffer;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.HugeType;
@@ -46,6 +40,11 @@ import org.apache.hugegraph.type.define.DataType;
 import org.apache.hugegraph.util.Bytes;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+import org.caffinitas.ohc.CacheSerializer;
+import org.caffinitas.ohc.CloseableIterator;
+import org.caffinitas.ohc.Eviction;
+import org.caffinitas.ohc.OHCache;
+import org.caffinitas.ohc.OHCacheBuilder;
 
 public class OffheapCache extends AbstractCache<Id, Object> {
 
@@ -119,7 +118,7 @@ public class OffheapCache extends AbstractCache<Id, Object> {
         }
         if (serializedSize > VALUE_SIZE_TO_SKIP) {
             LOG.info("Skip to cache '{}' due to value size {} > limit {}",
-                      id, serializedSize, VALUE_SIZE_TO_SKIP);
+                     id, serializedSize, VALUE_SIZE_TO_SKIP);
             return false;
         }
 
@@ -334,13 +333,13 @@ public class OffheapCache extends AbstractCache<Id, Object> {
 
         private HugeException unsupported(ValueType type) {
             throw new HugeException(
-                      "Unsupported deserialize type: %s", type);
+                    "Unsupported deserialize type: %s", type);
         }
 
         private HugeException unsupported(Object value) {
             throw new HugeException(
-                      "Unsupported type of serialize value: '%s'(%s)",
-                      value, value.getClass());
+                    "Unsupported type of serialize value: '%s'(%s)",
+                    value, value.getClass());
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/RamCache.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/RamCache.java
index 05366f9af..a5e8d162a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/RamCache.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/RamCache.java
@@ -156,7 +156,7 @@ public class RamCache extends AbstractCache<Id, Object> {
     @Override
     protected Iterator<CacheNode<Id, Object>> nodes() {
         Iterator<LinkNode<Id, Object>> iter = this.map.values().iterator();
-        @SuppressWarnings({ "unchecked", "rawtypes" })
+        @SuppressWarnings({"unchecked", "rawtypes"})
         Iterator<CacheNode<Id, Object>> iterSuper = (Iterator) iter;
         return iterSuper;
     }
@@ -280,8 +280,8 @@ public class RamCache extends AbstractCache<Id, Object> {
         /**
          * Reset the head node and rear node
          * NOTE:
-         *  only called by LinkedQueueNonBigLock() without lock
-         *  or called by clear() with lock(head, rear)
+         * only called by LinkedQueueNonBigLock() without lock
+         * or called by clear() with lock(head, rear)
          */
         private void reset() {
             this.head.prev = this.empty;
@@ -316,7 +316,7 @@ public class RamCache extends AbstractCache<Id, Object> {
             List<K> keys = this.dumpKeys();
             if (keys.contains(key)) {
                 throw new RuntimeException(String.format(
-                          "Expect %s should be not in %s", key, keys));
+                        "Expect %s should be not in %s", key, keys));
             }
             return true;
         }
@@ -338,8 +338,8 @@ public class RamCache extends AbstractCache<Id, Object> {
             int selfPos = keys.indexOf(self.key());
             if (prevPos > selfPos && selfPos != -1) {
                 throw new RuntimeException(String.format(
-                          "Expect %s should be before %s, actual %s",
-                          prev.key(), self.key(), keys));
+                        "Expect %s should be before %s, actual %s",
+                        prev.key(), self.key(), keys));
             }
             return true;
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/EdgeId.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/EdgeId.java
index 711ee0d87..a9053e513 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/EdgeId.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/EdgeId.java
@@ -35,12 +35,12 @@ import org.apache.hugegraph.util.StringEncoding;
  */
 public class EdgeId implements Id {
 
-    public static final HugeKeys[] KEYS = new HugeKeys[] {
-        HugeKeys.OWNER_VERTEX,
-        HugeKeys.DIRECTION,
-        HugeKeys.LABEL,
-        HugeKeys.SORT_VALUES,
-        HugeKeys.OTHER_VERTEX
+    public static final HugeKeys[] KEYS = new HugeKeys[]{
+            HugeKeys.OWNER_VERTEX,
+            HugeKeys.DIRECTION,
+            HugeKeys.LABEL,
+            HugeKeys.SORT_VALUES,
+            HugeKeys.OTHER_VERTEX
     };
 
     private final Id ownerVertexId;
@@ -135,17 +135,17 @@ public class EdgeId implements Id {
         }
         if (this.directed) {
             this.cache = SplicingIdGenerator.concat(
-                         IdUtil.writeString(this.ownerVertexId),
-                         this.direction.type().string(),
-                         IdUtil.writeLong(this.edgeLabelId),
-                         this.sortValues,
-                         IdUtil.writeString(this.otherVertexId));
+                    IdUtil.writeString(this.ownerVertexId),
+                    this.direction.type().string(),
+                    IdUtil.writeLong(this.edgeLabelId),
+                    this.sortValues,
+                    IdUtil.writeString(this.otherVertexId));
         } else {
             this.cache = SplicingIdGenerator.concat(
-                         IdUtil.writeString(this.sourceVertexId()),
-                         IdUtil.writeLong(this.edgeLabelId),
-                         this.sortValues,
-                         IdUtil.writeString(this.targetVertexId()));
+                    IdUtil.writeString(this.sourceVertexId()),
+                    IdUtil.writeLong(this.edgeLabelId),
+                    this.sortValues,
+                    IdUtil.writeString(this.targetVertexId()));
         }
         return this.cache;
     }
@@ -233,7 +233,7 @@ public class EdgeId implements Id {
     }
 
     public static EdgeId parse(String id, boolean returnNullIfError)
-                               throws NotFoundException {
+            throws NotFoundException {
         String[] idParts = SplicingIdGenerator.split(id);
         if (!(idParts.length == 4 || idParts.length == 5)) {
             if (returnNullIfError) {
@@ -284,10 +284,10 @@ public class EdgeId implements Id {
     public static String asStoredString(Id id) {
         EdgeId eid = (EdgeId) id;
         return SplicingIdGenerator.concat(
-               IdUtil.writeStoredString(eid.sourceVertexId()),
-               IdGenerator.asStoredString(eid.edgeLabelId()),
-               eid.sortValues(),
-               IdUtil.writeStoredString(eid.targetVertexId()));
+                IdUtil.writeStoredString(eid.sourceVertexId()),
+                IdGenerator.asStoredString(eid.edgeLabelId()),
+                eid.sortValues(),
+                IdUtil.writeStoredString(eid.targetVertexId()));
     }
 
     public static String concat(String... ids) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/IdUtil.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/IdUtil.java
index 11d9378f0..90cd98d4b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/IdUtil.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/IdUtil.java
@@ -20,7 +20,6 @@ package org.apache.hugegraph.backend.id;
 import java.nio.ByteBuffer;
 
 import org.apache.commons.lang3.StringUtils;
-
 import org.apache.hugegraph.backend.id.Id.IdType;
 import org.apache.hugegraph.backend.serializer.BytesBuffer;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SnowflakeIdGenerator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SnowflakeIdGenerator.java
index 0ac86353f..21059e529 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SnowflakeIdGenerator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SnowflakeIdGenerator.java
@@ -16,8 +16,6 @@ package org.apache.hugegraph.backend.id;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
@@ -27,13 +25,14 @@ import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.TimeUtil;
+import org.slf4j.Logger;
 
 public class SnowflakeIdGenerator extends IdGenerator {
 
     private static final Logger LOG = Log.logger(SnowflakeIdGenerator.class);
 
     private static final Map<String, SnowflakeIdGenerator> INSTANCES =
-                         new ConcurrentHashMap<>();
+            new ConcurrentHashMap<>();
 
     private final boolean forceString;
     private final IdWorker idWorker;
@@ -114,13 +113,13 @@ public class SnowflakeIdGenerator extends IdGenerator {
             // Sanity check for workerId
             if (workerId > MAX_WORKER_ID || workerId < 0) {
                 throw new IllegalArgumentException(String.format(
-                          "Worker id can't > %d or < 0",
-                          MAX_WORKER_ID));
+                        "Worker id can't > %d or < 0",
+                        MAX_WORKER_ID));
             }
             if (datacenterId > MAX_DC_ID || datacenterId < 0) {
                 throw new IllegalArgumentException(String.format(
-                          "Datacenter id can't > %d or < 0",
-                          MAX_DC_ID));
+                        "Datacenter id can't > %d or < 0",
+                        MAX_DC_ID));
             }
             this.workerId = workerId;
             this.datacenterId = datacenterId;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SplicingIdGenerator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SplicingIdGenerator.java
index 7e6e29262..47f098fa7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SplicingIdGenerator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/id/SplicingIdGenerator.java
@@ -70,8 +70,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Concat multiple ids into one composite id with IDS_SPLITOR
+     *
      * @param ids the string id values to be concatted
-     * @return    concatted string value
+     * @return concatted string value
      */
     public static String concat(String... ids) {
         // NOTE: must support string id when using this method
@@ -80,8 +81,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Split a composite id into multiple ids with IDS_SPLITOR
+     *
      * @param ids the string id value to be splitted
-     * @return    splitted string values
+     * @return splitted string values
      */
     public static String[] split(String ids) {
         return IdUtil.unescape(ids, IDS_SPLITOR_STR, ESCAPE_STR);
@@ -89,8 +91,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Concat property values with NAME_SPLITOR
+     *
      * @param values the property values to be concatted
-     * @return       concatted string value
+     * @return concatted string value
      */
     public static String concatValues(List<?> values) {
         // Convert the object list to string array
@@ -104,8 +107,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Concat property values with NAME_SPLITOR
+     *
      * @param values the property values to be concatted
-     * @return       concatted string value
+     * @return concatted string value
      */
     public static String concatValues(Object... values) {
         return concatValues(Arrays.asList(values));
@@ -113,8 +117,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Concat multiple parts into a single id with ID_SPLITOR
+     *
      * @param parts the string id values to be spliced
-     * @return      spliced id object
+     * @return spliced id object
      */
     public static Id splicing(String... parts) {
         String escaped = IdUtil.escape(ID_SPLITOR, ESCAPE, parts);
@@ -123,8 +128,9 @@ public class SplicingIdGenerator extends IdGenerator {
 
     /**
      * Parse a single id into multiple parts with ID_SPLITOR
+     *
      * @param id the id object to be parsed
-     * @return   parsed string id parts
+     * @return parsed string id parts
      */
     public static String[] parse(Id id) {
         return IdUtil.unescape(id.asString(), ID_SPLITOR_STR, ESCAPE_STR);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/IdHolder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/IdHolder.java
index 37fe46350..b42064876 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/IdHolder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/IdHolder.java
@@ -23,15 +23,14 @@ import java.util.Set;
 import java.util.function.Function;
 
 import org.apache.commons.lang.NotImplementedException;
+import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
-import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.iterator.CIter;
 import org.apache.hugegraph.iterator.Metadatable;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
 public abstract class IdHolder {
 
@@ -133,7 +132,7 @@ public abstract class IdHolder {
     }
 
     public static class BatchIdHolder extends IdHolder
-                                      implements CIter<IdHolder> {
+            implements CIter<IdHolder> {
 
         private final Iterator<BackendEntry> entries;
         private final Function<Long, Set<Id>> fetcher;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageEntryIterator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageEntryIterator.java
index 5d8370824..bbc93c79b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageEntryIterator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageEntryIterator.java
@@ -21,11 +21,10 @@ import java.util.NoSuchElementException;
 
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
 import org.apache.hugegraph.exception.NotSupportException;
 import org.apache.hugegraph.iterator.CIter;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
 public class PageEntryIterator<R> implements CIter<R> {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageIds.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageIds.java
index 96b9d25cc..879821f3d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageIds.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/PageIds.java
@@ -20,6 +20,7 @@ package org.apache.hugegraph.backend.page;
 import java.util.Set;
 
 import org.apache.hugegraph.backend.id.Id;
+
 import com.google.common.collect.ImmutableSet;
 
 public final class PageIds {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/QueryList.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/QueryList.java
index 7eb10e016..d1e11e922 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/QueryList.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/QueryList.java
@@ -22,14 +22,14 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.page.IdHolder.BatchIdHolder;
+import org.apache.hugegraph.backend.page.IdHolder.FixedIdHolder;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.ConditionQuery.OptimizedType;
 import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.backend.page.IdHolder.BatchIdHolder;
-import org.apache.hugegraph.backend.page.IdHolder.FixedIdHolder;
 import org.apache.hugegraph.util.Bytes;
 import org.apache.hugegraph.util.E;
 
@@ -46,7 +46,7 @@ public final class QueryList<R> {
         this.queries = new ArrayList<>();
     }
 
-    protected Query parent() {
+    Query parent() {
         return this.parent;
     }
 
@@ -98,7 +98,7 @@ public final class QueryList<R> {
         return QueryResults.flatMap(this.queries.iterator(), FlattenQuery::iterator);
     }
 
-    protected PageResults<R> fetchNext(PageInfo pageInfo, long pageSize) {
+    PageResults<R> fetchNext(PageInfo pageInfo, long pageSize) {
         FlattenQuery<R> query = null;
         int offset = pageInfo.offset();
         int visited = 0;
@@ -126,16 +126,18 @@ public final class QueryList<R> {
 
         /**
          * For non-paging situation
-         * @return          BackendEntry iterator
+         *
+         * @return BackendEntry iterator
          */
         QueryResults<R> iterator();
 
         /**
          * For paging situation
-         * @param index     position IdHolder(Query)
-         * @param page      set query page
-         * @param pageSize  set query page size
-         * @return          BackendEntry iterator with page
+         *
+         * @param index    position IdHolder(Query)
+         * @param page     set query page
+         * @param pageSize set query page size
+         * @return BackendEntry iterator with page
          */
         PageResults<R> iterator(int index, String page, long pageSize);
 
@@ -323,8 +325,8 @@ public final class QueryList<R> {
     public static class PageResults<R> {
 
         public static final PageResults<?> EMPTY = new PageResults<>(
-                                                   QueryResults.empty(),
-                                                   PageState.EMPTY);
+                QueryResults.empty(),
+                PageState.EMPTY);
 
         private final QueryResults<R> results;
         private final PageState pageState;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/SortByCountIdHolderList.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/SortByCountIdHolderList.java
index f2daad0d4..eeac97867 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/SortByCountIdHolderList.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/page/SortByCountIdHolderList.java
@@ -22,11 +22,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.page.IdHolder.FixedIdHolder;
+import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.util.CollectionUtil;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableSet;
 
 public class SortByCountIdHolderList extends IdHolderList {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/BatchConditionQuery.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/BatchConditionQuery.java
index 99da61efe..181ee4864 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/BatchConditionQuery.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/BatchConditionQuery.java
@@ -43,7 +43,7 @@ public class BatchConditionQuery extends ConditionQuery {
         if (this.in == null) {
             assert !this.containsRelation(RelationType.IN);
             this.resetConditions(InsertionOrderUtil.newList(
-                                 (List<Condition>) query.conditions()));
+                    (List<Condition>) query.conditions()));
             this.unsetCondition(key);
 
             List<Object> list = new ArrayList<>(this.batchSize);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Condition.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Condition.java
index d3746470d..4756a729c 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Condition.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Condition.java
@@ -17,7 +17,6 @@
 
 package org.apache.hugegraph.backend.query;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Date;
@@ -29,9 +28,8 @@ import java.util.function.BiFunction;
 import java.util.function.BiPredicate;
 
 import org.apache.commons.lang.ArrayUtils;
-
-import org.apache.hugegraph.backend.store.Shard;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.store.Shard;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.type.define.HugeKeys;
@@ -39,6 +37,7 @@ import org.apache.hugegraph.util.Bytes;
 import org.apache.hugegraph.util.DateUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.NumericUtil;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -49,7 +48,7 @@ public abstract class Condition {
         RELATION,
         AND,
         OR,
-        NOT;
+        NOT
     }
 
     public enum RelationType implements BiPredicate<Object, Object> {
@@ -146,12 +145,12 @@ public abstract class Condition {
         private final Class<?> v2Class;
 
         RelationType(String op,
-                             BiFunction<Object, Object, Boolean> tester) {
+                     BiFunction<Object, Object, Boolean> tester) {
             this(op, null, null, tester);
         }
 
         RelationType(String op, Class<?> v1Class, Class<?> v2Class,
-                             BiFunction<Object, Object, Boolean> tester) {
+                     BiFunction<Object, Object, Boolean> tester) {
             this.operator = op;
             this.tester = tester;
             this.v1Class = v1Class;
@@ -164,7 +163,8 @@ public abstract class Condition {
 
         /**
          * Determine two values of any type equal
-         * @param first is actual value
+         *
+         * @param first  is actual value
          * @param second is value in query condition
          * @return true if equal, otherwise false
          */
@@ -188,13 +188,14 @@ public abstract class Condition {
 
         /**
          * Determine two numbers equal
-         * @param first is actual value, might be Number/Date or String, It is
-         *              probably that the `first` is serialized to String.
+         *
+         * @param first  is actual value, might be Number/Date or String, It is
+         *               probably that the `first` is serialized to String.
          * @param second is value in query condition, must be Number/Date
          * @return the value 0 if first is numerically equal to second;
-         *         a value less than 0 if first is numerically less than
-         *         second; and a value greater than 0 if first is
-         *         numerically greater than second.
+         * a value less than 0 if first is numerically less than
+         * second; and a value greater than 0 if first is
+         * numerically greater than second.
          */
         private static int compare(final Object first, final Object second) {
             assert second != null;
@@ -206,9 +207,9 @@ public abstract class Condition {
             }
 
             throw new IllegalArgumentException(String.format(
-                      "Can't compare between %s(%s) and %s(%s)", first,
-                      first == null ? null : first.getClass().getSimpleName(),
-                      second, second.getClass().getSimpleName()));
+                    "Can't compare between %s(%s) and %s(%s)", first,
+                    first == null ? null : first.getClass().getSimpleName(),
+                    second, second.getClass().getSimpleName()));
         }
 
         private static int compareDate(Object first, Date second) {
@@ -220,9 +221,9 @@ public abstract class Condition {
             }
 
             throw new IllegalArgumentException(String.format(
-                      "Can't compare between %s(%s) and %s(%s)",
-                      first, first.getClass().getSimpleName(),
-                      second, second.getClass().getSimpleName()));
+                    "Can't compare between %s(%s) and %s(%s)",
+                    first, first.getClass().getSimpleName(),
+                    second, second.getClass().getSimpleName()));
         }
 
         private void checkBaseType(Object value, Class<?> clazz) {
@@ -543,7 +544,8 @@ public abstract class Condition {
         }
     }
 
-    public static class Not extends Condition implements Serializable {
+    public static class Not extends Condition {
+
         Condition condition;
 
         public Not(Condition condition) {
@@ -629,8 +631,8 @@ public abstract class Condition {
         protected Object serialValue;
 
         protected static final Set<RelationType> UNFLATTEN_RELATION_TYPES =
-                  ImmutableSet.of(RelationType.IN, RelationType.NOT_IN,
-                                  RelationType.TEXT_CONTAINS_ANY);
+                ImmutableSet.of(RelationType.IN, RelationType.NOT_IN,
+                                RelationType.TEXT_CONTAINS_ANY);
 
         @Override
         public ConditionType type() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQuery.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQuery.java
index f40870009..50ef774e3 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQuery.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQuery.java
@@ -63,10 +63,11 @@ public class ConditionQuery extends IdQuery {
     public static final char INDEX_SYM_MAX = '\u0003';
 
     // Note: here we use "new String" to distinguish normal string code
-    public static final String INDEX_VALUE_NULL = new String("<null>");
-    public static final String INDEX_VALUE_EMPTY = new String("<empty>");
+    public static final String INDEX_VALUE_NULL = "<null>";
+    public static final String INDEX_VALUE_EMPTY = "<empty>";
 
     public static final Set<String> IGNORE_SYM_SET;
+
     static {
         List<String> list = new ArrayList<>(INDEX_SYM_MAX - INDEX_SYM_MIN);
         for (char ch = INDEX_SYM_MIN; ch <= INDEX_SYM_MAX; ch++) {
@@ -472,6 +473,7 @@ public class ConditionQuery extends IdQuery {
     /**
      * This method is only used for secondary index scenario,
      * its relation must be EQ
+     *
      * @param fields the user property fields
      * @return the corresponding user property serial values of fields
      */
@@ -493,8 +495,8 @@ public class ConditionQuery extends IdQuery {
             }
             if (!got) {
                 throw new BackendException(
-                          "No such userprop named '%s' in the query '%s'",
-                          field, this);
+                        "No such userprop named '%s' in the query '%s'",
+                        field, this);
             }
         }
         return concatValues(values);
@@ -652,7 +654,7 @@ public class ConditionQuery extends IdQuery {
 
     public void optimized(OptimizedType optimizedType) {
         assert this.optimizedType.ordinal() <= optimizedType.ordinal() :
-               this.optimizedType + " !<= " + optimizedType;
+                this.optimizedType + " !<= " + optimizedType;
         this.optimizedType = optimizedType;
 
         Query originQuery = this.originQuery();
@@ -722,7 +724,8 @@ public class ConditionQuery extends IdQuery {
     public static String concatValues(Object value) {
         if (value instanceof String) {
             return escapeSpecialValueIfNeeded((String) value);
-        } if (value instanceof List) {
+        }
+        if (value instanceof List) {
             return concatValues((List<?>) value);
         } else if (needConvertNumber(value)) {
             return LongEncoding.encodeNumber(value);
@@ -798,7 +801,7 @@ public class ConditionQuery extends IdQuery {
                 this.filed2IndexValues.putIfAbsent(indexField, new HashMap<>());
             }
             Map<Id, Set<Object>> element2IndexValueMap =
-                                 this.filed2IndexValues.get(indexField);
+                    this.filed2IndexValues.get(indexField);
             if (element2IndexValueMap.containsKey(elementId)) {
                 element2IndexValueMap.get(elementId).add(indexValue);
             } else {
@@ -843,7 +846,7 @@ public class ConditionQuery extends IdQuery {
             }
 
             Condition.UserpropRelation propRelation =
-                                       (Condition.UserpropRelation) cond;
+                    (Condition.UserpropRelation) cond;
             Id propId = propRelation.key();
             Set<Object> fieldValues = this.toRemoveIndexValues(propId,
                                                                element.id());
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQueryFlatten.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQueryFlatten.java
index fc488cc4b..83af41b00 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQueryFlatten.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQueryFlatten.java
@@ -40,7 +40,7 @@ import com.google.common.collect.ImmutableSet;
 public final class ConditionQueryFlatten {
 
     private static final Set<HugeKeys> SPECIAL_KEYS = ImmutableSet.of(
-        HugeKeys.LABEL
+            HugeKeys.LABEL
     );
 
     public static List<ConditionQuery> flatten(ConditionQuery query) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/IdQuery.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/IdQuery.java
index e5e3c9a3a..f7a1c732b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/IdQuery.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/IdQuery.java
@@ -27,6 +27,7 @@ import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -157,7 +158,7 @@ public class IdQuery extends Query {
         @Override
         public Set<Id> ids() {
             return this.id == null ? ImmutableSet.of() :
-                                     ImmutableSet.of(this.id);
+                   ImmutableSet.of(this.id);
         }
 
         @Override
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Query.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Query.java
index b3115eb4a..593887d92 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Query.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/Query.java
@@ -412,8 +412,8 @@ public class Query implements Cloneable {
                 query = query.substring(0, MAX_CHARS) + "...";
             }
             throw new LimitExceedException(
-                      "Too many records(must <= %s) for the query: %s",
-                      this.capacity, query);
+                    "Too many records(must <= %s) for the query: %s",
+                    this.capacity, query);
         }
     }
 
@@ -611,8 +611,8 @@ public class Query implements Cloneable {
     public static void checkForceCapacity(long count) throws LimitExceedException {
         if (count > Query.DEFAULT_CAPACITY) {
             throw new LimitExceedException(
-                      "Too many records(must <= %s) for one query",
-                      Query.DEFAULT_CAPACITY);
+                    "Too many records(must <= %s) for one query",
+                    Query.DEFAULT_CAPACITY);
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/QueryResults.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/QueryResults.java
index 12440dfee..ca457a63a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/QueryResults.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/QueryResults.java
@@ -26,8 +26,6 @@ import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.function.Function;
 
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.iterator.CIter;
@@ -38,13 +36,14 @@ import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.type.Idfiable;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
 public class QueryResults<R> {
 
     private static final Iterator<?> EMPTY_ITERATOR = new EmptyIterator<>();
 
     private static final QueryResults<?> EMPTY = new QueryResults<>(
-                                                 emptyIterator(), Query.NONE);
+            emptyIterator(), Query.NONE);
 
     private final Iterator<R> results;
     private final List<Query> queries;
@@ -97,7 +96,7 @@ public class QueryResults<R> {
     }
 
     public <T extends Idfiable> Iterator<T> keepInputOrderIfNeeded(
-                                            Iterator<T> origin) {
+            Iterator<T> origin) {
         if (!origin.hasNext()) {
             // None result found
             return origin;
@@ -216,7 +215,7 @@ public class QueryResults<R> {
     }
 
     public static <T, R> QueryResults<R> flatMap(
-                  Iterator<T> iterator, Function<T, QueryResults<R>> func) {
+            Iterator<T> iterator, Function<T, QueryResults<R>> func) {
         @SuppressWarnings("unchecked")
         QueryResults<R>[] qr = new QueryResults[1];
         qr[0] = new QueryResults<>(new FlatMapperIterator<>(iterator, i -> {
@@ -266,7 +265,9 @@ public class QueryResults<R> {
         return (Iterator<T>) EMPTY_ITERATOR;
     }
 
-    public interface Fetcher<R> extends Function<Query, QueryResults<R>> {}
+    public interface Fetcher<R> extends Function<Query, QueryResults<R>> {
+
+    }
 
     private static class EmptyIterator<T> implements CIter<T> {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/AbstractSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/AbstractSerializer.java
index ffebc4dcf..734cb9042 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/AbstractSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/AbstractSerializer.java
@@ -19,20 +19,18 @@ package org.apache.hugegraph.backend.serializer;
 
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.iterator.CIter;
-import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.config.HugeConfig;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 
 public abstract class AbstractSerializer
-                implements GraphSerializer, SchemaSerializer {
+        implements GraphSerializer, SchemaSerializer {
 
     protected HugeConfig config;
 
@@ -41,7 +39,7 @@ public abstract class AbstractSerializer
     }
 
     public AbstractSerializer(HugeConfig config) {
-       this.config = config;
+        this.config = config;
     }
 
     protected BackendEntry convertEntry(BackendEntry entry) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinaryScatterSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinaryScatterSerializer.java
index 3e0c8f2a7..18b642a00 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinaryScatterSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinaryScatterSerializer.java
@@ -22,12 +22,12 @@ import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
+import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.structure.HugeVertexProperty;
 import org.apache.hugegraph.type.define.HugeKeys;
-import org.apache.hugegraph.config.HugeConfig;
 
 public class BinaryScatterSerializer extends BinarySerializer {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinarySerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinarySerializer.java
index d46ba8371..9f5e37ce1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinarySerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BinarySerializer.java
@@ -17,8 +17,6 @@
 
 package org.apache.hugegraph.backend.serializer;
 
-import static org.apache.hugegraph.schema.SchemaElement.UNDEF;
-
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
@@ -26,20 +24,12 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.commons.lang.NotImplementedException;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.page.PageState;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
-import org.apache.hugegraph.iterator.CIter;
-import org.apache.hugegraph.iterator.MapperIterator;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.type.define.EdgeLabelType;
-import org.apache.hugegraph.util.*;
 import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.Condition.RangeConditions;
 import org.apache.hugegraph.backend.query.ConditionQuery;
@@ -47,7 +37,11 @@ import org.apache.hugegraph.backend.query.IdPrefixQuery;
 import org.apache.hugegraph.backend.query.IdRangeQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.serializer.BinaryBackendEntry.BinaryId;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
 import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.iterator.CIter;
+import org.apache.hugegraph.iterator.MapperIterator;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.PropertyKey;
@@ -60,6 +54,7 @@ import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.structure.HugeVertexProperty;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.AggregateType;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
@@ -71,7 +66,10 @@ import org.apache.hugegraph.type.define.IndexType;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.type.define.SerialEnum;
 import org.apache.hugegraph.type.define.WriteType;
+import org.apache.hugegraph.util.Bytes;
+import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
+import org.apache.hugegraph.util.NumericUtil;
 import org.apache.hugegraph.util.StringEncoding;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 
@@ -214,7 +212,7 @@ public class BinarySerializer extends AbstractSerializer {
         } else {
             if (!(value instanceof Collection)) {
                 throw new BackendException(
-                          "Invalid value of non-single property: %s", value);
+                        "Invalid value of non-single property: %s", value);
             }
             owner.addProperty(pkey, value);
         }
@@ -532,7 +530,6 @@ public class BinarySerializer extends AbstractSerializer {
 
     @Override
     public CIter<Edge> readEdges(HugeGraph graph, BackendEntry bytesEntry) {
-
         BinaryBackendEntry entry = this.convertEntry(bytesEntry);
 
         // Parse id
@@ -914,7 +911,9 @@ public class BinarySerializer extends AbstractSerializer {
         buffer.write(parsedEntry.id().asBytes());
         buffer.write(bytes);
         parsedEntry = new BinaryBackendEntry(originEntry.type(), new BinaryId(buffer.bytes(),
-                                             BytesBuffer.wrap(buffer.bytes()).readEdgeId()));
+                                                                              BytesBuffer.wrap(
+                                                                                                 buffer.bytes())
+                                                                                         .readEdgeId()));
 
         for (BackendColumn col : originEntry.columns()) {
             parsedEntry.column(buffer.bytes(), col.value);
@@ -962,9 +961,7 @@ public class BinarySerializer extends AbstractSerializer {
     protected static boolean indexFieldValuesUnmatched(byte[] value,
                                                        Object fieldValues) {
         if (value != null && value.length > 0 && fieldValues != null) {
-            if (!StringEncoding.decode(value).equals(fieldValues)) {
-                return true;
-            }
+            return !StringEncoding.decode(value).equals(fieldValues);
         }
         return false;
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BytesBuffer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BytesBuffer.java
index add37f701..f293dd287 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BytesBuffer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BytesBuffer.java
@@ -18,7 +18,6 @@
 package org.apache.hugegraph.backend.serializer;
 
 import java.io.OutputStream;
-import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.Collection;
@@ -29,13 +28,14 @@ import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.Id.IdType;
 import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.backend.serializer.BinaryBackendEntry.BinaryId;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
-import org.apache.hugegraph.util.*;
-import org.apache.hugegraph.backend.serializer.BinaryBackendEntry.BinaryId;
 import org.apache.hugegraph.util.Blob;
+import org.apache.hugegraph.util.Bytes;
+import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.KryoUtil;
 import org.apache.hugegraph.util.StringEncoding;
 
@@ -170,7 +170,7 @@ public final class BytesBuffer extends OutputStream {
                         "Capacity exceeds max buffer capacity: %s",
                         MAX_BUFFER_CAPACITY);
         ByteBuffer newBuffer = ByteBuffer.allocate(newCapacity);
-        ((Buffer) this.buffer).flip();
+        this.buffer.flip();
         newBuffer.put(this.buffer);
         this.buffer = newBuffer;
     }
@@ -344,7 +344,7 @@ public final class BytesBuffer extends OutputStream {
              *   0xFF is not a valid byte in UTF8 bytes
              */
             assert !Bytes.contains(bytes, STRING_ENDING_BYTE_FF) :
-                   "Invalid UTF8 bytes: " + value;
+                    "Invalid UTF8 bytes: " + value;
             if (Bytes.contains(bytes, STRING_ENDING_BYTE)) {
                 E.checkArgument(false,
                                 "Can't contains byte '0x00' in string: '%s'",
@@ -421,7 +421,7 @@ public final class BytesBuffer extends OutputStream {
             this.write(0x80 | ((value >>> 14) & 0x7f));
         }
         if (value > 0x7f || value < 0) {
-            this.write(0x80 | ((value >>>  7) & 0x7f));
+            this.write(0x80 | ((value >>> 7) & 0x7f));
         }
         this.write(value & 0x7f);
 
@@ -485,7 +485,7 @@ public final class BytesBuffer extends OutputStream {
             this.write(0x80 | ((int) (value >>> 14) & 0x7f));
         }
         if (value > 0x7fL || value < 0L) {
-            this.write(0x80 | ((int) (value >>>  7) & 0x7f));
+            this.write(0x80 | ((int) (value >>> 7) & 0x7f));
         }
         this.write((int) value & 0x7f);
 
@@ -906,7 +906,7 @@ public final class BytesBuffer extends OutputStream {
                 value |= this.readUInt16();
                 break;
             case 2:
-                value |= this.readUInt8() << 16 | this.readUInt16();
+                value |= (long) this.readUInt8() << 16 | this.readUInt16();
                 break;
             case 3:
                 value |= this.readUInt32();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/GraphSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/GraphSerializer.java
index 3b65130eb..2d14df1c8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/GraphSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/GraphSerializer.java
@@ -23,12 +23,12 @@ import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.iterator.CIter;
-import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.structure.HugeEdgeProperty;
 import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.structure.HugeVertexProperty;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 
 public interface GraphSerializer {
@@ -46,6 +46,7 @@ public interface GraphSerializer {
     BackendEntry writeEdgeProperty(HugeEdgeProperty<?> prop);
 
     HugeEdge readEdge(HugeGraph graph, BackendEntry entry);
+
     CIter<Edge> readEdges(HugeGraph graph, BackendEntry bytesEntry);
 
     BackendEntry writeIndex(HugeIndex index);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/MergeIterator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/MergeIterator.java
index a88562623..fa7cfe954 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/MergeIterator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/MergeIterator.java
@@ -36,12 +36,12 @@ public class MergeIterator<T, R> extends WrappedIterator<T> {
                          List<Iterator<R>> iterators,
                          BiFunction<T, R, Boolean> merger) {
         E.checkArgumentNotNull(originIterator, "The origin iterator of " +
-                               "MergeIterator can't be null");
+                                               "MergeIterator can't be null");
         E.checkArgument(iterators != null && !iterators.isEmpty(),
                         "The iterators of MergeIterator can't be " +
                         "null or empty");
         E.checkArgumentNotNull(merger, "The merger function of " +
-                               "MergeIterator can't be null");
+                                       "MergeIterator can't be null");
         this.originIterator = originIterator;
         this.headElements = new ArrayList<>();
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/SerializerFactory.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/SerializerFactory.java
index 39b52c716..db5fe0a8c 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/SerializerFactory.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/SerializerFactory.java
@@ -56,7 +56,7 @@ public class SerializerFactory {
         }
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public static void register(String name, String classPath) {
         ClassLoader classLoader = SerializerFactory.class.getClassLoader();
         Class<?> clazz;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableBackendEntry.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableBackendEntry.java
index c33cd97aa..918a95b51 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableBackendEntry.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableBackendEntry.java
@@ -27,7 +27,6 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.commons.lang3.NotImplementedException;
-
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.type.HugeType;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableSerializer.java
index 9d3826098..fbca2a9a1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TableSerializer.java
@@ -32,8 +32,6 @@ import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
@@ -48,6 +46,7 @@ import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.structure.HugeVertexProperty;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.AggregateType;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
@@ -60,6 +59,7 @@ import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.type.define.SerialEnum;
 import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
 
 public abstract class TableSerializer extends AbstractSerializer {
 
@@ -108,7 +108,7 @@ public abstract class TableSerializer extends AbstractSerializer {
         } else {
             if (!(value instanceof Collection)) {
                 throw new BackendException(
-                          "Invalid value of non-single property: %s", value);
+                        "Invalid value of non-single property: %s", value);
             }
             owner.addProperty(pkey, value);
         }
@@ -157,9 +157,10 @@ public abstract class TableSerializer extends AbstractSerializer {
 
     /**
      * Parse an edge from a entry row
-     * @param row edge entry
+     *
+     * @param row    edge entry
      * @param vertex null or the source vertex
-     * @param graph the HugeGraph context object
+     * @param graph  the HugeGraph context object
      * @return the source vertex
      */
     protected HugeEdge parseEdge(TableBackendEntry.Row row,
@@ -560,8 +561,8 @@ public abstract class TableSerializer extends AbstractSerializer {
         AggregateType aggregateType = schemaEnum(entry, HugeKeys.AGGREGATE_TYPE,
                                                  AggregateType.class);
         WriteType writeType = schemaEnumOrDefault(
-                              entry, HugeKeys.WRITE_TYPE,
-                              WriteType.class, WriteType.OLTP);
+                entry, HugeKeys.WRITE_TYPE,
+                WriteType.class, WriteType.OLTP);
         Object properties = schemaColumn(entry, HugeKeys.PROPERTIES);
         SchemaStatus status = schemaEnum(entry, HugeKeys.STATUS,
                                          SchemaStatus.class);
@@ -697,9 +698,9 @@ public abstract class TableSerializer extends AbstractSerializer {
     }
 
     private static <T extends SerialEnum> T schemaEnumOrDefault(
-                                            TableBackendEntry entry,
-                                            HugeKeys key, Class<T> clazz,
-                                            T defaultValue) {
+            TableBackendEntry entry,
+            HugeKeys key, Class<T> clazz,
+            T defaultValue) {
         assert entry.type().isSchema();
 
         Number value = entry.column(key);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextBackendEntry.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextBackendEntry.java
index 871da9989..2dfdb2cba 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextBackendEntry.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextBackendEntry.java
@@ -165,7 +165,7 @@ public class TextBackendEntry implements BackendEntry, Cloneable {
     }
 
     public boolean containsValue(String value) {
-        return this.columns.values().contains(value);
+        return this.columns.containsValue(value);
     }
 
     public void append(TextBackendEntry entry) {
@@ -371,6 +371,7 @@ public class TextBackendEntry implements BackendEntry, Cloneable {
         return true;
     }
 
+    @Override
     public int hashCode() {
         return this.id().hashCode() ^ this.columns().hashCode();
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextSerializer.java
index 9d7b3bcfd..ed6c12241 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/TextSerializer.java
@@ -23,16 +23,10 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.commons.lang.NotImplementedException;
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.config.HugeConfig;
-import org.apache.commons.lang.NotImplementedException;
-
-import org.apache.hugegraph.iterator.CIter;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -43,6 +37,9 @@ import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.IdPrefixQuery;
 import org.apache.hugegraph.backend.query.IdRangeQuery;
 import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.iterator.CIter;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.PropertyKey;
@@ -56,6 +53,7 @@ import org.apache.hugegraph.structure.HugeIndex.IdWithExpiredTime;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.structure.HugeVertexProperty;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.AggregateType;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
@@ -67,6 +65,7 @@ import org.apache.hugegraph.type.define.IndexType;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 
 import com.google.common.collect.ImmutableMap;
@@ -75,7 +74,7 @@ public class TextSerializer extends AbstractSerializer {
 
     private static final String VALUE_SPLITOR = TextBackendEntry.VALUE_SPLITOR;
     private static final String EDGE_NAME_ENDING =
-                                ConditionQuery.INDEX_SYM_ENDING;
+            ConditionQuery.INDEX_SYM_ENDING;
 
     private static final String EDGE_OUT_TYPE = writeType(HugeType.EDGE_OUT);
 
@@ -166,7 +165,7 @@ public class TextSerializer extends AbstractSerializer {
         } else {
             if (!(value instanceof Collection)) {
                 throw new BackendException(
-                          "Invalid value of non-single property: %s", colValue);
+                        "Invalid value of non-single property: %s", colValue);
             }
             for (Object v : (Collection<?>) value) {
                 v = JsonUtil.castNumber(v, pkey.dataType().clazz());
@@ -316,7 +315,7 @@ public class TextSerializer extends AbstractSerializer {
         HugeVertex vertex = new HugeVertex(graph, id, vertexLabel);
 
         String expiredTime = entry.column(this.formatSyspropName(
-                             HugeKeys.EXPIRED_TIME));
+                HugeKeys.EXPIRED_TIME));
         // Expired time is null when backend entry is fake vertex with edges
         if (expiredTime != null) {
             vertex.expiredTime(readLong(expiredTime));
@@ -395,11 +394,11 @@ public class TextSerializer extends AbstractSerializer {
 
         TextBackendEntry entry = this.convertEntry(backendEntry);
         String indexValues = entry.column(
-                             formatSyspropName(HugeKeys.FIELD_VALUES));
+                formatSyspropName(HugeKeys.FIELD_VALUES));
         String indexLabelId = entry.column(
-                              formatSyspropName(HugeKeys.INDEX_LABEL_ID));
+                formatSyspropName(HugeKeys.INDEX_LABEL_ID));
         String elemIds = entry.column(
-                         formatSyspropName(HugeKeys.ELEMENT_IDS));
+                formatSyspropName(HugeKeys.ELEMENT_IDS));
 
         IndexLabel indexLabel = IndexLabel.label(graph, readId(indexLabelId));
         HugeIndex index = new HugeIndex(graph, indexLabel);
@@ -875,7 +874,7 @@ public class TextSerializer extends AbstractSerializer {
                 Map<String, Object> map = (Map<String, Object>) values[i];
                 idValue = map.get(HugeKeys.ID.string());
                 expiredTime = ((Number) map.get(
-                              HugeKeys.EXPIRED_TIME.string())).longValue();
+                        HugeKeys.EXPIRED_TIME.string())).longValue();
             } else {
                 idValue = values[i];
                 expiredTime = 0L;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStore.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStore.java
index d1cc0515d..2ef9a6db7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStore.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStore.java
@@ -21,7 +21,7 @@ import org.apache.hugegraph.exception.ConnectionException;
 import org.apache.hugegraph.type.HugeType;
 
 public abstract class AbstractBackendStore<Session extends BackendSession>
-                implements BackendStore {
+        implements BackendStore {
 
     // TODO: move SystemSchemaStore into backend like MetaStore
     private final SystemSchemaStore systemSchemaStore;
@@ -43,7 +43,7 @@ public abstract class AbstractBackendStore<Session extends BackendSession>
     @Override
     public String storedVersion() {
         throw new UnsupportedOperationException(
-                  "AbstractBackendStore.storedVersion()");
+                "AbstractBackendStore.storedVersion()");
     }
 
     @Override
@@ -68,8 +68,8 @@ public abstract class AbstractBackendStore<Session extends BackendSession>
     protected void checkOpened() throws ConnectionException {
         if (!this.opened()) {
             throw new ConnectionException(
-                      "The '%s' store of %s has not been opened",
-                      this.database(), this.provider().type());
+                    "The '%s' store of %s has not been opened",
+                    this.database(), this.provider().type());
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStoreProvider.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStoreProvider.java
index bfd9031ce..906d79514 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStoreProvider.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/AbstractBackendStoreProvider.java
@@ -21,11 +21,8 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Future;
 
-import org.apache.hugegraph.backend.store.raft.StoreSnapshotFile;
-import org.slf4j.Logger;
-
-import com.alipay.remoting.rpc.RpcServer;
 import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.backend.store.raft.StoreSnapshotFile;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.event.EventHub;
@@ -33,9 +30,12 @@ import org.apache.hugegraph.event.EventListener;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Events;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.alipay.remoting.rpc.RpcServer;
 
 public abstract class AbstractBackendStoreProvider
-                implements BackendStoreProvider {
+        implements BackendStoreProvider {
 
     private static final Logger LOG = Log.logger(AbstractBackendStoreProvider.class);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendEntryIterator.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendEntryIterator.java
index 4ffb3660a..f13798dd6 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendEntryIterator.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendEntryIterator.java
@@ -213,7 +213,6 @@ public abstract class BackendEntryIterator implements CIter<BackendEntry> {
 
         @Override
         public void close() throws Exception {
-            return;
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendMutation.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendMutation.java
index d1ed76725..02b342900 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendMutation.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendMutation.java
@@ -46,7 +46,8 @@ public class BackendMutation {
 
     /**
      * Add data entry with an action to collection `updates`
-     * @param entry the backend entry
+     *
+     * @param entry  the backend entry
      * @param action operate action on the entry
      */
     @Watched(prefix = "mutation")
@@ -72,11 +73,11 @@ public class BackendMutation {
     /**
      * The optimized scenes include but are not limited to:
      * 1.If you want to delete an entry, the other mutations previously
-     *   can be ignored.
+     * can be ignored.
      * 2.As similar to the No.1 item, If you want to insert an entry,
-     *   the other mutations previously also can be ignored.
+     * the other mutations previously also can be ignored.
      * 3.If you append an entry and then eliminate it, the new action
-     *   can override the old one.
+     * can override the old one.
      */
     @Watched(prefix = "mutation")
     private void optimizeUpdates(BackendEntry entry, Action action) {
@@ -85,7 +86,7 @@ public class BackendMutation {
         final List<BackendAction> items = this.updates.get(entry.type(), id);
         assert items != null;
         boolean ignoreCurrent = false;
-        for (Iterator<BackendAction> iter = items.iterator(); iter.hasNext();) {
+        for (Iterator<BackendAction> iter = items.iterator(); iter.hasNext(); ) {
             BackendAction originItem = iter.next();
             Action originAction = originItem.action();
             switch (action) {
@@ -105,9 +106,9 @@ public class BackendMutation {
                     if (entry.type().isUniqueIndex() &&
                         originAction == Action.APPEND) {
                         throw new IllegalArgumentException(String.format(
-                                  "Unique constraint conflict is found in" +
-                                  " transaction between %s and %s",
-                                  entry, originItem.entry()));
+                                "Unique constraint conflict is found in" +
+                                " transaction between %s and %s",
+                                entry, originItem.entry()));
                     }
 
                     if (originAction == Action.INSERT ||
@@ -137,7 +138,7 @@ public class BackendMutation {
                     break;
                 default:
                     throw new AssertionError(String.format(
-                              "Unknown mutate action: %s", action));
+                            "Unknown mutate action: %s", action));
             }
         }
         if (!ignoreCurrent) {
@@ -146,8 +147,8 @@ public class BackendMutation {
     }
 
     private static HugeException incompatibleActionException(
-                                 Action newAction,
-                                 Action originAction) {
+            Action newAction,
+            Action originAction) {
         return new HugeException("The action '%s' is incompatible with " +
                                  "action '%s'", newAction, originAction);
     }
@@ -156,11 +157,12 @@ public class BackendMutation {
      * Merges another mutation into this mutation. Ensures that all additions
      * and deletions are added to this mutation. Does not remove duplicates
      * if such exist - this needs to be ensured by the caller.
+     *
      * @param mutation another mutation to be merged
      */
     public void merge(BackendMutation mutation) {
         E.checkNotNull(mutation, "mutation");
-        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext();) {
+        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext(); ) {
             BackendAction item = it.next();
             this.add(item.entry(), item.action());
         }
@@ -172,6 +174,7 @@ public class BackendMutation {
 
     /**
      * Get all mutations
+     *
      * @return mutations
      */
     public Iterator<BackendAction> mutation() {
@@ -180,6 +183,7 @@ public class BackendMutation {
 
     /**
      * Get mutations by type
+     *
      * @param type entry type
      * @return mutations
      */
@@ -189,8 +193,9 @@ public class BackendMutation {
 
     /**
      * Get mutations by type and id
+     *
      * @param type entry type
-     * @param id entry id
+     * @param id   entry id
      * @return mutations
      */
     public List<BackendAction> mutation(HugeType type, Id id) {
@@ -199,7 +204,8 @@ public class BackendMutation {
 
     /**
      * Whether mutation contains entry and action
-     * @param entry entry
+     *
+     * @param entry  entry
      * @param action action
      * @return true if exist, otherwise false
      */
@@ -218,12 +224,13 @@ public class BackendMutation {
 
     /**
      * Whether mutation contains type and action
-     * @param type type
+     *
+     * @param type   type
      * @param action action
      * @return true if exist, otherwise false
      */
     public boolean contains(HugeType type, Action action) {
-        for (Iterator<BackendAction> i = this.updates.get(type); i.hasNext();) {
+        for (Iterator<BackendAction> i = this.updates.get(type); i.hasNext(); ) {
             BackendAction entry = i.next();
             if (entry.action() == action) {
                 return true;
@@ -234,6 +241,7 @@ public class BackendMutation {
 
     /**
      * Whether this mutation is empty
+     *
      * @return true if empty, otherwise false
      */
     public boolean isEmpty() {
@@ -242,6 +250,7 @@ public class BackendMutation {
 
     /**
      * Get size of mutations
+     *
      * @return size
      */
     public int size() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendProviderFactory.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendProviderFactory.java
index 6b804b74f..bcfb31e4f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendProviderFactory.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendProviderFactory.java
@@ -20,8 +20,6 @@ package org.apache.hugegraph.backend.store;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.memory.InMemoryDBStoreProvider;
@@ -29,6 +27,7 @@ import org.apache.hugegraph.backend.store.raft.RaftBackendStoreProvider;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class BackendProviderFactory {
 
@@ -83,7 +82,7 @@ public class BackendProviderFactory {
         return instance;
     }
 
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public static void register(String name, String classPath) {
         ClassLoader classLoader = BackendProviderFactory.class.getClassLoader();
         Class<?> clazz = null;
@@ -96,7 +95,7 @@ public class BackendProviderFactory {
         // Check subclass
         boolean subclass = BackendStoreProvider.class.isAssignableFrom(clazz);
         BackendException.check(subclass, "Class '%s' is not a subclass of " +
-                               "class BackendStoreProvider", classPath);
+                                         "class BackendStoreProvider", classPath);
 
         // Check exists
         BackendException.check(!providers.containsKey(name),
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendSessionPool.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendSessionPool.java
index c7e3411bd..521f44556 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendSessionPool.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendSessionPool.java
@@ -23,11 +23,10 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.commons.lang3.tuple.Pair;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class BackendSessionPool {
 
@@ -47,7 +46,7 @@ public abstract class BackendSessionPool {
         this.sessionCount = new AtomicInteger(0);
         this.sessions = new ConcurrentHashMap<>();
         this.reconnectDetectInterval = this.config.get(
-                                       CoreOptions.STORE_CONN_DETECT_INTERVAL);
+                CoreOptions.STORE_CONN_DETECT_INTERVAL);
     }
 
     public HugeConfig config() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStore.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStore.java
index 20e5441c6..5c05e37c5 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStore.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStore.java
@@ -106,7 +106,7 @@ public interface BackendStore {
         }
 
         E.checkState(counter != 0L, "Please check whether '%s' is OK",
-                      this.provider().type());
+                     this.provider().type());
 
         E.checkState(counter == expect, "'%s' is busy please try again",
                      this.provider().type());
@@ -179,6 +179,11 @@ public interface BackendStore {
     }
 
     enum TxState {
-        BEGIN, COMMITTING, COMMITT_FAIL, ROLLBACKING, ROLLBACK_FAIL, CLEAN
+        BEGIN,
+        COMMITTING,
+        COMMITT_FAIL,
+        ROLLBACKING,
+        ROLLBACK_FAIL,
+        CLEAN
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreInfo.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreInfo.java
index 5f3c3f25c..f489e9572 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreInfo.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreInfo.java
@@ -18,9 +18,8 @@
 package org.apache.hugegraph.backend.store;
 
 import org.apache.hugegraph.config.HugeConfig;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class BackendStoreInfo {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreProvider.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreProvider.java
index 1d2b1bfae..44e58c228 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreProvider.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendStoreProvider.java
@@ -17,11 +17,12 @@
 
 package org.apache.hugegraph.backend.store;
 
-import com.alipay.remoting.rpc.RpcServer;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.event.EventHub;
 import org.apache.hugegraph.event.EventListener;
 
+import com.alipay.remoting.rpc.RpcServer;
+
 public interface BackendStoreProvider {
 
     String SCHEMA_STORE = "m";
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendTable.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendTable.java
index b8e6de1f1..a9ee4b5c7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendTable.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/BackendTable.java
@@ -280,8 +280,8 @@ public abstract class BackendTable<Session extends BackendSession, Entry> {
 
                 assert count > 1;
                 byte[] each = align(new BigInteger(1, subtract(end, start))
-                                        .divide(BigInteger.valueOf(count))
-                                        .toByteArray(),
+                                            .divide(BigInteger.valueOf(count))
+                                            .toByteArray(),
                                     length);
                 byte[] offset = start;
                 byte[] last = offset;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/TableDefine.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/TableDefine.java
index f926119d0..aae2793b9 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/TableDefine.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/TableDefine.java
@@ -26,6 +26,7 @@ import java.util.Set;
 
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.InsertionOrderUtil;
+
 import com.google.common.collect.ImmutableMap;
 
 public class TableDefine {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStore.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStore.java
index 85a3d49ee..c48274974 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStore.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStore.java
@@ -53,7 +53,7 @@ import org.slf4j.Logger;
  * 2.append/subtract edge-property
  */
 public abstract class InMemoryDBStore
-                extends AbstractBackendStore<BackendSession> {
+        extends AbstractBackendStore<BackendSession> {
 
     private static final Logger LOG = Log.logger(InMemoryDBStore.class);
 
@@ -125,7 +125,7 @@ public abstract class InMemoryDBStore
 
     @Override
     public void mutate(BackendMutation mutation) {
-        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext();) {
+        for (Iterator<BackendAction> it = mutation.mutation(); it.hasNext(); ) {
             this.mutate(it.next());
         }
     }
@@ -229,7 +229,7 @@ public abstract class InMemoryDBStore
     @Override
     public void rollbackTx() {
         throw new UnsupportedOperationException(
-                  "Unsupported rollback operation by InMemoryDBStore");
+                "Unsupported rollback operation by InMemoryDBStore");
     }
 
     @Override
@@ -340,19 +340,19 @@ public abstract class InMemoryDBStore
         @Override
         public Id nextId(HugeType type) {
             throw new UnsupportedOperationException(
-                      "InMemoryGraphStore.nextId()");
+                    "InMemoryGraphStore.nextId()");
         }
 
         @Override
         public void increaseCounter(HugeType type, long num) {
             throw new UnsupportedOperationException(
-                      "InMemoryGraphStore.increaseCounter()");
+                    "InMemoryGraphStore.increaseCounter()");
         }
 
         @Override
         public long getCounter(HugeType type) {
             throw new UnsupportedOperationException(
-                      "InMemoryGraphStore.getCounter()");
+                    "InMemoryGraphStore.getCounter()");
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStoreProvider.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStoreProvider.java
index d3460e554..aaf8e4700 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStoreProvider.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBStoreProvider.java
@@ -22,11 +22,11 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.hugegraph.backend.store.AbstractBackendStoreProvider;
 import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.util.Events;
 import org.apache.hugegraph.backend.store.memory.InMemoryDBStore.InMemoryGraphStore;
 import org.apache.hugegraph.backend.store.memory.InMemoryDBStore.InMemorySchemaStore;
 import org.apache.hugegraph.backend.store.memory.InMemoryDBStore.InMemorySystemStore;
 import org.apache.hugegraph.config.HugeConfig;
+import org.apache.hugegraph.util.Events;
 
 public class InMemoryDBStoreProvider extends AbstractBackendStoreProvider {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTable.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTable.java
index 1a6b3cef0..fb6ef7c02 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTable.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTable.java
@@ -27,15 +27,6 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.backend.serializer.TextBackendEntry;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendSession;
-import org.apache.hugegraph.backend.store.BackendTable;
-import org.apache.hugegraph.backend.store.Shard;
-import org.apache.hugegraph.exception.NotSupportException;
-import org.apache.hugegraph.type.HugeType;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.backend.query.Aggregate;
 import org.apache.hugegraph.backend.query.Aggregate.AggregateFunc;
 import org.apache.hugegraph.backend.query.Condition;
@@ -44,14 +35,23 @@ import org.apache.hugegraph.backend.query.IdPrefixQuery;
 import org.apache.hugegraph.backend.query.IdRangeQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
+import org.apache.hugegraph.backend.serializer.TextBackendEntry;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendSession;
+import org.apache.hugegraph.backend.store.BackendTable;
+import org.apache.hugegraph.backend.store.Shard;
+import org.apache.hugegraph.exception.NotSupportException;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 
 public class InMemoryDBTable extends BackendTable<BackendSession,
-                                                  TextBackendEntry> {
+        TextBackendEntry> {
 
     private static final Logger LOG = Log.logger(InMemoryDBTable.class);
 
@@ -260,8 +260,8 @@ public class InMemoryDBTable extends BackendTable<BackendSession,
     }
 
     protected Map<Id, BackendEntry> queryByFilter(
-                                    Collection<Condition> conditions,
-                                    Map<Id, BackendEntry> entries) {
+            Collection<Condition> conditions,
+            Map<Id, BackendEntry> entries) {
         assert conditions.size() > 0;
 
         Map<Id, BackendEntry> rs = new HashMap<>();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTables.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTables.java
index e3ea17179..0fdd36f09 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTables.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryDBTables.java
@@ -32,23 +32,24 @@ import java.util.concurrent.ConcurrentSkipListMap;
 import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.backend.serializer.TextBackendEntry;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
-import org.apache.hugegraph.backend.store.BackendSession;
-import org.apache.hugegraph.structure.HugeIndex;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.Condition.RangeConditions;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
+import org.apache.hugegraph.backend.serializer.TextBackendEntry;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendEntry.BackendColumn;
+import org.apache.hugegraph.backend.store.BackendSession;
 import org.apache.hugegraph.iterator.ExtendableIterator;
+import org.apache.hugegraph.structure.HugeIndex;
+import org.apache.hugegraph.type.HugeType;
+import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.NumericUtil;
+
 import com.google.common.collect.ImmutableList;
 
 public class InMemoryDBTables {
@@ -103,18 +104,18 @@ public class InMemoryDBTables {
 
         @Override
         protected Map<Id, BackendEntry> queryById(
-                                        Collection<Id> ids,
-                                        Map<Id, BackendEntry> entries) {
+                Collection<Id> ids,
+                Map<Id, BackendEntry> entries) {
             // Query edge(in a vertex) by id
             return this.queryEdgeById(ids, false, entries);
         }
 
         @Override
         protected Map<Id, BackendEntry> queryByIdPrefix(
-                                        Id start,
-                                        boolean inclusiveStart,
-                                        Id prefix,
-                                        Map<Id, BackendEntry> entries) {
+                Id start,
+                boolean inclusiveStart,
+                Id prefix,
+                Map<Id, BackendEntry> entries) {
             // Query edge(in a vertex) by v-id + column-name-prefix
             BackendEntry value = this.getEntryById(start, entries);
             if (value == null) {
@@ -145,11 +146,11 @@ public class InMemoryDBTables {
 
         @Override
         protected Map<Id, BackendEntry> queryByIdRange(
-                                        Id start,
-                                        boolean inclusiveStart,
-                                        Id end,
-                                        boolean inclusiveEnd,
-                                        Map<Id, BackendEntry> entries) {
+                Id start,
+                boolean inclusiveStart,
+                Id end,
+                boolean inclusiveEnd,
+                Map<Id, BackendEntry> entries) {
             BackendEntry value = this.getEntryById(start, entries);
             if (value == null) {
                 return Collections.emptyMap();
@@ -178,8 +179,8 @@ public class InMemoryDBTables {
         }
 
         private Map<Id, BackendEntry> queryEdgeById(
-                                      Collection<Id> ids, boolean prefix,
-                                      Map<Id, BackendEntry> entries) {
+                Collection<Id> ids, boolean prefix,
+                Map<Id, BackendEntry> entries) {
             assert ids.size() > 0;
             Map<Id, BackendEntry> rs = InsertionOrderUtil.newMap();
 
@@ -195,7 +196,7 @@ public class InMemoryDBTables {
                     } else if ((!prefix && entry.contains(column)) ||
                                (prefix && entry.containsPrefix(column))) {
                         BackendEntry edges = new TextBackendEntry(
-                                                 HugeType.VERTEX, entry.id());
+                                HugeType.VERTEX, entry.id());
                         if (prefix) {
                             // Some edges with specified prefix in the vertex
                             edges.columns(entry.columnsWithPrefix(column));
@@ -229,8 +230,8 @@ public class InMemoryDBTables {
 
         @Override
         protected Map<Id, BackendEntry> queryByFilter(
-                                        Collection<Condition> conditions,
-                                        Map<Id, BackendEntry> entries) {
+                Collection<Condition> conditions,
+                Map<Id, BackendEntry> entries) {
             if (conditions.isEmpty()) {
                 return entries;
             }
@@ -405,7 +406,7 @@ public class InMemoryDBTables {
             E.checkState(indexLabel != null, "Expect index label");
 
             Iterator<Entry<Id, BackendEntry>> iter;
-            for (iter = this.store().entrySet().iterator(); iter.hasNext();) {
+            for (iter = this.store().entrySet().iterator(); iter.hasNext(); ) {
                 Entry<Id, BackendEntry> e = iter.next();
                 // Delete if prefix with index label
                 if (e.getKey().asString().startsWith(indexLabel)) {
@@ -535,7 +536,7 @@ public class InMemoryDBTables {
             SortedMap<Id, BackendEntry> subStore;
             subStore = this.store().subMap(min, max);
             Iterator<Entry<Id, BackendEntry>> iter;
-            for (iter = subStore.entrySet().iterator(); iter.hasNext();) {
+            for (iter = subStore.entrySet().iterator(); iter.hasNext(); ) {
                 iter.next();
                 // Delete if prefix with index label
                 iter.remove();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryMetrics.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryMetrics.java
index 962545685..9e7caa38e 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryMetrics.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/memory/InMemoryMetrics.java
@@ -20,6 +20,7 @@ package org.apache.hugegraph.backend.store.memory;
 import java.util.Map;
 
 import org.apache.hugegraph.backend.store.BackendMetrics;
+
 import com.google.common.collect.ImmutableMap;
 
 public class InMemoryMetrics implements BackendMetrics {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStore.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStore.java
index 1f92cdb0b..bf89c6b17 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStore.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStore.java
@@ -22,11 +22,6 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.function.Function;
 
-import org.slf4j.Logger;
-
-import com.alipay.sofa.jraft.Status;
-import com.alipay.sofa.jraft.closure.ReadIndexClosure;
-import com.alipay.sofa.jraft.util.BytesUtil;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.store.BackendEntry;
@@ -41,6 +36,11 @@ import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.alipay.sofa.jraft.Status;
+import com.alipay.sofa.jraft.closure.ReadIndexClosure;
+import com.alipay.sofa.jraft.util.BytesUtil;
 
 public class RaftBackendStore implements BackendStore {
 
@@ -149,13 +149,13 @@ public class RaftBackendStore implements BackendStore {
     @SuppressWarnings("unchecked")
     public Iterator<BackendEntry> query(Query query) {
         return (Iterator<BackendEntry>)
-               this.queryByRaft(query, o -> this.store.query(query));
+                this.queryByRaft(query, o -> this.store.query(query));
     }
 
     @Override
     public Number queryNumber(Query query) {
         return (Number)
-               this.queryByRaft(query, o -> this.store.queryNumber(query));
+                this.queryByRaft(query, o -> this.store.queryNumber(query));
     }
 
     @Override
@@ -231,8 +231,8 @@ public class RaftBackendStore implements BackendStore {
                     future.complete(status, () -> func.apply(query));
                 } else {
                     future.failure(status, new BackendException(
-                                           "Failed to do raft read-index: %s",
-                                           status));
+                            "Failed to do raft read-index: %s",
+                            status));
                 }
             }
         };
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStoreProvider.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStoreProvider.java
index 32688da6c..ecdff19bd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStoreProvider.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftBackendStoreProvider.java
@@ -20,9 +20,6 @@ package org.apache.hugegraph.backend.store.raft;
 import java.util.Set;
 import java.util.concurrent.Future;
 
-import org.slf4j.Logger;
-
-import com.alipay.remoting.rpc.RpcServer;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.store.BackendStore;
@@ -35,6 +32,9 @@ import org.apache.hugegraph.event.EventListener;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Events;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.alipay.remoting.rpc.RpcServer;
 import com.google.common.collect.ImmutableSet;
 
 public class RaftBackendStoreProvider implements BackendStoreProvider {
@@ -47,6 +47,7 @@ public class RaftBackendStoreProvider implements BackendStoreProvider {
     private RaftBackendStore schemaStore;
     private RaftBackendStore graphStore;
     private RaftBackendStore systemStore;
+
     public RaftBackendStoreProvider(HugeGraphParams params,
                                     BackendStoreProvider provider) {
         this.provider = provider;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftClosure.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftClosure.java
index 2f9479e13..bd4e45da4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftClosure.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftClosure.java
@@ -23,12 +23,12 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.function.Supplier;
 
+import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.Closure;
 import com.alipay.sofa.jraft.Status;
-import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.util.Log;
 
 public class RaftClosure<T> implements Closure {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftContext.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftContext.java
index 852b56423..a70cd3022 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftContext.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftContext.java
@@ -184,11 +184,11 @@ public final class RaftContext {
         return this.raftNode;
     }
 
-    protected RpcServer rpcServer() {
+    RpcServer rpcServer() {
         return this.raftRpcServer;
     }
 
-    protected RpcForwarder rpcForwarder() {
+    RpcForwarder rpcForwarder() {
         return this.rpcForwarder;
     }
 
@@ -216,7 +216,7 @@ public final class RaftContext {
         }
     }
 
-    protected RaftBackendStore[] stores() {
+    RaftBackendStore[] stores() {
         return this.stores;
     }
 
@@ -233,13 +233,13 @@ public final class RaftContext {
         NodeOptions nodeOptions = new NodeOptions();
         nodeOptions.setEnableMetrics(false);
         nodeOptions.setRpcProcessorThreadPoolSize(
-                    config.get(CoreOptions.RAFT_RPC_THREADS));
+                config.get(CoreOptions.RAFT_RPC_THREADS));
         nodeOptions.setRpcConnectTimeoutMs(
-                    config.get(CoreOptions.RAFT_RPC_CONNECT_TIMEOUT));
+                config.get(CoreOptions.RAFT_RPC_CONNECT_TIMEOUT));
         nodeOptions.setRpcDefaultTimeout(
-                    1000 * config.get(CoreOptions.RAFT_RPC_TIMEOUT));
+                1000 * config.get(CoreOptions.RAFT_RPC_TIMEOUT));
         nodeOptions.setRpcInstallSnapshotTimeout(
-                    1000 * config.get(CoreOptions.RAFT_INSTALL_SNAPSHOT_TIMEOUT));
+                1000 * config.get(CoreOptions.RAFT_INSTALL_SNAPSHOT_TIMEOUT));
 
         int electionTimeout = config.get(CoreOptions.RAFT_ELECTION_TIMEOUT);
         nodeOptions.setElectionTimeoutMs(electionTimeout);
@@ -269,27 +269,27 @@ public final class RaftContext {
          */
         raftOptions.setApplyBatch(config.get(CoreOptions.RAFT_APPLY_BATCH));
         raftOptions.setDisruptorBufferSize(
-                    config.get(CoreOptions.RAFT_QUEUE_SIZE));
+                config.get(CoreOptions.RAFT_QUEUE_SIZE));
         raftOptions.setDisruptorPublishEventWaitTimeoutSecs(
-                    config.get(CoreOptions.RAFT_QUEUE_PUBLISH_TIMEOUT));
+                config.get(CoreOptions.RAFT_QUEUE_PUBLISH_TIMEOUT));
         raftOptions.setReplicatorPipeline(
-                    config.get(CoreOptions.RAFT_REPLICATOR_PIPELINE));
+                config.get(CoreOptions.RAFT_REPLICATOR_PIPELINE));
         raftOptions.setOpenStatistics(false);
         raftOptions.setReadOnlyOptions(
-                    ReadOnlyOption.valueOf(
-                    config.get(CoreOptions.RAFT_READ_STRATEGY)));
+                ReadOnlyOption.valueOf(
+                        config.get(CoreOptions.RAFT_READ_STRATEGY)));
 
         return nodeOptions;
     }
 
-    protected void clearCache() {
+    void clearCache() {
         // Just choose two representatives used to represent schema and graph
         this.notifyCache(Cache.ACTION_CLEAR, HugeType.VERTEX_LABEL, null);
         this.notifyCache(Cache.ACTION_CLEAR, HugeType.VERTEX, null);
     }
 
-    protected void updateCacheIfNeeded(BackendMutation mutation,
-                                       boolean forwarded) {
+    void updateCacheIfNeeded(BackendMutation mutation,
+                             boolean forwarded) {
         // Update cache only when graph run in general mode
         if (this.graphMode() != GraphMode.NONE) {
             return;
@@ -317,7 +317,7 @@ public final class RaftContext {
         }
     }
 
-    protected void notifyCache(String action, HugeType type, List<Id> ids) {
+    private void notifyCache(String action, HugeType type, List<Id> ids) {
         EventHub eventHub;
         if (type.isGraph()) {
             eventHub = this.params.graphEventHub();
@@ -373,18 +373,18 @@ public final class RaftContext {
     @SuppressWarnings("unused")
     private RpcServer initAndStartRpcServer() {
         Integer lowWaterMark = this.config().get(
-                               CoreOptions.RAFT_RPC_BUF_LOW_WATER_MARK);
+                CoreOptions.RAFT_RPC_BUF_LOW_WATER_MARK);
         System.setProperty("bolt.channel_write_buf_low_water_mark",
                            String.valueOf(lowWaterMark));
         Integer highWaterMark = this.config().get(
-                                CoreOptions.RAFT_RPC_BUF_HIGH_WATER_MARK);
+                CoreOptions.RAFT_RPC_BUF_HIGH_WATER_MARK);
         System.setProperty("bolt.channel_write_buf_high_water_mark",
                            String.valueOf(highWaterMark));
 
         PeerId endpoint = this.endpoint();
         NodeManager.getInstance().addAddress(endpoint.getEndpoint());
         RpcServer rpcServer = RaftRpcServerFactory.createAndStartRaftRpcServer(
-                                                   endpoint.getEndpoint());
+                endpoint.getEndpoint());
         LOG.info("Raft-RPC server is started successfully");
         return rpcServer;
     }
@@ -392,11 +392,11 @@ public final class RaftContext {
     private RpcServer wrapRpcServer(com.alipay.remoting.rpc.RpcServer rpcServer) {
         // TODO: pass ServerOptions instead of CoreOptions, to share by graphs
         Integer lowWaterMark = this.config().get(
-                               CoreOptions.RAFT_RPC_BUF_LOW_WATER_MARK);
+                CoreOptions.RAFT_RPC_BUF_LOW_WATER_MARK);
         System.setProperty("bolt.channel_write_buf_low_water_mark",
                            String.valueOf(lowWaterMark));
         Integer highWaterMark = this.config().get(
-                                CoreOptions.RAFT_RPC_BUF_HIGH_WATER_MARK);
+                CoreOptions.RAFT_RPC_BUF_HIGH_WATER_MARK);
         System.setProperty("bolt.channel_write_buf_high_water_mark",
                            String.valueOf(highWaterMark));
 
@@ -439,7 +439,7 @@ public final class RaftContext {
     private ExecutorService createBackendExecutor(int threads) {
         String name = "store-backend-executor";
         RejectedExecutionHandler handler =
-                                 new ThreadPoolExecutor.CallerRunsPolicy();
+                new ThreadPoolExecutor.CallerRunsPolicy();
         return newPool(threads, threads, name, handler);
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftException.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftException.java
index cce4db182..85e6915bf 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftException.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftException.java
@@ -45,7 +45,7 @@ public class RaftException extends HugeException {
 
     public static final void check(boolean expression,
                                    String message, Object... args)
-                                   throws RaftException {
+            throws RaftException {
         if (!expression) {
             throw new RaftException(message, args);
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftGroupManagerImpl.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftGroupManagerImpl.java
index ee1e32870..0f231d734 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftGroupManagerImpl.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftGroupManagerImpl.java
@@ -20,21 +20,19 @@ package org.apache.hugegraph.backend.store.raft;
 import java.util.List;
 import java.util.stream.Collectors;
 
-import com.alipay.sofa.jraft.Node;
-import com.alipay.sofa.jraft.Status;
-import com.alipay.sofa.jraft.entity.PeerId;
-import org.apache.hugegraph.backend.store.raft.rpc.RpcForwarder;
 import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.AddPeerRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.ListPeersRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.ListPeersResponse;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.RemovePeerRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.SetLeaderRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.SetLeaderResponse;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.AddPeerRequest;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.AddPeerResponse;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.RemovePeerRequest;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.RemovePeerResponse;
-
+import org.apache.hugegraph.backend.store.raft.rpc.RpcForwarder;
 import org.apache.hugegraph.util.E;
+
+import com.alipay.sofa.jraft.Node;
+import com.alipay.sofa.jraft.Status;
+import com.alipay.sofa.jraft.entity.PeerId;
 import com.google.protobuf.Message;
 
 public class RaftGroupManagerImpl implements RaftGroupManager {
@@ -87,8 +85,8 @@ public class RaftGroupManagerImpl implements RaftGroupManager {
         Status status = this.raftNode.node().transferLeadershipTo(peerId);
         if (!status.isOk()) {
             throw new BackendException(
-                      "Failed to transfer leader to '%s', raft error: %s",
-                      endpoint, status.getErrorMsg());
+                    "Failed to transfer leader to '%s', raft error: %s",
+                    endpoint, status.getErrorMsg());
         }
         return peerId.toString();
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftNode.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftNode.java
index 6f703f5c5..a8e07b411 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftNode.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftNode.java
@@ -24,6 +24,9 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.util.LZ4Util;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.Node;
@@ -37,9 +40,6 @@ import com.alipay.sofa.jraft.error.RaftError;
 import com.alipay.sofa.jraft.option.NodeOptions;
 import com.alipay.sofa.jraft.rpc.RpcServer;
 import com.alipay.sofa.jraft.util.BytesUtil;
-import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.util.LZ4Util;
-import org.apache.hugegraph.util.Log;
 
 public final class RaftNode {
 
@@ -69,11 +69,11 @@ public final class RaftNode {
         this.busyCounter = new AtomicInteger();
     }
 
-    protected RaftContext context() {
+    private RaftContext context() {
         return this.context;
     }
 
-    protected Node node() {
+    Node node() {
         assert this.node != null;
         return this.node;
     }
@@ -105,7 +105,7 @@ public final class RaftNode {
                 this.raftGroupService.join();
             } catch (final InterruptedException e) {
                 throw new RaftException(
-                          "Interrupted while shutdown raftGroupService");
+                        "Interrupted while shutdown raftGroupService");
             }
         }
     }
@@ -147,7 +147,7 @@ public final class RaftNode {
     private void submitCommand(StoreCommand command, RaftStoreClosure future) {
         // Wait leader elected
         LeaderInfo leaderInfo = this.waitLeaderElected(
-                                RaftContext.WAIT_LEADER_TIMEOUT);
+                RaftContext.WAIT_LEADER_TIMEOUT);
         // If myself is not leader, forward to the leader
         if (!leaderInfo.selfIsLeader) {
             this.context.rpcForwarder().forwardToLeader(leaderInfo.leaderId,
@@ -171,7 +171,7 @@ public final class RaftNode {
         this.node.apply(task);
     }
 
-    protected LeaderInfo waitLeaderElected(int timeout) {
+    LeaderInfo waitLeaderElected(int timeout) {
         String group = this.context.group();
         LeaderInfo leaderInfo = this.leaderInfo.get();
         if (leaderInfo.leaderId != null) {
@@ -189,8 +189,8 @@ public final class RaftNode {
             long consumedTime = System.currentTimeMillis() - beginTime;
             if (timeout > 0 && consumedTime >= timeout) {
                 throw new BackendException(
-                          "Waiting for raft group '%s' election timeout(%sms)",
-                          group, consumedTime);
+                        "Waiting for raft group '%s' election timeout(%sms)",
+                        group, consumedTime);
             }
             leaderInfo = this.leaderInfo.get();
             assert leaderInfo != null;
@@ -199,7 +199,7 @@ public final class RaftNode {
         return leaderInfo;
     }
 
-    protected void waitRaftLogSynced(int timeout) {
+    void waitRaftLogSynced(int timeout) {
         String group = this.context.group();
         LOG.info("Waiting for raft group '{}' log synced", group);
         long beginTime = System.currentTimeMillis();
@@ -219,8 +219,8 @@ public final class RaftNode {
             long consumedTime = System.currentTimeMillis() - beginTime;
             if (timeout > 0 && consumedTime >= timeout) {
                 throw new BackendException(
-                          "Waiting for raft group '%s' log synced timeout(%sms)",
-                          group, consumedTime);
+                        "Waiting for raft group '%s' log synced timeout(%sms)",
+                        group, consumedTime);
             }
         }
         LOG.info("Waited for raft group '{}' log synced successfully", group);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftResult.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftResult.java
index ad9c39702..74f8f8b48 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftResult.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/RaftResult.java
@@ -19,9 +19,10 @@ package org.apache.hugegraph.backend.store.raft;
 
 import java.util.function.Supplier;
 
-import com.alipay.sofa.jraft.Status;
 import org.apache.hugegraph.util.E;
 
+import com.alipay.sofa.jraft.Status;
+
 public final class RaftResult<T> {
 
     private final Status status;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSerializer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSerializer.java
index 8c6c4fc7d..69937737d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSerializer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSerializer.java
@@ -68,7 +68,7 @@ public final class StoreSerializer {
         // write mutation size
         buffer.writeVInt(mutation.size());
         for (Iterator<BackendAction> items = mutation.mutation();
-             items.hasNext();) {
+             items.hasNext(); ) {
             BackendAction item = items.next();
             // write Action
             buffer.write(item.action().code());
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSnapshotFile.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSnapshotFile.java
index f59899fb4..dd9e6b891 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSnapshotFile.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreSnapshotFile.java
@@ -218,7 +218,7 @@ public class StoreSnapshotFile {
                      archiveFile, parentPath, (end - begin) / 1000.0F);
         } catch (Throwable e) {
             throw new RaftException(
-                "Failed to decompress snapshot, zip=%s", e, archiveFile);
+                    "Failed to decompress snapshot, zip=%s", e, archiveFile);
         }
 
         if (meta.hasChecksum()) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreStateMachine.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreStateMachine.java
index 81cb1af09..df54a8276 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreStateMachine.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/StoreStateMachine.java
@@ -23,6 +23,16 @@ import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 
+import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.backend.serializer.BytesBuffer;
+import org.apache.hugegraph.backend.store.BackendMutation;
+import org.apache.hugegraph.backend.store.BackendStore;
+import org.apache.hugegraph.backend.store.raft.RaftBackendStore.IncrCounter;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreAction;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreType;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.LZ4Util;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.Closure;
@@ -35,16 +45,6 @@ import com.alipay.sofa.jraft.error.RaftError;
 import com.alipay.sofa.jraft.error.RaftException;
 import com.alipay.sofa.jraft.storage.snapshot.SnapshotReader;
 import com.alipay.sofa.jraft.storage.snapshot.SnapshotWriter;
-import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.backend.serializer.BytesBuffer;
-import org.apache.hugegraph.backend.store.BackendMutation;
-import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.backend.store.raft.RaftBackendStore.IncrCounter;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreAction;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreType;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.LZ4Util;
-import org.apache.hugegraph.util.Log;
 
 public final class StoreStateMachine extends StateMachineAdapter {
 
@@ -165,7 +165,7 @@ public final class StoreStateMachine extends StateMachineAdapter {
                 break;
             case COMMIT_TX:
                 List<BackendMutation> mutations = StoreSerializer.readMutations(
-                                                  buffer);
+                        buffer);
                 // RaftBackendStore doesn't write raft log for beginTx
                 store.beginTx();
                 for (BackendMutation mutation : mutations) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/CompressStrategyManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/CompressStrategyManager.java
index 640807c9d..2e17c456d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/CompressStrategyManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/CompressStrategyManager.java
@@ -56,10 +56,10 @@ public class CompressStrategyManager {
         // add parallel compress strategy
         if (compressStrategies[PARALLEL_STRATEGY] == null) {
             CompressStrategy compressStrategy = new ParallelCompressStrategy(
-                config.get(CoreOptions.RAFT_SNAPSHOT_COMPRESS_THREADS),
-                config.get(CoreOptions.RAFT_SNAPSHOT_DECOMPRESS_THREADS));
+                    config.get(CoreOptions.RAFT_SNAPSHOT_COMPRESS_THREADS),
+                    config.get(CoreOptions.RAFT_SNAPSHOT_DECOMPRESS_THREADS));
             CompressStrategyManager.addCompressStrategy(
-                CompressStrategyManager.PARALLEL_STRATEGY, compressStrategy);
+                    CompressStrategyManager.PARALLEL_STRATEGY, compressStrategy);
             DEFAULT_STRATEGY = PARALLEL_STRATEGY;
         }
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/ParallelCompressStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/ParallelCompressStrategy.java
index 040bebb68..09b2b3e9e 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/ParallelCompressStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/compress/ParallelCompressStrategy.java
@@ -104,10 +104,10 @@ public class ParallelCompressStrategy implements CompressStrategy {
         FileUtils.forceMkdir(zipFile.getParentFile());
 
         ExecutorService compressExecutor =
-            newFixedPool(compressThreads, compressThreads, "raft-snapshot-compress-executor",
-                         new ThreadPoolExecutor.CallerRunsPolicy());
+                newFixedPool(compressThreads, compressThreads, "raft-snapshot-compress-executor",
+                             new ThreadPoolExecutor.CallerRunsPolicy());
         ZipArchiveScatterOutputStream scatterOutput =
-            new ZipArchiveScatterOutputStream(compressExecutor);
+                new ZipArchiveScatterOutputStream(compressExecutor);
         compressDirectoryToZipFile(rootFile, scatterOutput, sourceDir, ZipEntry.DEFLATED);
 
         try (FileOutputStream fos = new FileOutputStream(zipFile);
@@ -127,9 +127,9 @@ public class ParallelCompressStrategy implements CompressStrategy {
                               Checksum checksum) throws Throwable {
         LOG.info("Start to decompress snapshot in parallel mode");
         ExecutorService decompressExecutor =
-            newFixedPool(decompressThreads, decompressThreads,
-                         "raft-snapshot-decompress-executor",
-                         new ThreadPoolExecutor.CallerRunsPolicy());
+                newFixedPool(decompressThreads, decompressThreads,
+                             "raft-snapshot-decompress-executor",
+                             new ThreadPoolExecutor.CallerRunsPolicy());
         // compute the checksum in a single thread
         Future<Boolean> checksumFuture = decompressExecutor.submit(() -> {
             computeZipFileChecksumValue(sourceZipFile, checksum);
@@ -209,7 +209,7 @@ public class ParallelCompressStrategy implements CompressStrategy {
         try (InputStream is = zipFile.getInputStream(entry);
              BufferedInputStream fis = new BufferedInputStream(is);
              BufferedOutputStream bos =
-                 new BufferedOutputStream(Files.newOutputStream(targetFile.toPath()))) {
+                     new BufferedOutputStream(Files.newOutputStream(targetFile.toPath()))) {
             IOUtils.copy(fis, bos);
         }
     }
@@ -219,7 +219,7 @@ public class ParallelCompressStrategy implements CompressStrategy {
      */
     private void computeZipFileChecksumValue(String zipPath, Checksum checksum) throws Exception {
         try (BufferedInputStream bis =
-                 new BufferedInputStream(Files.newInputStream(Paths.get(zipPath)));
+                     new BufferedInputStream(Files.newInputStream(Paths.get(zipPath)));
              CheckedInputStream cis = new CheckedInputStream(bis, checksum);
              ZipArchiveInputStream zis = new ZipArchiveInputStream(cis)) {
             // checksum is calculated in the process
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/AddPeerProcessor.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/AddPeerProcessor.java
index d1bdbf004..275de3fc2 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/AddPeerProcessor.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/AddPeerProcessor.java
@@ -17,19 +17,20 @@
 
 package org.apache.hugegraph.backend.store.raft.rpc;
 
-import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
-import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
-import com.google.protobuf.Message;
 import org.apache.hugegraph.backend.store.raft.RaftContext;
 import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.AddPeerRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.AddPeerResponse;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
+import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
+import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
+import com.google.protobuf.Message;
+
 public class AddPeerProcessor
-       extends RpcRequestProcessor<AddPeerRequest> {
+        extends RpcRequestProcessor<AddPeerRequest> {
 
     private static final Logger LOG = Log.logger(AddPeerProcessor.class);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/ListPeersProcessor.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/ListPeersProcessor.java
index 807092899..ebe96b7a7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/ListPeersProcessor.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/ListPeersProcessor.java
@@ -17,21 +17,21 @@
 
 package org.apache.hugegraph.backend.store.raft.rpc;
 
-import org.slf4j.Logger;
-
-import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
-import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
-import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
 import org.apache.hugegraph.backend.store.raft.RaftContext;
+import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.ListPeersRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.ListPeersResponse;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
+
+import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
+import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
 import com.google.common.collect.ImmutableList;
 import com.google.protobuf.Message;
 
 public class ListPeersProcessor
-       extends RpcRequestProcessor<ListPeersRequest> {
+        extends RpcRequestProcessor<ListPeersRequest> {
 
     private static final Logger LOG = Log.logger(ListPeersProcessor.class);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RemovePeerProcessor.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RemovePeerProcessor.java
index fd2ba2eac..31d10f41d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RemovePeerProcessor.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RemovePeerProcessor.java
@@ -17,19 +17,20 @@
 
 package org.apache.hugegraph.backend.store.raft.rpc;
 
-import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
-import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
-import com.google.protobuf.Message;
 import org.apache.hugegraph.backend.store.raft.RaftContext;
 import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.RemovePeerRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.RemovePeerResponse;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
+import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
+import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
+import com.google.protobuf.Message;
+
 public class RemovePeerProcessor
-       extends RpcRequestProcessor<RemovePeerRequest> {
+        extends RpcRequestProcessor<RemovePeerRequest> {
 
     private static final Logger LOG = Log.logger(RemovePeerProcessor.class);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RpcForwarder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RpcForwarder.java
index a9f9d8ee6..0944f5cc3 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RpcForwarder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/RpcForwarder.java
@@ -19,8 +19,16 @@ package org.apache.hugegraph.backend.store.raft.rpc;
 
 import java.util.concurrent.ExecutionException;
 
+import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.backend.store.raft.RaftClosure;
+import org.apache.hugegraph.backend.store.raft.RaftContext;
 import org.apache.hugegraph.backend.store.raft.RaftStoreClosure;
 import org.apache.hugegraph.backend.store.raft.StoreCommand;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandRequest;
+import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandResponse;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.Node;
@@ -31,14 +39,6 @@ import com.alipay.sofa.jraft.error.RaftError;
 import com.alipay.sofa.jraft.rpc.RaftClientService;
 import com.alipay.sofa.jraft.rpc.RpcResponseClosure;
 import com.alipay.sofa.jraft.util.Endpoint;
-import org.apache.hugegraph.backend.BackendException;
-import org.apache.hugegraph.backend.store.raft.RaftClosure;
-import org.apache.hugegraph.backend.store.raft.RaftContext;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandRequest;
-import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandResponse;
-import org.apache.hugegraph.util.E;
-import org.apache.hugegraph.util.Log;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Message;
 import com.google.protobuf.ZeroByteStringHelper;
@@ -77,10 +77,13 @@ public class RpcForwarder {
             public void setResponse(StoreCommandResponse response) {
                 if (response.getStatus()) {
                     LOG.debug("StoreCommandResponse status ok");
-                    // This code forwards the request to the Raft leader and considers the operation successful
+                    // This code forwards the request to the Raft leader and considers the
+                    // operation successful
                     // if it's forwarded successfully. It returns a RaftClosure because the calling
-                    // logic expects a RaftClosure result. Specifically, if the current instance is the Raft leader,
-                    // it executes the corresponding logic locally and notifies the calling logic asynchronously
+                    // logic expects a RaftClosure result. Specifically, if the current instance
+                    // is the Raft leader,
+                    // it executes the corresponding logic locally and notifies the calling logic
+                    // asynchronously
                     // via RaftClosure. Therefore, the result is returned as a RaftClosure here.
                     RaftClosure<Status> supplierFuture = new RaftClosure<>();
                     supplierFuture.complete(Status.OK());
@@ -90,10 +93,10 @@ public class RpcForwarder {
                     Status status = new Status(RaftError.UNKNOWN,
                                                "fowared request failed");
                     BackendException e = new BackendException(
-                                         "Current node isn't leader, leader " +
-                                         "is [%s], failed to forward request " +
-                                         "to leader: %s",
-                                         leaderId, response.getMessage());
+                            "Current node isn't leader, leader " +
+                            "is [%s], failed to forward request " +
+                            "to leader: %s",
+                            leaderId, response.getMessage());
                     future.failure(status, e);
                 }
             }
@@ -133,10 +136,10 @@ public class RpcForwarder {
                     Status status = new Status(RaftError.UNKNOWN,
                                                "fowared request failed");
                     BackendException e = new BackendException(
-                                         "Current node isn't leader, leader " +
-                                         "is [%s], failed to forward request " +
-                                         "to leader: %s",
-                                         leaderId, commonResponse.getMessage());
+                            "Current node isn't leader, leader " +
+                            "is [%s], failed to forward request " +
+                            "to leader: %s",
+                            leaderId, commonResponse.getMessage());
                     future.failure(status, e);
                 }
             }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/SetLeaderProcessor.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/SetLeaderProcessor.java
index d9fa36323..58589fe26 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/SetLeaderProcessor.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/SetLeaderProcessor.java
@@ -22,15 +22,15 @@ import org.apache.hugegraph.backend.store.raft.RaftGroupManager;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.CommonResponse;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.SetLeaderRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.SetLeaderResponse;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
 import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
-import org.apache.hugegraph.util.Log;
 import com.google.protobuf.Message;
 
 public class SetLeaderProcessor
-       extends RpcRequestProcessor<SetLeaderRequest> {
+        extends RpcRequestProcessor<SetLeaderRequest> {
 
     private static final Logger LOG = Log.logger(SetLeaderProcessor.class);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/StoreCommandProcessor.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/StoreCommandProcessor.java
index 8739c2269..e8863c512 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/StoreCommandProcessor.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/raft/rpc/StoreCommandProcessor.java
@@ -25,18 +25,18 @@ import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreAction;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandRequest;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreCommandResponse;
 import org.apache.hugegraph.backend.store.raft.rpc.RaftRequests.StoreType;
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
 import com.alipay.sofa.jraft.rpc.RpcRequestClosure;
 import com.alipay.sofa.jraft.rpc.RpcRequestProcessor;
-import org.apache.hugegraph.util.Log;
 import com.google.protobuf.Message;
 
 public class StoreCommandProcessor
-       extends RpcRequestProcessor<StoreCommandRequest> {
+        extends RpcRequestProcessor<StoreCommandRequest> {
 
     private static final Logger LOG = Log.logger(
-                                      StoreCommandProcessor.class);
+            StoreCommandProcessor.class);
 
     private final RaftContext context;
 
@@ -60,8 +60,8 @@ public class StoreCommandProcessor
             LOG.warn("Failed to process StoreCommandRequest: {}",
                      request.getAction(), e);
             StoreCommandResponse.Builder builder = StoreCommandResponse
-                                                   .newBuilder()
-                                                   .setStatus(false);
+                    .newBuilder()
+                    .setStatus(false);
             if (e.getMessage() != null) {
                 builder.setMessage(e.getMessage());
             }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
index 0729f4b80..f71c44acd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/store/ram/RamTable.java
@@ -75,8 +75,8 @@ public final class RamTable {
     private static final int NULL = 0;
 
     private static final Condition BOTH_COND = Condition.or(
-                         Condition.eq(HugeKeys.DIRECTION, Directions.OUT),
-                         Condition.eq(HugeKeys.DIRECTION, Directions.IN));
+            Condition.eq(HugeKeys.DIRECTION, Directions.OUT),
+            Condition.eq(HugeKeys.DIRECTION, Directions.IN));
 
     private final HugeGraph graph;
     private final long verticesCapacity;
@@ -145,7 +145,7 @@ public final class RamTable {
         File file = Paths.get(EXPORT_PATH, fileName).toFile();
         if (!file.exists() || !file.isFile() || !file.canRead()) {
             throw new IllegalArgumentException(String.format(
-                      "File '%s' does not existed or readable", fileName));
+                    "File '%s' does not existed or readable", fileName));
         }
         try (FileInputStream fis = new FileInputStream(file);
              BufferedInputStream bis = new BufferedInputStream(fis);
@@ -301,7 +301,7 @@ public final class RamTable {
         assert this.edgesSize() > 0;
 
         List<ConditionQuery> cqs = ConditionQueryFlatten.flatten(
-                                   (ConditionQuery) query);
+                (ConditionQuery) query);
         if (cqs.size() == 1) {
             ConditionQuery cq = cqs.get(0);
             return this.query(cq);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/AbstractTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/AbstractTransaction.java
index 5611a43e1..43393252d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/AbstractTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/AbstractTransaction.java
@@ -20,17 +20,15 @@ package org.apache.hugegraph.backend.tx;
 import java.util.Set;
 
 import org.apache.commons.lang3.StringUtils;
-import org.apache.hugegraph.backend.query.IdQuery;
-import org.apache.hugegraph.backend.query.Query;
-import org.apache.hugegraph.backend.query.QueryResults;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.Transaction;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.query.IdQuery;
+import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.serializer.AbstractSerializer;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.BackendEntryIterator;
@@ -47,6 +45,8 @@ import org.apache.hugegraph.type.define.GraphMode;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.collection.IdSet;
+import org.slf4j.Logger;
+
 import com.google.common.util.concurrent.RateLimiter;
 
 public abstract class AbstractTransaction implements Transaction {
@@ -192,8 +192,8 @@ public abstract class AbstractTransaction implements Transaction {
         BackendEntry entry = this.query(type, id);
         if (entry == null) {
             throw new NotFoundException(
-                      "Not found the %s entry with id '%s'",
-                      type.readableName(), id);
+                    "Not found the %s entry with id '%s'",
+                    type.readableName(), id);
         }
         return entry;
     }
@@ -387,7 +387,7 @@ public abstract class AbstractTransaction implements Transaction {
              */
             throw new BackendException("Failed to commit changes: %s(%s)",
                                        StringUtils.abbreviateMiddle(
-                                       e1.getMessage(), ".", 256),
+                                               e1.getMessage(), ".", 256),
                                        HugeException.rootCause(e1));
         }
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java
index 1670f7db9..ba2680f09 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java
@@ -32,15 +32,6 @@ import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import org.apache.commons.lang3.StringUtils;
-import org.apache.hugegraph.backend.page.PageIds;
-import org.apache.hugegraph.backend.page.PageState;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.task.EphemeralJobQueue;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
@@ -51,7 +42,9 @@ import org.apache.hugegraph.backend.page.IdHolder.BatchIdHolder;
 import org.apache.hugegraph.backend.page.IdHolder.FixedIdHolder;
 import org.apache.hugegraph.backend.page.IdHolder.PagingIdHolder;
 import org.apache.hugegraph.backend.page.IdHolderList;
+import org.apache.hugegraph.backend.page.PageIds;
 import org.apache.hugegraph.backend.page.PageInfo;
+import org.apache.hugegraph.backend.page.PageState;
 import org.apache.hugegraph.backend.page.SortByCountIdHolderList;
 import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.Condition.RangeConditions;
@@ -63,6 +56,8 @@ import org.apache.hugegraph.backend.query.ConditionQueryFlatten;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.serializer.AbstractSerializer;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.exception.NoIndexException;
@@ -81,6 +76,7 @@ import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.structure.HugeIndex.IdWithExpiredTime;
 import org.apache.hugegraph.structure.HugeProperty;
 import org.apache.hugegraph.structure.HugeVertex;
+import org.apache.hugegraph.task.EphemeralJobQueue;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Action;
 import org.apache.hugegraph.type.define.HugeKeys;
@@ -91,6 +87,10 @@ import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.LockUtil;
 import org.apache.hugegraph.util.LongEncoding;
 import org.apache.hugegraph.util.NumericUtil;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -111,7 +111,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
         final HugeConfig conf = graph.configuration();
         this.indexIntersectThresh =
-             conf.get(CoreOptions.QUERY_INDEX_INTERSECT_THRESHOLD);
+                conf.get(CoreOptions.QUERY_INDEX_INTERSECT_THRESHOLD);
     }
 
     protected void asyncRemoveIndexLeft(ConditionQuery query,
@@ -186,9 +186,10 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
     /**
      * Update index(user properties) of vertex or edge
-     * @param ilId      the id of index label
-     * @param element   the properties owner
-     * @param removed   remove or add index
+     *
+     * @param ilId    the id of index label
+     * @param element the properties owner
+     * @param removed remove or add index
      */
     protected void updateIndex(Id ilId, HugeElement element, boolean removed) {
         ISchemaTransaction schema = this.params().schemaTransaction();
@@ -242,7 +243,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
                              "Expect only one property in search index");
                 value = nnPropValues.get(0);
                 Set<String> words =
-                            this.segmentWords(propertyValueToString(value));
+                        this.segmentWords(propertyValueToString(value));
                 for (String word : words) {
                     this.updateIndex(indexLabel, word, element.id(),
                                      expiredTime, removed);
@@ -263,7 +264,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 } else {
                     for (int i = 0, n = nnPropValues.size(); i < n; i++) {
                         List<Object> prefixValues =
-                                     nnPropValues.subList(0, i + 1);
+                                nnPropValues.subList(0, i + 1);
                         value = ConditionQuery.concatValues(prefixValues);
                         this.updateIndex(indexLabel, value, element.id(),
                                          expiredTime, removed);
@@ -282,15 +283,15 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 // TODO: add lock for updating unique index
                 if (!removed && this.existUniqueValue(indexLabel, value, id)) {
                     throw new IllegalArgumentException(String.format(
-                              "Unique constraint %s conflict is found for %s",
-                              indexLabel, element));
+                            "Unique constraint %s conflict is found for %s",
+                            indexLabel, element));
                 }
                 this.updateIndex(indexLabel, value, element.id(),
                                  expiredTime, removed);
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown index type '%s'", indexLabel.indexType()));
+                        "Unknown index type '%s'", indexLabel.indexType()));
         }
     }
 
@@ -355,8 +356,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
      * Single index, an index involving only one column.
      * Joint indexes, join of single indexes, composite indexes or mixed
      * of single indexes and composite indexes.
+     *
      * @param query original condition query
-     * @return      converted id query
+     * @return converted id query
      */
     @Watched(prefix = "index")
     public IdHolderList queryIndex(ConditionQuery query) {
@@ -453,9 +455,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 PropertyKey propertyKey = this.graph().propertyKey(pkId);
                 if (propertyKey.olap()) {
                     throw new NotAllowException(
-                              "Not allowed to query by olap property key '%s'" +
-                              " when graph-read-mode is '%s'",
-                              propertyKey, this.graph().readMode());
+                            "Not allowed to query by olap property key '%s'" +
+                            " when graph-read-mode is '%s'",
+                            propertyKey, this.graph().readMode());
                 }
             }
         }
@@ -581,7 +583,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
             }
             assert this.indexIntersectThresh > 0; // default value is 1000
             Set<Id> ids = ((BatchIdHolder) holder).peekNext(
-                          this.indexIntersectThresh).ids();
+                    this.indexIntersectThresh).ids();
             if (ids.size() >= this.indexIntersectThresh) {
                 // Transform into filtering
                 filtering = true;
@@ -619,7 +621,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
         }
 
         ConditionQuery originConditionQuery =
-                       query.originConditionQuery();
+                query.originConditionQuery();
         if (originConditionQuery != null) {
             originConditionQuery.selectedIndexField(indexLabel.indexField());
         }
@@ -743,8 +745,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 schemaLabel = schema.getEdgeLabel(label);
             } else {
                 throw new AssertionError(String.format(
-                          "Unsupported index query type: %s",
-                          query.resultType()));
+                        "Unsupported index query type: %s",
+                        query.resultType()));
             }
             schemaLabels = ImmutableList.of(schemaLabel);
         } else {
@@ -755,8 +757,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 schemaLabels = schema.getEdgeLabels();
             } else {
                 throw new AssertionError(String.format(
-                          "Unsupported index query type: %s",
-                          query.resultType()));
+                        "Unsupported index query type: %s",
+                        query.resultType()));
             }
         }
 
@@ -773,8 +775,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
     /**
      * Collect matched IndexLabel(s) in a SchemaLabel for a query
+     *
      * @param schemaLabel find indexLabels of this schemaLabel
-     * @param query conditions container
+     * @param query       conditions container
      * @return MatchedLabel object contains schemaLabel and matched indexLabels
      */
     @Watched(prefix = "index")
@@ -917,8 +920,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     private static Set<IndexLabel> matchSingleOrCompositeIndex(
-                                   ConditionQuery query,
-                                   Set<IndexLabel> indexLabels) {
+            ConditionQuery query,
+            Set<IndexLabel> indexLabels) {
         if (query.hasNeqCondition()) {
             return ImmutableSet.of();
         }
@@ -958,8 +961,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
      * property-keys in query
      */
     private static Set<IndexLabel> matchJointIndexes(
-                                   ConditionQuery query,
-                                   Set<IndexLabel> indexLabels) {
+            ConditionQuery query,
+            Set<IndexLabel> indexLabels) {
         if (query.hasNeqCondition()) {
             return ImmutableSet.of();
         }
@@ -1015,8 +1018,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     private static Set<IndexLabel> matchRangeOrSearchIndexLabels(
-                                   ConditionQuery query,
-                                   Set<IndexLabel> indexLabels) {
+            ConditionQuery query,
+            Set<IndexLabel> indexLabels) {
         Set<IndexLabel> matchedIndexLabels = InsertionOrderUtil.newSet();
         for (Relation relation : query.userpropRelations()) {
             if (!relation.relation().isRangeType() &&
@@ -1098,11 +1101,12 @@ public class GraphIndexTransaction extends AbstractTransaction {
      * Traverse C(m, n) combinations of a list to find first matched
      * result combination and call back with the result.
      * TODO: move this method to common module.
-     * @param all list to contain all items for combination
-     * @param m m of C(m, n)
-     * @param n n of C(m, n)
+     *
+     * @param all     list to contain all items for combination
+     * @param m       m of C(m, n)
+     * @param n       n of C(m, n)
      * @param current current position in list
-     * @param result list to contains selected items
+     * @param result  list to contains selected items
      * @return true if matched items combination else false
      */
     private static <T> boolean cmn(List<T> all, int m, int n,
@@ -1140,10 +1144,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
         }
         // Not select current item, continue to select C(m-1, n)
         result.remove(index);
-        if (cmn(all, m - 1, n, current, result, callback)) {
-            return true;
-        }
-        return false;
+        return cmn(all, m - 1, n, current, result, callback);
     }
 
     private static boolean shouldRecordIndexValue(ConditionQuery query,
@@ -1154,8 +1155,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     private static IndexQueries constructJointSecondaryQueries(
-                                ConditionQuery query,
-                                List<IndexLabel> ils) {
+            ConditionQuery query,
+            List<IndexLabel> ils) {
         Set<IndexLabel> indexLabels = InsertionOrderUtil.newSet();
         indexLabels.addAll(ils);
         indexLabels = matchJointIndexes(query, indexLabels);
@@ -1241,8 +1242,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
             case RANGE_DOUBLE:
                 if (query.userpropConditions().size() > 2) {
                     throw new HugeException(
-                              "Range query has two conditions at most, " +
-                              "but got: %s", query.userpropConditions());
+                            "Range query has two conditions at most, " +
+                            "but got: %s", query.userpropConditions());
                 }
                 // Replace the query key with PROPERTY_VALUES, set number value
                 indexQuery = new ConditionQuery(indexType.type(), query);
@@ -1252,8 +1253,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
                     Relation r = (Relation) condition;
                     Number value = NumericUtil.convertToNumber(r.value());
                     Relation sys = new Condition.SyspropRelation(
-                                                 HugeKeys.FIELD_VALUES,
-                                                 r.relation(), value);
+                            HugeKeys.FIELD_VALUES,
+                            r.relation(), value);
                     condition = condition.replace(r, sys);
                     indexQuery.query(condition);
                 }
@@ -1263,13 +1264,13 @@ public class GraphIndexTransaction extends AbstractTransaction {
                 indexQuery = new ConditionQuery(type, query);
                 indexQuery.eq(HugeKeys.INDEX_LABEL_ID, indexLabel.id());
                 List<Condition> conditions = constructShardConditions(
-                                             query, indexLabel.indexFields(),
-                                             HugeKeys.FIELD_VALUES);
+                        query, indexLabel.indexFields(),
+                        HugeKeys.FIELD_VALUES);
                 indexQuery.query(conditions);
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown index type '%s'", indexType));
+                        "Unknown index type '%s'", indexType));
         }
 
         /*
@@ -1287,9 +1288,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     protected static List<Condition> constructShardConditions(
-                                     ConditionQuery query,
-                                     List<Id> fields,
-                                     HugeKeys key) {
+            ConditionQuery query,
+            List<Id> fields,
+            HugeKeys key) {
         List<Condition> conditions = new ArrayList<>(2);
         boolean hasRange = false;
         int processedCondCount = 0;
@@ -1380,9 +1381,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     private static Relation shardFieldValuesCondition(HugeKeys key,
-                                                                List<Object> prefixes,
-                                                                Object number,
-                                                                RelationType type) {
+                                                      List<Object> prefixes,
+                                                      Object number,
+                                                      RelationType type) {
         List<Object> values = new ArrayList<>(prefixes);
         String num = LongEncoding.encodeNumber(number);
         if (type == RelationType.LTE) {
@@ -1488,9 +1489,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
                                                      ConditionQuery query,
                                                      Id label) {
         String name = label == null ? "any label" : String.format("label '%s'",
-                      query.resultType().isVertex() ?
-                      graph.vertexLabel(label).name() :
-                      graph.edgeLabel(label).name());
+                                                                  query.resultType().isVertex() ?
+                                                                  graph.vertexLabel(label).name() :
+                                                                  graph.edgeLabel(label).name());
         List<String> mismatched = new ArrayList<>();
         if (query.hasSecondaryCondition()) {
             mismatched.add("secondary");
@@ -1619,7 +1620,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     private static class IndexQueries
-                   extends HashMap<IndexLabel, ConditionQuery> {
+            extends HashMap<IndexLabel, ConditionQuery> {
 
         private static final long serialVersionUID = 1400326138090922676L;
         private static final IndexQueries EMPTY = new IndexQueries(null);
@@ -1664,7 +1665,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
         }
 
         public Query asJointQuery() {
-            @SuppressWarnings({ "unchecked", "rawtypes" })
+            @SuppressWarnings({"unchecked", "rawtypes"})
             Collection<Query> queries = (Collection) this.values();
             return new JointQuery(this.rootQuery().resultType(),
                                   this.parentQuery, queries);
@@ -1713,7 +1714,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
     }
 
     public static class RemoveLeftIndexJob extends EphemeralJob<Long>
-                                           implements EphemeralJobQueue.Reduce<Long> {
+            implements EphemeralJobQueue.Reduce<Long> {
 
         private static final String REMOVE_LEFT_INDEX = "remove_left_index";
 
@@ -1772,7 +1773,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
             long rCount = 0;
             long sCount = 0;
-            for (ConditionQuery cq: ConditionQueryFlatten.flatten(query)) {
+            for (ConditionQuery cq : ConditionQueryFlatten.flatten(query)) {
                 // Process range index
                 rCount += this.processRangeIndexLeft(cq, element);
                 // Process secondary index or search index
@@ -1810,7 +1811,7 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
         private IndexLabel findMatchedIndexLabel(ConditionQuery query,
                                                  ConditionQuery.LeftIndex
-                                                 leftIndex) {
+                                                         leftIndex) {
             Set<MatchedIndex> matchedIndexes = this.tx.collectMatchedIndexes(query);
             for (MatchedIndex index : matchedIndexes) {
                 for (IndexLabel label : index.indexLabels()) {
@@ -1839,16 +1840,16 @@ public class GraphIndexTransaction extends AbstractTransaction {
                                              .map(PropertyKey::id)
                                              .collect(Collectors.toSet());
                 Collection<Id> incorrectIndexFields = CollectionUtil.intersect(
-                                                      il.indexFields(),
-                                                      incorrectPkIds);
+                        il.indexFields(),
+                        incorrectPkIds);
                 if (incorrectIndexFields.isEmpty()) {
                     continue;
                 }
                 // Skip if search index is not wrong
                 if (il.indexType().isSearch()) {
                     Id field = il.indexField();
-                    String cond = deletion.<String>getPropertyValue(field);
-                    String actual = element.<String>getPropertyValue(field);
+                    String cond = deletion.getPropertyValue(field);
+                    String actual = element.getPropertyValue(field);
                     if (this.tx.matchSearchIndexWords(actual, cond)) {
                         /*
                          * If query by two search index, one is correct but
@@ -1880,8 +1881,8 @@ public class GraphIndexTransaction extends AbstractTransaction {
         }
 
         private HugeElement constructErrorElem(
-                            ConditionQuery query, HugeElement element,
-                            Map<PropertyKey, Object> incorrectPKs) {
+                ConditionQuery query, HugeElement element,
+                Map<PropertyKey, Object> incorrectPKs) {
             HugeElement errorElem = element.copyAsFresh();
             Set<Id> propKeys = query.userpropKeys();
             for (Id key : propKeys) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphTransaction.java
index 23f396bcf..a09463118 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphTransaction.java
@@ -144,19 +144,19 @@ public class GraphTransaction extends IndexableTransaction {
 
         final HugeConfig conf = graph.configuration();
         this.checkCustomVertexExist =
-             conf.get(CoreOptions.VERTEX_CHECK_CUSTOMIZED_ID_EXIST);
+                conf.get(CoreOptions.VERTEX_CHECK_CUSTOMIZED_ID_EXIST);
         this.checkAdjacentVertexExist =
-             conf.get(CoreOptions.VERTEX_ADJACENT_VERTEX_EXIST);
+                conf.get(CoreOptions.VERTEX_ADJACENT_VERTEX_EXIST);
         this.lazyLoadAdjacentVertex =
-             conf.get(CoreOptions.VERTEX_ADJACENT_VERTEX_LAZY);
+                conf.get(CoreOptions.VERTEX_ADJACENT_VERTEX_LAZY);
         this.removeLeftIndexOnOverwrite =
-             conf.get(CoreOptions.VERTEX_REMOVE_LEFT_INDEX);
+                conf.get(CoreOptions.VERTEX_REMOVE_LEFT_INDEX);
         this.commitPartOfAdjacentEdges =
-             conf.get(CoreOptions.VERTEX_PART_EDGE_COMMIT_SIZE);
+                conf.get(CoreOptions.VERTEX_PART_EDGE_COMMIT_SIZE);
         this.ignoreInvalidEntry =
-             conf.get(CoreOptions.QUERY_IGNORE_INVALID_DATA);
+                conf.get(CoreOptions.QUERY_IGNORE_INVALID_DATA);
         this.optimizeAggrByIndex =
-             conf.get(CoreOptions.QUERY_OPTIMIZE_AGGR_BY_INDEX);
+                conf.get(CoreOptions.QUERY_OPTIMIZE_AGGR_BY_INDEX);
         this.batchSize = conf.get(CoreOptions.QUERY_BATCH_SIZE);
         this.pageSize = conf.get(CoreOptions.QUERY_PAGE_SIZE);
 
@@ -444,7 +444,7 @@ public class GraphTransaction extends IndexableTransaction {
                     // Eliminate the property(OUT and IN owner edge)
                     this.doEliminate(this.serializer.writeEdgeProperty(prop));
                     this.doEliminate(this.serializer.writeEdgeProperty(
-                                     prop.switchEdgeOwner()));
+                            prop.switchEdgeOwner()));
                 } else {
                     // Override edge(it will be in addedEdges & updatedEdges)
                     this.addEdge(prop.element());
@@ -473,7 +473,7 @@ public class GraphTransaction extends IndexableTransaction {
                     // Append new property(OUT and IN owner edge)
                     this.doAppend(this.serializer.writeEdgeProperty(prop));
                     this.doAppend(this.serializer.writeEdgeProperty(
-                                  prop.switchEdgeOwner()));
+                            prop.switchEdgeOwner()));
                 } else {
                     // Override edge (it will be in addedEdges & updatedEdges)
                     this.addEdge(prop.element());
@@ -535,7 +535,7 @@ public class GraphTransaction extends IndexableTransaction {
         QueryList<BackendEntry> queries = this.optimizeQueries(query, super::query);
         LOG.debug("{}", queries);
         return queries.empty() ? QueryResults.empty() :
-                                 queries.fetch(this.pageSize);
+               queries.fetch(this.pageSize);
     }
 
     @Override
@@ -810,7 +810,7 @@ public class GraphTransaction extends IndexableTransaction {
             if (vertex == null) {
                 if (checkMustExist) {
                     throw new NotFoundException(
-                              "Vertex '%s' does not exist", id);
+                            "Vertex '%s' does not exist", id);
                 } else if (adjacentVertex) {
                     assert !checkMustExist;
                     // Return undefined if adjacentVertex but !checkMustExist
@@ -1052,9 +1052,7 @@ public class GraphTransaction extends IndexableTransaction {
             if (vertex == null) {
                 return null;
             }
-            if (query.idsSize() == 1) {
-                assert vertex.getEdges().size() == 1;
-            }
+            assert query.idsSize() != 1 || vertex.getEdges().size() == 1;
             /*
              * Copy to avoid ConcurrentModificationException when removing edge
              * because HugeEdge.remove() will update edges in owner vertex
@@ -1252,8 +1250,8 @@ public class GraphTransaction extends IndexableTransaction {
         // Edge direction
         if (direction == Directions.BOTH) {
             query.query(Condition.or(
-                        Condition.eq(HugeKeys.DIRECTION, Directions.OUT),
-                        Condition.eq(HugeKeys.DIRECTION, Directions.IN)));
+                    Condition.eq(HugeKeys.DIRECTION, Directions.OUT),
+                    Condition.eq(HugeKeys.DIRECTION, Directions.IN)));
         } else {
             assert direction == Directions.OUT || direction == Directions.IN;
             query.eq(HugeKeys.DIRECTION, direction);
@@ -1414,8 +1412,8 @@ public class GraphTransaction extends IndexableTransaction {
 
         if (matched != total) {
             throw new HugeException(
-                      "Not supported querying edges by %s, expect %s",
-                      query.conditions(), EdgeId.KEYS[count]);
+                    "Not supported querying edges by %s, expect %s",
+                    query.conditions(), EdgeId.KEYS[count]);
         }
     }
 
@@ -1430,7 +1428,7 @@ public class GraphTransaction extends IndexableTransaction {
 
         boolean supportIn = this.storeFeatures().supportsQueryWithInCondition();
         for (ConditionQuery cq : ConditionQueryFlatten.flatten(
-                                 (ConditionQuery) query, supportIn)) {
+                (ConditionQuery) query, supportIn)) {
             // Optimize by sysprop
             Query q = this.optimizeQuery(cq);
             /*
@@ -1450,7 +1448,7 @@ public class GraphTransaction extends IndexableTransaction {
     private Query optimizeQuery(ConditionQuery query) {
         if (query.idsSize() > 0) {
             throw new HugeException(
-                      "Not supported querying by id and conditions: %s", query);
+                    "Not supported querying by id and conditions: %s", query);
         }
 
         Id label = query.condition(HugeKeys.LABEL);
@@ -1492,7 +1490,7 @@ public class GraphTransaction extends IndexableTransaction {
             // Serialize sort-values
             List<Id> keys = this.graph().edgeLabel(label).sortKeys();
             List<Condition> conditions =
-                            GraphIndexTransaction.constructShardConditions(
+                    GraphIndexTransaction.constructShardConditions(
                             query, keys, HugeKeys.SORT_VALUES);
             query.query(conditions);
             /*
@@ -1640,15 +1638,15 @@ public class GraphTransaction extends IndexableTransaction {
         // Check whether passed all non-null property
         @SuppressWarnings("unchecked")
         Collection<Id> nonNullKeys = CollectionUtils.subtract(
-                                     vertexLabel.properties(),
-                                     vertexLabel.nullableKeys());
+                vertexLabel.properties(),
+                vertexLabel.nullableKeys());
         if (!keys.containsAll(nonNullKeys)) {
             @SuppressWarnings("unchecked")
             Collection<Id> missed = CollectionUtils.subtract(nonNullKeys, keys);
             HugeGraph graph = this.graph();
 
             E.checkArgument(false, "All non-null property keys %s of " +
-                            "vertex label '%s' must be set, missed keys %s",
+                                   "vertex label '%s' must be set, missed keys %s",
                             graph.mapPkId2Name(nonNullKeys), vertexLabel.name(),
                             graph.mapPkId2Name(missed));
         }
@@ -1675,11 +1673,11 @@ public class GraphTransaction extends IndexableTransaction {
             HugeVertex newVertex = vertices.get(existedVertex.id());
             if (!existedVertex.label().equals(newVertex.label())) {
                 throw new HugeException(
-                          "The newly added vertex with id:'%s' label:'%s' " +
-                          "is not allowed to insert, because already exist " +
-                          "a vertex with same id and different label:'%s'",
-                          newVertex.id(), newVertex.label(),
-                          existedVertex.label());
+                        "The newly added vertex with id:'%s' label:'%s' " +
+                        "is not allowed to insert, because already exist " +
+                        "a vertex with same id and different label:'%s'",
+                        newVertex.id(), newVertex.label(),
+                        existedVertex.label());
             }
         } finally {
             CloseableIterator.closeIterator(results);
@@ -1743,8 +1741,8 @@ public class GraphTransaction extends IndexableTransaction {
     }
 
     private <T extends HugeElement> Iterator<T> filterUnmatchedRecords(
-                                                Iterator<T> results,
-                                                Query query) {
+            Iterator<T> results,
+            Query query) {
         // Filter unused or incorrect records
         return new FilterIterator<>(results, elem -> {
             // TODO: Left vertex/edge should to be auto removed via async task
@@ -1763,12 +1761,9 @@ public class GraphTransaction extends IndexableTransaction {
                 return false;
             }
             // Process results that query from left index or primary-key
-            if (query.resultType().isVertex() == elem.type().isVertex() &&
-                !rightResultFromIndexQuery(query, elem)) {
-                // Only index query will come here
-                return false;
-            }
-            return true;
+            // Only index query will come here
+            return query.resultType().isVertex() != elem.type().isVertex() ||
+                   rightResultFromIndexQuery(query, elem);
         });
     }
 
@@ -1820,7 +1815,7 @@ public class GraphTransaction extends IndexableTransaction {
     }
 
     private <T extends HugeElement> Iterator<T> filterExpiredResultFromBackend(
-                                    Query query, Iterator<T> results) {
+            Query query, Iterator<T> results) {
         if (this.store().features().supportsTtl() || query.showExpired()) {
             return results;
         }
@@ -1906,12 +1901,12 @@ public class GraphTransaction extends IndexableTransaction {
     }
 
     private <V extends HugeElement> Iterator<V> joinTxRecords(
-                                    Query query,
-                                    Iterator<V> records,
-                                    BiFunction<Query, V, V> matchFunc,
-                                    Map<Id, V> addedTxRecords,
-                                    Map<Id, V> removedTxRecords,
-                                    Map<Id, V> updatedTxRecords) {
+            Query query,
+            Iterator<V> records,
+            BiFunction<Query, V, V> matchFunc,
+            Map<Id, V> addedTxRecords,
+            Map<Id, V> removedTxRecords,
+            Map<Id, V> updatedTxRecords) {
         this.checkOwnerThread();
         // Return the origin results if there is no change in tx
         if (addedTxRecords.isEmpty() &&
@@ -1957,16 +1952,16 @@ public class GraphTransaction extends IndexableTransaction {
     private void checkTxVerticesCapacity() throws LimitExceedException {
         if (this.verticesInTxSize() >= this.verticesCapacity) {
             throw new LimitExceedException(
-                      "Vertices size has reached tx capacity %d",
-                      this.verticesCapacity);
+                    "Vertices size has reached tx capacity %d",
+                    this.verticesCapacity);
         }
     }
 
     private void checkTxEdgesCapacity() throws LimitExceedException {
         if (this.edgesInTxSize() >= this.edgesCapacity) {
             throw new LimitExceedException(
-                      "Edges size has reached tx capacity %d",
-                      this.edgesCapacity);
+                    "Edges size has reached tx capacity %d",
+                    this.edgesCapacity);
         }
     }
 
@@ -2109,7 +2104,7 @@ public class GraphTransaction extends IndexableTransaction {
         HugeType type = label.type() == HugeType.VERTEX_LABEL ?
                         HugeType.VERTEX : HugeType.EDGE;
         Query query = label.enableLabelIndex() ? new ConditionQuery(type) :
-                                                 new Query(type);
+                      new Query(type);
         query.capacity(Query.NO_CAPACITY);
         query.limit(Query.NO_LIMIT);
         if (this.store().features().supportsQueryByPage()) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/IndexableTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/IndexableTransaction.java
index e3ce7fd24..7c481b05c 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/IndexableTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/IndexableTransaction.java
@@ -17,10 +17,10 @@
 
 package org.apache.hugegraph.backend.tx;
 
-import org.apache.hugegraph.backend.store.BackendMutation;
-import org.apache.hugegraph.backend.store.BackendStore;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.BackendException;
+import org.apache.hugegraph.backend.store.BackendMutation;
+import org.apache.hugegraph.backend.store.BackendStore;
 
 public abstract class IndexableTransaction extends AbstractTransaction {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaIndexTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaIndexTransaction.java
index 54443fa0d..1fbade319 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaIndexTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaIndexTransaction.java
@@ -19,15 +19,13 @@ package org.apache.hugegraph.backend.tx;
 
 import java.util.Iterator;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.store.BackendEntry;
 import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
-import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.SchemaElement;
@@ -35,6 +33,7 @@ import org.apache.hugegraph.structure.HugeIndex;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
 public class SchemaIndexTransaction extends AbstractTransaction {
 
@@ -86,7 +85,7 @@ public class SchemaIndexTransaction extends AbstractTransaction {
         IndexLabel il = IndexLabel.label(query.resultType());
         String name = query.condition(HugeKeys.NAME);
         E.checkState(name != null, "The name in condition can't be null " +
-                     "when querying schema by name");
+                                   "when querying schema by name");
 
         ConditionQuery indexQuery;
         indexQuery = new ConditionQuery(HugeType.SECONDARY_INDEX, query);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaTransaction.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaTransaction.java
index 8af1695ba..1d7f595f0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaTransaction.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/SchemaTransaction.java
@@ -23,21 +23,18 @@ import java.util.List;
 import java.util.Set;
 import java.util.function.Consumer;
 
-import org.apache.hugegraph.backend.query.ConditionQuery;
-import org.apache.hugegraph.backend.query.Query;
-import org.apache.hugegraph.backend.query.QueryResults;
-import org.apache.hugegraph.backend.store.BackendEntry;
-import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.backend.store.SystemSchemaStore;
-import org.apache.tinkerpop.gremlin.structure.Graph;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.BackendException;
 import org.apache.hugegraph.backend.LocalCounter;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.backend.query.ConditionQuery;
+import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.backend.query.QueryResults;
+import org.apache.hugegraph.backend.store.BackendEntry;
+import org.apache.hugegraph.backend.store.BackendStore;
+import org.apache.hugegraph.backend.store.SystemSchemaStore;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.exception.NotAllowException;
 import org.apache.hugegraph.job.JobBuilder;
@@ -66,6 +63,9 @@ import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.DateUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.LockUtil;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
+
 import com.google.common.collect.ImmutableSet;
 
 public class SchemaTransaction extends IndexableTransaction implements ISchemaTransaction {
@@ -160,9 +160,9 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
         for (VertexLabel vertexLabel : vertexLabels) {
             if (vertexLabel.properties().contains(id)) {
                 throw new NotAllowException(
-                          "Not allowed to remove property key: '%s' " +
-                          "because the vertex label '%s' is still using it.",
-                          propertyKey, vertexLabel.name());
+                        "Not allowed to remove property key: '%s' " +
+                        "because the vertex label '%s' is still using it.",
+                        propertyKey, vertexLabel.name());
             }
         }
 
@@ -170,9 +170,9 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
         for (EdgeLabel edgeLabel : edgeLabels) {
             if (edgeLabel.properties().contains(id)) {
                 throw new NotAllowException(
-                          "Not allowed to remove property key: '%s' " +
-                          "because the edge label '%s' is still using it.",
-                          propertyKey, edgeLabel.name());
+                        "Not allowed to remove property key: '%s' " +
+                        "because the edge label '%s' is still using it.",
+                        propertyKey, edgeLabel.name());
             }
         }
 
@@ -469,10 +469,11 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
 
     /**
      * Currently doesn't allow to exist schema with the same name
+     *
      * @param type the query schema type
      * @param name the query schema name
      * @param <T>  SubClass of SchemaElement
-     * @return     the queried schema object
+     * @return the queried schema object
      */
     protected <T extends SchemaElement> T getSchema(HugeType type,
                                                     String name) {
@@ -559,7 +560,7 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
                 return this.serializer.writeIndexLabel((IndexLabel) schema);
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema type '%s'", schema.type()));
+                        "Unknown schema type '%s'", schema.type()));
         }
     }
 
@@ -576,7 +577,7 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
                 return (T) this.serializer.readIndexLabel(this.graph(), entry);
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema type '%s'", type));
+                        "Unknown schema type '%s'", type));
         }
     }
 
@@ -620,7 +621,7 @@ public class SchemaTransaction extends IndexableTransaction implements ISchemaTr
                 return;
             }
             throw new IllegalStateException(String.format(
-                      "Invalid system id '%s'", id));
+                    "Invalid system id '%s'", id));
         }
         E.checkState(id.number() && id.asLong() > 0L,
                      "Schema id must be number and >0, but got '%s'", id);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/config/CoreOptions.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/config/CoreOptions.java
index 388834b27..39f0f0bd7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/config/CoreOptions.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/config/CoreOptions.java
@@ -146,28 +146,28 @@ public class CoreOptions extends OptionHolder {
             );
 
     public static final ConfigOption<Boolean> RAFT_SNAPSHOT_PARALLEL_COMPRESS =
-        new ConfigOption<>(
-            "raft.snapshot_parallel_compress",
-            "Whether to enable parallel compress.",
-            disallowEmpty(),
-            false
-        );
+            new ConfigOption<>(
+                    "raft.snapshot_parallel_compress",
+                    "Whether to enable parallel compress.",
+                    disallowEmpty(),
+                    false
+            );
 
     public static final ConfigOption<Integer> RAFT_SNAPSHOT_COMPRESS_THREADS =
-        new ConfigOption<>(
-            "raft.snapshot_compress_threads",
-            "The thread number used to do snapshot compress.",
-            rangeInt(0, Integer.MAX_VALUE),
-            4
-        );
+            new ConfigOption<>(
+                    "raft.snapshot_compress_threads",
+                    "The thread number used to do snapshot compress.",
+                    rangeInt(0, Integer.MAX_VALUE),
+                    4
+            );
 
     public static final ConfigOption<Integer> RAFT_SNAPSHOT_DECOMPRESS_THREADS =
-        new ConfigOption<>(
-            "raft.snapshot_decompress_threads",
-            "The thread number used to do snapshot decompress.",
-            rangeInt(0, Integer.MAX_VALUE),
-            4
-        );
+            new ConfigOption<>(
+                    "raft.snapshot_decompress_threads",
+                    "The thread number used to do snapshot decompress.",
+                    rangeInt(0, Integer.MAX_VALUE),
+                    4
+            );
 
     public static final ConfigOption<Integer> RAFT_BACKEND_THREADS =
             new ConfigOption<>(
@@ -446,7 +446,7 @@ public class CoreOptions extends OptionHolder {
             new ConfigOption<>(
                     "edge.tx_capacity",
                     "The max size(items) of edges(uncommitted) in " +
-                     "transaction.",
+                    "transaction.",
                     rangeInt(COMMIT_BATCH, 1000000),
                     10000
             );
@@ -629,7 +629,7 @@ public class CoreOptions extends OptionHolder {
                     "Specify the mode for the text analyzer, " +
                     "the available mode of analyzer are " +
                     "ansj: [BaseAnalysis, IndexAnalysis, ToAnalysis, " +
-                           "NlpAnalysis], " +
+                    "NlpAnalysis], " +
                     "hanlp: [standard, nlp, index, nShort, shortest, speed], " +
                     "smartcn: [], " +
                     "jieba: [SEARCH, INDEX], " +
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphIoRegistry.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphIoRegistry.java
index b9154e56c..71733fa58 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphIoRegistry.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphIoRegistry.java
@@ -23,7 +23,7 @@ import org.apache.tinkerpop.gremlin.structure.io.Io;
 public class HugeGraphIoRegistry extends AbstractIoRegistry {
 
     private static final HugeGraphIoRegistry INSTANCE =
-                         new HugeGraphIoRegistry();
+            new HugeGraphIoRegistry();
 
     public static HugeGraphIoRegistry instance() {
         return INSTANCE;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphSONModule.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphSONModule.java
index c641a2668..416c3b0e4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphSONModule.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGraphSONModule.java
@@ -29,6 +29,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
@@ -40,6 +41,10 @@ import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.structure.HugeEdge;
+import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.structure.HugeProperty;
+import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.Blob;
 import org.apache.tinkerpop.gremlin.process.traversal.Path;
@@ -64,12 +69,6 @@ import org.apache.tinkerpop.shaded.jackson.databind.ser.std.DateSerializer;
 import org.apache.tinkerpop.shaded.jackson.databind.ser.std.StdSerializer;
 import org.apache.tinkerpop.shaded.jackson.databind.ser.std.UUIDSerializer;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.structure.HugeEdge;
-import org.apache.hugegraph.structure.HugeElement;
-import org.apache.hugegraph.structure.HugeProperty;
-import org.apache.hugegraph.structure.HugeVertex;
-
 @SuppressWarnings("serial")
 public class HugeGraphSONModule extends TinkerPopJacksonModule {
 
@@ -83,7 +82,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     private static final Map<Class, String> TYPE_DEFINITIONS;
 
     private static final GraphSONSchemaSerializer SCHEMA_SERIALIZER =
-                         new GraphSONSchemaSerializer();
+            new GraphSONSchemaSerializer();
 
     // NOTE: jackson will synchronize DateFormat
     private static final String DF = "yyyy-MM-dd HH:mm:ss.SSS";
@@ -158,7 +157,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         module.addSerializer(Date.class,
                              new DateSerializer(useTimestamp, DATE_FORMAT));
         module.addDeserializer(Date.class, new DateDeserializer(
-                               new DateDeserializer(), DATE_FORMAT, DF));
+                new DateDeserializer(), DATE_FORMAT, DF));
 
         module.addSerializer(UUID.class, new UUIDSerializer());
         module.addDeserializer(UUID.class, new UUIDDeserializer());
@@ -220,7 +219,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(Optional optional,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             if (optional.isPresent()) {
                 jsonGenerator.writeObject(optional.get());
             } else {
@@ -239,7 +238,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(T value,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             if (value.number()) {
                 jsonGenerator.writeNumber(value.asLong());
             } else {
@@ -252,7 +251,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
                                       JsonGenerator jsonGenerator,
                                       SerializerProvider provider,
                                       TypeSerializer typeSer)
-                                      throws IOException {
+                throws IOException {
             // https://github.com/FasterXML/jackson-databind/issues/2320
             WritableTypeId typeId = typeSer.typeId(value, JsonToken.VALUE_STRING);
             typeSer.writeTypePrefix(jsonGenerator, typeId);
@@ -262,7 +261,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     }
 
     private static class IdDeserializer<T extends Id>
-                   extends StdDeserializer<T> {
+            extends StdDeserializer<T> {
 
         public IdDeserializer(Class<T> clazz) {
             super(clazz);
@@ -272,7 +271,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         @Override
         public T deserialize(JsonParser jsonParser,
                              DeserializationContext ctxt)
-                             throws IOException {
+                throws IOException {
             Class<?> clazz = this.handledType();
             if (clazz.equals(LongId.class)) {
                 Number idValue = ctxt.readValue(jsonParser, Number.class);
@@ -292,7 +291,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     }
 
     private static class PropertyKeySerializer
-                   extends StdSerializer<PropertyKey> {
+            extends StdSerializer<PropertyKey> {
 
         public PropertyKeySerializer() {
             super(PropertyKey.class);
@@ -302,13 +301,13 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(PropertyKey pk,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             writeEntry(jsonGenerator, SCHEMA_SERIALIZER.writePropertyKey(pk));
         }
     }
 
     private static class VertexLabelSerializer
-                   extends StdSerializer<VertexLabel> {
+            extends StdSerializer<VertexLabel> {
 
         public VertexLabelSerializer() {
             super(VertexLabel.class);
@@ -318,7 +317,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(VertexLabel vl,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             writeEntry(jsonGenerator, SCHEMA_SERIALIZER.writeVertexLabel(vl));
         }
     }
@@ -333,13 +332,13 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(EdgeLabel el,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             writeEntry(jsonGenerator, SCHEMA_SERIALIZER.writeEdgeLabel(el));
         }
     }
 
     private static class IndexLabelSerializer
-                   extends StdSerializer<IndexLabel> {
+            extends StdSerializer<IndexLabel> {
 
         public IndexLabelSerializer() {
             super(IndexLabel.class);
@@ -349,14 +348,14 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serialize(IndexLabel il,
                               JsonGenerator jsonGenerator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             writeEntry(jsonGenerator, SCHEMA_SERIALIZER.writeIndexLabel(il));
         }
     }
 
     private static void writeEntry(JsonGenerator jsonGenerator,
                                    Map<HugeKeys, Object> schema)
-                                   throws IOException {
+            throws IOException {
         jsonGenerator.writeStartObject();
         for (Map.Entry<HugeKeys, Object> entry : schema.entrySet()) {
             jsonGenerator.writeFieldName(entry.getKey().string());
@@ -366,7 +365,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     }
 
     protected abstract static class HugeElementSerializer<T extends HugeElement>
-                              extends StdSerializer<T> {
+            extends StdSerializer<T> {
 
         public HugeElementSerializer(Class<T> clazz) {
             super(clazz);
@@ -374,7 +373,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
 
         public void writeIdField(String fieldName, Id id,
                                  JsonGenerator generator)
-                                 throws IOException {
+                throws IOException {
             generator.writeFieldName(fieldName);
             if (id.number()) {
                 generator.writeNumber(id.asLong());
@@ -386,7 +385,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void writePropertiesField(Collection<HugeProperty<?>> properties,
                                          JsonGenerator generator,
                                          SerializerProvider provider)
-                                         throws IOException {
+                throws IOException {
             // Start write properties
             generator.writeFieldName("properties");
             generator.writeStartObject();
@@ -405,8 +404,8 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
                     }
                 } catch (IOException e) {
                     throw new HugeException(
-                              "Failed to serialize property(%s: %s) " +
-                              "for vertex '%s'", key, val, property.element());
+                            "Failed to serialize property(%s: %s) " +
+                            "for vertex '%s'", key, val, property.element());
                 }
             }
             // End write properties
@@ -415,7 +414,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     }
 
     private static class HugeVertexSerializer
-                   extends HugeElementSerializer<HugeVertex> {
+            extends HugeElementSerializer<HugeVertex> {
 
         public HugeVertexSerializer() {
             super(HugeVertex.class);
@@ -424,7 +423,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         @Override
         public void serialize(HugeVertex vertex, JsonGenerator generator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             vertex.forceLoad();
             generator.writeStartObject();
 
@@ -442,7 +441,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serializeWithType(HugeVertex value, JsonGenerator generator,
                                       SerializerProvider provider,
                                       TypeSerializer typeSer)
-                                      throws IOException {
+                throws IOException {
             WritableTypeId typeId = typeSer.typeId(value, JsonToken.VALUE_STRING);
             typeSer.writeTypePrefix(generator, typeId);
             this.serialize(value, generator, provider);
@@ -451,7 +450,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
     }
 
     private static class HugeEdgeSerializer
-                   extends HugeElementSerializer<HugeEdge> {
+            extends HugeElementSerializer<HugeEdge> {
 
         public HugeEdgeSerializer() {
             super(HugeEdge.class);
@@ -460,7 +459,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         @Override
         public void serialize(HugeEdge edge, JsonGenerator generator,
                               SerializerProvider provider)
-                              throws IOException {
+                throws IOException {
             edge.forceLoad();
             generator.writeStartObject();
 
@@ -486,7 +485,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         public void serializeWithType(HugeEdge value, JsonGenerator generator,
                                       SerializerProvider provider,
                                       TypeSerializer typeSer)
-                                      throws IOException {
+                throws IOException {
             WritableTypeId typeId = typeSer.typeId(value, JsonToken.VALUE_STRING);
             typeSer.writeTypePrefix(generator, typeId);
             this.serialize(value, generator, provider);
@@ -591,7 +590,7 @@ public class HugeGraphSONModule extends TinkerPopJacksonModule {
         @Override
         public Blob deserialize(JsonParser jsonParser,
                                 DeserializationContext ctxt)
-                                throws IOException {
+                throws IOException {
             byte[] bytes = jsonParser.getBinaryValue();
             return Blob.wrap(bytes);
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGryoModule.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGryoModule.java
index 334eba96f..0feee228f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGryoModule.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/io/HugeGryoModule.java
@@ -40,7 +40,7 @@ import org.apache.tinkerpop.shaded.kryo.io.Output;
 public class HugeGryoModule {
 
     private static GraphSONSchemaSerializer schemaSerializer =
-                   new GraphSONSchemaSerializer();
+            new GraphSONSchemaSerializer();
 
     public static void register(HugeGraphIoRegistry io) {
         io.register(GryoIo.class, Optional.class, new OptionalSerializer());
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/ComputerJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/ComputerJob.java
index 6665304b6..5e1f93e14 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/ComputerJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/ComputerJob.java
@@ -22,8 +22,8 @@ import java.util.Map;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.job.computer.Computer;
 import org.apache.hugegraph.job.computer.ComputerPool;
-import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
 
 public class ComputerJob extends SysJob<Object> {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/EphemeralJobBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/EphemeralJobBuilder.java
index 81e9e3d24..a8a0966fa 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/EphemeralJobBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/EphemeralJobBuilder.java
@@ -17,11 +17,11 @@
 
 package org.apache.hugegraph.job;
 
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.task.HugeTask;
 import org.apache.hugegraph.task.TaskScheduler;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.util.E;
 
 public class EphemeralJobBuilder<V> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/GremlinJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/GremlinJob.java
index 491fe2942..8bde61feb 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/GremlinJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/GremlinJob.java
@@ -23,10 +23,10 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.hugegraph.backend.query.Query;
-import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.exception.LimitExceedException;
 import org.apache.hugegraph.traversal.optimize.HugeScriptTraversal;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.JsonUtil;
 
 public class GremlinJob extends UserJob<Object> {
 
@@ -71,9 +71,9 @@ public class GremlinJob extends UserJob<Object> {
         bindings.put(TASK_BIND_NAME, new GremlinJobProxy());
 
         HugeScriptTraversal<?, ?> traversal = new HugeScriptTraversal<>(
-                                                  this.graph().traversal(),
-                                                  language, gremlin,
-                                                  bindings, aliases);
+                this.graph().traversal(),
+                language, gremlin,
+                bindings, aliases);
         List<Object> results = new ArrayList<>();
         long capacity = Query.defaultCapacity(Query.NO_CAPACITY);
         try {
@@ -105,8 +105,8 @@ public class GremlinJob extends UserJob<Object> {
         }
         if (size > TASK_RESULTS_MAX_SIZE) {
             throw new LimitExceedException(
-                      "Job results size %s has exceeded the max limit %s",
-                      size, TASK_RESULTS_MAX_SIZE);
+                    "Job results size %s has exceeded the max limit %s",
+                    size, TASK_RESULTS_MAX_SIZE);
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/JobBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/JobBuilder.java
index 11868a560..fc7067b41 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/JobBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/JobBuilder.java
@@ -19,12 +19,12 @@ package org.apache.hugegraph.job;
 
 import java.util.Set;
 
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.task.HugeTask;
 import org.apache.hugegraph.task.TaskCallable;
 import org.apache.hugegraph.task.TaskScheduler;
 import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.util.E;
 
 public class JobBuilder<V> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AbstractAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AbstractAlgorithm.java
index 51cde31f6..0e249ebe2 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AbstractAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AbstractAlgorithm.java
@@ -29,18 +29,10 @@ import java.util.function.Consumer;
 
 import org.apache.commons.lang3.StringEscapeUtils;
 import org.apache.commons.lang3.mutable.MutableLong;
+import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Element;
-import org.apache.tinkerpop.gremlin.structure.Property;
-import org.apache.tinkerpop.gremlin.structure.Transaction;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
-
-import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.iterator.FilterIterator;
 import org.apache.hugegraph.iterator.FlatMapperIterator;
 import org.apache.hugegraph.job.UserJob;
@@ -55,6 +47,14 @@ import org.apache.hugegraph.util.CollectionUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.ParameterUtil;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Element;
+import org.apache.tinkerpop.gremlin.structure.Property;
+import org.apache.tinkerpop.gremlin.structure.Transaction;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
+
 import com.google.common.base.Objects;
 
 @SuppressWarnings("deprecation") // StringEscapeUtils
@@ -87,7 +87,7 @@ public abstract class AbstractAlgorithm implements Algorithm {
     public static final String KEY_TIMES = "times";
     public static final String KEY_STABLE_TIMES = "stable_times";
     public static final String KEY_PRECISION = "precision";
-    public static final String KEY_SHOW_MOD= "show_modularity";
+    public static final String KEY_SHOW_MOD = "show_modularity";
     public static final String KEY_SHOW_COMM = "show_community";
     public static final String KEY_EXPORT_COMM = "export_community";
     public static final String KEY_SKIP_ISOLATED = "skip_isolated";
@@ -104,7 +104,7 @@ public abstract class AbstractAlgorithm implements Algorithm {
     public static final long DEFAULT_DEGREE = 100L;
     public static final long DEFAULT_SAMPLE = 1L;
     public static final long DEFAULT_TIMES = 20L;
-    public static final long DEFAULT_STABLE_TIMES= 3L;
+    public static final long DEFAULT_STABLE_TIMES = 3L;
     public static final double DEFAULT_PRECISION = 1.0 / 1000;
     public static final double DEFAULT_ALPHA = 0.5D;
 
@@ -267,13 +267,13 @@ public abstract class AbstractAlgorithm implements Algorithm {
             return Directions.IN;
         } else {
             throw new IllegalArgumentException(String.format(
-                      "The value of direction must be in [OUT, IN, BOTH], " +
-                      "but got '%s'", direction));
+                    "The value of direction must be in [OUT, IN, BOTH], " +
+                    "but got '%s'", direction));
         }
     }
 
     public static class AlgoTraverser extends HugeTraverser
-                                      implements AutoCloseable {
+            implements AutoCloseable {
 
         private final UserJob<Object> job;
         protected final ExecutorService executor;
@@ -369,7 +369,7 @@ public abstract class AbstractAlgorithm implements Algorithm {
             if (value != null) {
                 vertices = filter(vertices, key, value);
             }
-           return vertices;
+            return vertices;
         }
 
         protected Iterator<Vertex> vertices(Object label, long limit) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AlgorithmPool.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AlgorithmPool.java
index 3644ab67b..0a73e2037 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AlgorithmPool.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/AlgorithmPool.java
@@ -20,9 +20,6 @@ package org.apache.hugegraph.job.algorithm;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.apache.hugegraph.job.algorithm.path.RingsDetectAlgorithm;
-import org.apache.hugegraph.job.algorithm.rank.PageRankAlgorithm;
-import org.apache.hugegraph.job.algorithm.similarity.FusiformSimilarityAlgorithm;
 import org.apache.hugegraph.job.algorithm.cent.BetweennessCentralityAlgorithm;
 import org.apache.hugegraph.job.algorithm.cent.BetweennessCentralityAlgorithmV2;
 import org.apache.hugegraph.job.algorithm.cent.ClosenessCentralityAlgorithm;
@@ -37,6 +34,9 @@ import org.apache.hugegraph.job.algorithm.comm.LouvainAlgorithm;
 import org.apache.hugegraph.job.algorithm.comm.LpaAlgorithm;
 import org.apache.hugegraph.job.algorithm.comm.TriangleCountAlgorithm;
 import org.apache.hugegraph.job.algorithm.comm.WeakConnectedComponent;
+import org.apache.hugegraph.job.algorithm.path.RingsDetectAlgorithm;
+import org.apache.hugegraph.job.algorithm.rank.PageRankAlgorithm;
+import org.apache.hugegraph.job.algorithm.similarity.FusiformSimilarityAlgorithm;
 import org.apache.hugegraph.util.E;
 
 public class AlgorithmPool {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/BfsTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/BfsTraverser.java
index b3d12f9f9..4a6cda246 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/BfsTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/BfsTraverser.java
@@ -24,15 +24,14 @@ import java.util.Map;
 import java.util.Stack;
 
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.tinkerpop.gremlin.structure.Edge;
 
 public abstract class BfsTraverser<T extends BfsTraverser.Node>
-                extends AbstractAlgorithm.AlgoTraverser
-                implements AutoCloseable {
+        extends AbstractAlgorithm.AlgoTraverser
+        implements AutoCloseable {
 
     private final Stack<Id> traversedVertices = new Stack<>();
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/Consumers.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/Consumers.java
index bc4ece38b..dc04bdf60 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/Consumers.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/Consumers.java
@@ -25,12 +25,11 @@ import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.task.TaskManager.ContextCallable;
 import org.apache.hugegraph.util.ExecutorUtil;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public class Consumers<V> {
 
@@ -147,7 +146,7 @@ public class Consumers<V> {
             try {
                 this.queue.put(v);
             } catch (InterruptedException e) {
-                LOG.warn("Interrupted", e);;
+                LOG.warn("Interrupted", e);
             }
         }
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountEdgeAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountEdgeAlgorithm.java
index 62252b7d4..fd20f8a82 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountEdgeAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountEdgeAlgorithm.java
@@ -22,10 +22,9 @@ import java.util.Iterator;
 import java.util.Map;
 
 import org.apache.commons.lang3.mutable.MutableLong;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.util.JsonUtil;
+import org.apache.tinkerpop.gremlin.structure.Edge;
 
 public class CountEdgeAlgorithm extends AbstractAlgorithm {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountVertexAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountVertexAlgorithm.java
index 960f8fc8f..c325370b3 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountVertexAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/CountVertexAlgorithm.java
@@ -22,11 +22,10 @@ import java.util.Iterator;
 import java.util.Map;
 
 import org.apache.commons.lang3.mutable.MutableLong;
+import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-
 public class CountVertexAlgorithm extends AbstractAlgorithm {
 
     @Override
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/SubgraphStatAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/SubgraphStatAlgorithm.java
index 2bf2d3687..d6a1be8aa 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/SubgraphStatAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/SubgraphStatAlgorithm.java
@@ -21,15 +21,10 @@ import java.util.Iterator;
 import java.util.Map;
 
 import org.apache.commons.configuration2.PropertiesConfiguration;
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.config.CoreOptions;
-import org.apache.hugegraph.util.ParameterUtil;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.StandardHugeGraph;
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.task.HugeTask;
@@ -38,6 +33,11 @@ import org.apache.hugegraph.traversal.optimize.HugeScriptTraversal;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.Log;
+import org.apache.hugegraph.util.ParameterUtil;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableMap;
 
 public class SubgraphStatAlgorithm extends AbstractAlgorithm {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/AbstractCentAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/AbstractCentAlgorithm.java
index 4a76b77cb..8ab6ca81f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/AbstractCentAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/AbstractCentAlgorithm.java
@@ -25,6 +25,13 @@ import java.util.Map;
 
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.iterator.MapperIterator;
+import org.apache.hugegraph.job.UserJob;
+import org.apache.hugegraph.job.algorithm.AbstractAlgorithm;
+import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.structure.HugeVertex;
+import org.apache.hugegraph.type.define.Directions;
+import org.apache.hugegraph.util.Log;
 import org.apache.tinkerpop.gremlin.process.traversal.Order;
 import org.apache.tinkerpop.gremlin.process.traversal.Pop;
 import org.apache.tinkerpop.gremlin.process.traversal.Scope;
@@ -35,14 +42,6 @@ import org.apache.tinkerpop.gremlin.structure.Direction;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.iterator.MapperIterator;
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.job.algorithm.AbstractAlgorithm;
-import org.apache.hugegraph.structure.HugeElement;
-import org.apache.hugegraph.structure.HugeVertex;
-import org.apache.hugegraph.type.define.Directions;
-import org.apache.hugegraph.util.Log;
-
 public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
 
     private static final Logger LOG = Log.logger(AbstractCentAlgorithm.class);
@@ -72,11 +71,11 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
         }
 
         protected GraphTraversal<Vertex, Vertex> constructSource(
-                                                 String sourceLabel,
-                                                 long sourceSample,
-                                                 String sourceCLabel) {
+                String sourceLabel,
+                long sourceSample,
+                String sourceCLabel) {
             GraphTraversal<Vertex, Vertex> t = this.graph().traversal()
-                                                           .withSack(1f).V();
+                                                   .withSack(1f).V();
 
             if (sourceLabel != null) {
                 t = t.hasLabel(sourceLabel);
@@ -95,9 +94,9 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
         }
 
         protected GraphTraversal<Vertex, Vertex> constructPath(
-                  GraphTraversal<Vertex, Vertex> t, Directions dir,
-                  String label, long degree, long sample,
-                  String sourceLabel, String sourceCLabel) {
+                GraphTraversal<Vertex, Vertex> t, Directions dir,
+                String label, long degree, long sample,
+                String sourceLabel, String sourceCLabel) {
             GraphTraversal<?, Vertex> unit = constructPathUnit(dir, label,
                                                                degree, sample,
                                                                sourceLabel,
@@ -108,10 +107,10 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
         }
 
         protected GraphTraversal<Vertex, Vertex> constructPathUnit(
-                                                 Directions dir, String label,
-                                                 long degree, long sample,
-                                                 String sourceLabel,
-                                                 String sourceCLabel) {
+                Directions dir, String label,
+                long degree, long sample,
+                String sourceLabel,
+                String sourceCLabel) {
             if (dir == null) {
                 dir = Directions.BOTH;
             }
@@ -139,10 +138,10 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
         }
 
         protected <V> GraphTraversal<V, V> filterNonShortestPath(
-                                           GraphTraversal<V, V> t,
-                                           boolean keepOneShortestPath) {
+                GraphTraversal<V, V> t,
+                boolean keepOneShortestPath) {
             long size = this.graph().traversal().V().limit(100000L)
-                                                    .count().next();
+                            .count().next();
             Map<Pair<Id, Id>, Integer> triples = new HashMap<>((int) size);
             return t.filter(it -> {
                 Id start = it.<HugeElement>path(Pop.first, "v").id();
@@ -168,15 +167,15 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
         }
 
         protected GraphTraversal<Vertex, Id> substractPath(
-                                             GraphTraversal<Vertex, Vertex> t,
-                                             boolean withBoundary) {
+                GraphTraversal<Vertex, Vertex> t,
+                boolean withBoundary) {
             // t.select(Pop.all, "v").unfold().id()
             return t.select(Pop.all, "v").flatMap(it -> {
                 List<?> path = (List<?>) it.get();
                 if (withBoundary) {
                     @SuppressWarnings("unchecked")
                     Iterator<HugeVertex> items = (Iterator<HugeVertex>)
-                                                 path.iterator();
+                            path.iterator();
                     return new MapperIterator<>(items, HugeVertex::id);
                 }
                 int len = path.size();
@@ -185,11 +184,11 @@ public abstract class AbstractCentAlgorithm extends AbstractAlgorithm {
                 }
 
                 LOG.debug("CentAlgorithm substract path: {}", path);
-                path.remove(path.size() -1);
+                path.remove(path.size() - 1);
                 path.remove(0);
                 @SuppressWarnings("unchecked")
                 Iterator<HugeVertex> items = (Iterator<HugeVertex>)
-                                             path.iterator();
+                        path.iterator();
                 return new MapperIterator<>(items, HugeVertex::id);
             });
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithm.java
index b63bab404..512d14a15 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithm.java
@@ -25,16 +25,15 @@ import java.util.Map;
 import org.apache.commons.lang3.mutable.MutableFloat;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.SplicingIdGenerator;
+import org.apache.hugegraph.job.UserJob;
+import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.type.define.Directions;
 import org.apache.tinkerpop.gremlin.process.traversal.P;
 import org.apache.tinkerpop.gremlin.process.traversal.Pop;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.structure.HugeElement;
-import org.apache.hugegraph.type.define.Directions;
-
 public class BetweennessCentralityAlgorithm extends AbstractCentAlgorithm {
 
     @Override
@@ -97,7 +96,7 @@ public class BetweennessCentralityAlgorithm extends AbstractCentAlgorithm {
         }
 
         protected GraphTraversal<Vertex, ?> groupPathByEndpoints(
-                                            GraphTraversal<Vertex, Vertex> t) {
+                GraphTraversal<Vertex, Vertex> t) {
             return t.map(it -> {
                 // t.select(Pop.all, "v").unfold().id()
                 List<HugeElement> path = it.path(Pop.all, "v");
@@ -112,13 +111,13 @@ public class BetweennessCentralityAlgorithm extends AbstractCentAlgorithm {
                 List<Id> path = (List<Id>) it;
                 assert path.size() >= 2;
                 String first = path.get(0).toString();
-                String last = path.get(path.size() -1).toString();
+                String last = path.get(path.size() - 1).toString();
                 return SplicingIdGenerator.concat(first, last);
             }).unfold();
         }
 
         protected GraphTraversal<Vertex, ?> computeBetweenness(
-                                            GraphTraversal<Vertex, ?> t) {
+                GraphTraversal<Vertex, ?> t) {
             return t.fold(new HashMap<Id, MutableFloat>(), (results, it) -> {
                 @SuppressWarnings("unchecked")
                 Map.Entry<Id, List<?>> entry = (Map.Entry<Id, List<?>>) it;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithmV2.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithmV2.java
index 63dd9210b..d33dc54eb 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithmV2.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/BetweennessCentralityAlgorithmV2.java
@@ -24,13 +24,12 @@ import java.util.Map;
 import org.apache.commons.lang3.mutable.MutableFloat;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Query;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.job.algorithm.BfsTraverser;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 
 public class BetweennessCentralityAlgorithmV2 extends AbstractCentAlgorithm {
 
@@ -129,7 +128,7 @@ public class BetweennessCentralityAlgorithmV2 extends AbstractCentAlgorithm {
                 return;
             }
             MutableFloat betweenness = this.globalBetweennesses.get(
-                                       currentVertex);
+                    currentVertex);
             if (betweenness == null) {
                 betweenness = new MutableFloat(0.0F);
                 this.globalBetweennesses.put(currentVertex, betweenness);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithm.java
index cec440615..db7eff5a4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithm.java
@@ -19,6 +19,8 @@ package org.apache.hugegraph.job.algorithm.cent;
 
 import java.util.Map;
 
+import org.apache.hugegraph.job.UserJob;
+import org.apache.hugegraph.type.define.Directions;
 import org.apache.tinkerpop.gremlin.process.traversal.Operator;
 import org.apache.tinkerpop.gremlin.process.traversal.P;
 import org.apache.tinkerpop.gremlin.process.traversal.Pop;
@@ -27,9 +29,6 @@ import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.type.define.Directions;
-
 public class ClosenessCentralityAlgorithm extends AbstractCentAlgorithm {
 
     public static final long DEFAULT_DEGREE = 100L;
@@ -96,8 +95,8 @@ public class ClosenessCentralityAlgorithm extends AbstractCentAlgorithm {
              */
             GraphTraversal<Vertex, ?> tg;
             tg = t.group().by(__.select(Pop.first, "v").id())
-                          .by(__.select(Pop.all, "v").count(Scope.local)
-                                .math("_-1").sack(Operator.div).sack().sum());
+                  .by(__.select(Pop.all, "v").count(Scope.local)
+                        .math("_-1").sack(Operator.div).sack().sum());
             GraphTraversal<Vertex, ?> tLimit = topN(tg, topN);
 
             return this.execute(tLimit, tLimit::next);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithmV2.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithmV2.java
index 3879f29dd..e95eae587 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithmV2.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/ClosenessCentralityAlgorithmV2.java
@@ -16,6 +16,10 @@
  */
 package org.apache.hugegraph.job.algorithm.cent;
 
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.exception.NotSupportException;
@@ -26,10 +30,6 @@ import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.Map;
-
 public class ClosenessCentralityAlgorithmV2 extends AbstractCentAlgorithm {
 
     @Override
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/DegreeCentralityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/DegreeCentralityAlgorithm.java
index 4c44d2632..5a995d6dd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/DegreeCentralityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/DegreeCentralityAlgorithm.java
@@ -23,13 +23,12 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 
 public class DegreeCentralityAlgorithm extends AbstractCentAlgorithm {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/EigenvectorCentralityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/EigenvectorCentralityAlgorithm.java
index 13e4a6dc9..ef45587d4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/EigenvectorCentralityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/EigenvectorCentralityAlgorithm.java
@@ -19,14 +19,13 @@ package org.apache.hugegraph.job.algorithm.cent;
 
 import java.util.Map;
 
+import org.apache.hugegraph.job.UserJob;
+import org.apache.hugegraph.type.define.Directions;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.type.define.Directions;
-
 public class EigenvectorCentralityAlgorithm extends AbstractCentAlgorithm {
 
     public static final long DEFAULT_DEGREE = 100L;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithm.java
index 30890987b..8371f7380 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithm.java
@@ -19,15 +19,14 @@ package org.apache.hugegraph.job.algorithm.cent;
 
 import java.util.Map;
 
+import org.apache.hugegraph.job.UserJob;
+import org.apache.hugegraph.type.define.Directions;
+import org.apache.hugegraph.util.ParameterUtil;
 import org.apache.tinkerpop.gremlin.process.traversal.P;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.type.define.Directions;
-import org.apache.hugegraph.util.ParameterUtil;
-
 public class StressCentralityAlgorithm extends AbstractCentAlgorithm {
 
     public static final String KEY_WITH_BOUNDARY = "with_boundary";
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithmV2.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithmV2.java
index 314c2b837..5817e0386 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithmV2.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/cent/StressCentralityAlgorithmV2.java
@@ -24,13 +24,12 @@ import java.util.Map;
 import org.apache.commons.lang3.mutable.MutableLong;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.Query;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.job.algorithm.BfsTraverser;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 
 public class StressCentralityAlgorithmV2 extends AbstractCentAlgorithm {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/ClusterCoefficientAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/ClusterCoefficientAlgorithm.java
index 6399b86e6..e0f0ca5a6 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/ClusterCoefficientAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/ClusterCoefficientAlgorithm.java
@@ -73,7 +73,7 @@ public class ClusterCoefficientAlgorithm extends AbstractCommAlgorithm {
             assert triangles <= triads;
             double coefficient = triads == 0L ? 0d : 1d * triangles / triads;
 
-            @SuppressWarnings({ "unchecked", "rawtypes" })
+            @SuppressWarnings({"unchecked", "rawtypes"})
             Map<String, Double> converted = (Map) results;
             converted.put("cluster_coefficient", coefficient);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/KCoreAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/KCoreAlgorithm.java
index 58a63986c..e51aa27ac 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/KCoreAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/KCoreAlgorithm.java
@@ -26,11 +26,8 @@ import java.util.Set;
 
 import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.lang3.mutable.MutableInt;
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.traversal.algorithm.FusiformSimilarityTraverser;
 import org.apache.hugegraph.type.define.Directions;
@@ -38,6 +35,9 @@ import org.apache.hugegraph.util.CollectionUtil;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.ParameterUtil;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
+
 import com.google.common.collect.ImmutableSet;
 
 public class KCoreAlgorithm extends AbstractCommAlgorithm {
@@ -198,7 +198,7 @@ public class KCoreAlgorithm extends AbstractCommAlgorithm {
                                                            .iterator().next();
             Id source = entry.getKey();
             Set<KcoreSimilar> similars = new HashSet<>();
-            for (Similar similar: entry.getValue()) {
+            for (Similar similar : entry.getValue()) {
                 similars.add(new KcoreSimilar(similar));
             }
 
@@ -236,7 +236,8 @@ public class KCoreAlgorithm extends AbstractCommAlgorithm {
                     }
 
                     Set<Id> survivedIds = new HashSet<>(CollectionUtils
-                                          .subtract(similar.ids(), failedIds));
+                                                                .subtract(similar.ids(),
+                                                                          failedIds));
                     if (survivedIds.size() < k) {
                         for (Id id : survivedIds) {
                             counts.get(id).decrement();
@@ -247,7 +248,7 @@ public class KCoreAlgorithm extends AbstractCommAlgorithm {
                     }
                 }
                 similars = new HashSet<>(CollectionUtils.subtract(
-                                         similars, failedSimilars));
+                        similars, failedSimilars));
             } while (!stop);
 
             if (similars.isEmpty()) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainAlgorithm.java
index 5b5a8ca5f..17bfd22ad 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainAlgorithm.java
@@ -62,8 +62,8 @@ public class LouvainAlgorithm extends AbstractCommAlgorithm {
         Long exportPass = exportCommunity(parameters);
 
         try (LouvainTraverser traverser = new LouvainTraverser(
-                                          job, workers, degree,
-                                          label, clabel, skipIsolated)) {
+                job, workers, degree,
+                label, clabel, skipIsolated)) {
             if (clearPass != null) {
                 return traverser.clearPass(clearPass.intValue());
             } else if (modPass != null) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainTraverser.java
index 8b8158b16..6b125d689 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LouvainTraverser.java
@@ -40,28 +40,28 @@ import org.apache.commons.lang3.mutable.MutableInt;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.job.algorithm.Consumers;
-import org.apache.hugegraph.schema.SchemaLabel;
-import org.apache.hugegraph.schema.SchemaManager;
-import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
-import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.T;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.iterator.ListIterator;
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.job.algorithm.AbstractAlgorithm;
 import org.apache.hugegraph.job.algorithm.AbstractAlgorithm.AlgoTraverser;
+import org.apache.hugegraph.job.algorithm.Consumers;
+import org.apache.hugegraph.schema.SchemaLabel;
+import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.Log;
 import org.apache.hugegraph.util.StringEncoding;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.T;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableMap;
 
 public class LouvainTraverser extends AlgoTraverser {
@@ -107,7 +107,7 @@ public class LouvainTraverser extends AlgoTraverser {
         if (this.graph().existsVertexLabel(label) ||
             this.graph().existsEdgeLabel(label)) {
             throw new IllegalArgumentException(
-                      "Please clear historical results before proceeding");
+                    "Please clear historical results before proceeding");
         }
 
         SchemaManager schema = this.graph().schema();
@@ -136,7 +136,7 @@ public class LouvainTraverser extends AlgoTraverser {
                   .create();
         } catch (ExistedException e) {
             throw new IllegalArgumentException(
-                      "Please clear historical results before proceeding", e);
+                    "Please clear historical results before proceeding", e);
         }
     }
 
@@ -452,11 +452,11 @@ public class LouvainTraverser extends AlgoTraverser {
         LOG.info("Merge community for pass {}", pass);
         // merge each community as a vertex
         Collection<Pair<Community, Set<Id>>> comms = this.cache.communities();
-        assert this.skipIsolated || this.allMembersExist(comms,  pass - 1);
+        assert this.skipIsolated || this.allMembersExist(comms, pass - 1);
         this.cache.resetVertexWeight();
 
         Consumers<Pair<Community, Set<Id>>> consumers = new Consumers<>(
-                                                        this.executor, pair -> {
+                this.executor, pair -> {
             // called by multi-threads
             this.mergeCommunity(pass, pair.getLeft(), pair.getRight());
         }, () -> {
@@ -551,10 +551,10 @@ public class LouvainTraverser extends AlgoTraverser {
                        tryNext(this.g.V().hasLabel(label).count()).longValue();
         } else {
             expected = tryNext(this.g.V().hasLabel(labelOfPassN(lastPass))
-                                         .values(C_WEIGHT).sum());
+                                     .values(C_WEIGHT).sum());
         }
         Number actual = tryNext(this.g.V().hasLabel(label)
-                                          .values(C_WEIGHT).sum());
+                                      .values(C_WEIGHT).sum());
         boolean allExist = actual.floatValue() == expected.floatValue();
         assert allExist : actual + "!=" + expected;
         return allExist;
@@ -821,7 +821,7 @@ public class LouvainTraverser extends AlgoTraverser {
         @Override
         public String toString() {
             return String.format("[%s](size=%s weight=%s kin=%s kout=%s)",
-                                 this.cid , this.size, this.weight,
+                                 this.cid, this.size, this.weight,
                                  this.kin, this.kout);
         }
     }
@@ -900,7 +900,7 @@ public class LouvainTraverser extends AlgoTraverser {
             return IdGenerator.of(id);
         }
 
-        public Collection<Pair<Community, Set<Id>>> communities(){
+        public Collection<Pair<Community, Set<Id>>> communities() {
             // TODO: get communities from backend store instead of ram
             Map<Id, Pair<Community, Set<Id>>> comms = new HashMap<>();
             for (Entry<Id, Community> e : this.vertex2Community.entrySet()) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LpaAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LpaAlgorithm.java
index 70d677a0f..6e9292128 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LpaAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/LpaAlgorithm.java
@@ -27,15 +27,15 @@ import java.util.concurrent.atomic.AtomicLong;
 
 import org.apache.commons.lang3.mutable.MutableInt;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
+import org.apache.hugegraph.type.define.Directions;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.process.traversal.Scope;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
-import org.apache.hugegraph.job.UserJob;
-import org.apache.hugegraph.type.define.Directions;
-import org.apache.hugegraph.util.E;
 import com.google.common.collect.ImmutableMap;
 
 public class LpaAlgorithm extends AbstractCommAlgorithm {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/WeakConnectedComponent.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/WeakConnectedComponent.java
index d26fde6e1..674ec5023 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/WeakConnectedComponent.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/comm/WeakConnectedComponent.java
@@ -24,17 +24,17 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.schema.SchemaManager;
+import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableMap;
 
 public class WeakConnectedComponent extends AbstractCommAlgorithm {
@@ -101,16 +101,16 @@ public class WeakConnectedComponent extends AbstractCommAlgorithm {
                         }
                     } else {
                         changeCount += this.findAndSetMinComponent(
-                                       currentSourceVertexId,
-                                       adjacentVertices);
+                                currentSourceVertexId,
+                                adjacentVertices);
                         adjacentVertices = new ArrayList<>();
                         currentSourceVertexId = sourceVertexId;
                         adjacentVertices.add(targetVertexId);
                     }
                 }
                 changeCount += this.findAndSetMinComponent(
-                               currentSourceVertexId,
-                               adjacentVertices);
+                        currentSourceVertexId,
+                        adjacentVertices);
                 LOG.debug("iterationTimes:{}, changeCount:{}",
                           times, changeCount);
 
@@ -145,7 +145,8 @@ public class WeakConnectedComponent extends AbstractCommAlgorithm {
 
         /**
          * process for a vertex and its adjacentVertices
-         * @param sourceVertexId the source vertex
+         *
+         * @param sourceVertexId   the source vertex
          * @param adjacentVertices the adjacent vertices attached to source
          *                         vertex
          * @return the count of vertex that changed Component
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/rank/PageRankAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/rank/PageRankAlgorithm.java
index f5d43bb13..5c11c37e1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/rank/PageRankAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/rank/PageRankAlgorithm.java
@@ -17,27 +17,26 @@
 
 package org.apache.hugegraph.job.algorithm.rank;
 
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-import org.slf4j.Logger;
-
+import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.job.algorithm.comm.AbstractCommAlgorithm;
 import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.structure.HugeVertex;
+import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableMap;
 
 public class PageRankAlgorithm extends AbstractCommAlgorithm {
@@ -96,11 +95,11 @@ public class PageRankAlgorithm extends AbstractCommAlgorithm {
          * If topN > 0, then return topN elements with rank value in json.
          */
         private Object pageRank(double alpha,
-                               int maxTimes,
-                               double precision,
-                               long degree,
-                               Directions direction,
-                               long topN) {
+                                int maxTimes,
+                                double precision,
+                                long degree,
+                                Directions direction,
+                                long topN) {
             this.initSchema();
 
             int times;
@@ -155,10 +154,10 @@ public class PageRankAlgorithm extends AbstractCommAlgorithm {
             if (topN > 0) {
                 Object topNJson = this.getTopRank(topN);
                 return ImmutableMap.of("alpha", alpha,
-                        "iteration_times", times,
-                        "last_changed_rank", changedRank,
-                        "times", maxTimes,
-                        "top", topNJson);
+                                       "iteration_times", times,
+                                       "last_changed_rank", changedRank,
+                                       "times", maxTimes,
+                                       "top", topNJson);
             }
             return ImmutableMap.of("alpha", alpha,
                                    "iteration_times", times,
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/similarity/FusiformSimilarityAlgorithm.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/similarity/FusiformSimilarityAlgorithm.java
index 8462e1c95..0d153091e 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/similarity/FusiformSimilarityAlgorithm.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/algorithm/similarity/FusiformSimilarityAlgorithm.java
@@ -20,8 +20,6 @@ package org.apache.hugegraph.job.algorithm.similarity;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.job.UserJob;
 import org.apache.hugegraph.job.algorithm.AbstractAlgorithm;
@@ -32,6 +30,7 @@ import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.JsonUtil;
 import org.apache.hugegraph.util.ParameterUtil;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
 
 public class FusiformSimilarityAlgorithm extends AbstractAlgorithm {
 
@@ -164,7 +163,7 @@ public class FusiformSimilarityAlgorithm extends AbstractAlgorithm {
             HugeGraph graph = this.graph();
 
             FusiformSimilarityTraverser traverser =
-                                        new FusiformSimilarityTraverser(graph);
+                    new FusiformSimilarityTraverser(graph);
 
             AtomicLong count = new AtomicLong(0L);
             JsonMap similarsJson = new JsonMap();
@@ -172,11 +171,11 @@ public class FusiformSimilarityAlgorithm extends AbstractAlgorithm {
 
             this.traverse(sourceLabel, sourceCLabel, v -> {
                 SimilarsMap similars = traverser.fusiformSimilarity(
-                                       IteratorUtils.of(v), direction,
-                                       label, minNeighbors, alpha,
-                                       minSimilars, (int) topSimilars,
-                                       groupProperty, minGroups, degree,
-                                       MAX_CAPACITY, NO_LIMIT, true);
+                        IteratorUtils.of(v), direction,
+                        label, minNeighbors, alpha,
+                        minSimilars, (int) topSimilars,
+                        groupProperty, minGroups, degree,
+                        MAX_CAPACITY, NO_LIMIT, true);
                 if (similars.isEmpty()) {
                     return;
                 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/AbstractComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/AbstractComputer.java
index 73400b462..5158ec791 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/AbstractComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/AbstractComputer.java
@@ -90,7 +90,7 @@ public abstract class AbstractComputer implements Computer {
             this.initializeConfig((ComputerJob) job);
         } catch (Exception e) {
             throw new HugeException(
-                      "Failed to initialize computer config file", e);
+                    "Failed to initialize computer config file", e);
         }
 
         // Set current computer job's specified parameters
@@ -112,8 +112,8 @@ public abstract class AbstractComputer implements Computer {
 
             StringBuilder output = new StringBuilder();
             try (LineNumberReader reader = new LineNumberReader(
-                                           new InputStreamReader(
-                                           process.getInputStream()))) {
+                    new InputStreamReader(
+                            process.getInputStream()))) {
                 String line;
                 while ((line = reader.readLine()) != null) {
                     output.append(line).append("\n");
@@ -165,7 +165,7 @@ public abstract class AbstractComputer implements Computer {
 
     private Map<String, Object> readSubConfig(String sub) {
         List<HierarchicalConfiguration<ImmutableNode>> nodes =
-                                       this.config.childConfigurationsAt(sub);
+                this.config.childConfigurationsAt(sub);
 
         E.checkArgument(nodes.size() >= 1,
                         "'%s' must be contained in config '%s'", sub);
@@ -176,9 +176,9 @@ public abstract class AbstractComputer implements Computer {
         for (HierarchicalConfiguration<ImmutableNode> node : nodes) {
             NodeModel<ImmutableNode> nodeModel = node.getNodeModel();
             E.checkArgument(nodeModel != null &&
-                           (nodeHandler = nodeModel.getNodeHandler()) != null &&
-                           (root = nodeHandler.getRootNode()) != null,
-                           "Node '%s' must contain root", node);
+                            (nodeHandler = nodeModel.getNodeHandler()) != null &&
+                            (root = nodeHandler.getRootNode()) != null,
+                            "Node '%s' must contain root", node);
             results.put(root.getNodeName(), root.getValue());
         }
 
@@ -198,7 +198,7 @@ public abstract class AbstractComputer implements Computer {
     }
 
     protected abstract Map<String, Object> checkAndCollectParameters(
-                                           Map<String, Object> parameters);
+            Map<String, Object> parameters);
 
     protected static int maxSteps(Map<String, Object> parameters) {
         if (!parameters.containsKey(MAX_STEPS)) {
@@ -259,8 +259,8 @@ public abstract class AbstractComputer implements Computer {
             return Directions.IN;
         } else {
             throw new IllegalArgumentException(String.format(
-                      "The value of direction must be in [OUT, IN, BOTH], " +
-                      "but got '%s'", direction));
+                    "The value of direction must be in [OUT, IN, BOTH], " +
+                    "but got '%s'", direction));
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LouvainComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LouvainComputer.java
index cbc2aa4a8..f90720502 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LouvainComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LouvainComputer.java
@@ -19,9 +19,10 @@ package org.apache.hugegraph.job.computer;
 
 import java.util.Map;
 
-import org.apache.hugegraph.util.ParameterUtil;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.ParameterUtil;
+
 import com.google.common.collect.ImmutableMap;
 
 public class LouvainComputer extends AbstractComputer {
@@ -64,7 +65,7 @@ public class LouvainComputer extends AbstractComputer {
 
     @Override
     protected Map<String, Object> checkAndCollectParameters(
-                                  Map<String, Object> parameters) {
+            Map<String, Object> parameters) {
         return ImmutableMap.of(TIMES, times(parameters),
                                PRECISION, precision(parameters),
                                DIRECTION, direction(parameters),
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LpaComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LpaComputer.java
index 61c6bb8db..89618ee7c 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LpaComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/LpaComputer.java
@@ -21,6 +21,7 @@ import java.util.Map;
 
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.ParameterUtil;
+
 import com.google.common.collect.ImmutableMap;
 
 public class LpaComputer extends AbstractComputer {
@@ -51,7 +52,7 @@ public class LpaComputer extends AbstractComputer {
 
     @Override
     protected Map<String, Object> checkAndCollectParameters(
-                                  Map<String, Object> parameters) {
+            Map<String, Object> parameters) {
         return ImmutableMap.of(TIMES, times(parameters),
                                PROPERTY, property(parameters),
                                PRECISION, precision(parameters),
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/PageRankComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/PageRankComputer.java
index 89fe1b67e..51388c08c 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/PageRankComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/PageRankComputer.java
@@ -21,6 +21,7 @@ import java.util.Map;
 
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.ParameterUtil;
+
 import com.google.common.collect.ImmutableMap;
 
 public class PageRankComputer extends AbstractComputer {
@@ -49,7 +50,7 @@ public class PageRankComputer extends AbstractComputer {
 
     @Override
     protected Map<String, Object> checkAndCollectParameters(
-                                  Map<String, Object> parameters) {
+            Map<String, Object> parameters) {
         return ImmutableMap.of(MAX_STEPS, maxSteps(parameters),
                                ALPHA, alpha(parameters),
                                PRECISION, precision(parameters));
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/TriangleCountComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/TriangleCountComputer.java
index e794f4ba7..73206f24a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/TriangleCountComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/TriangleCountComputer.java
@@ -43,7 +43,7 @@ public class TriangleCountComputer extends AbstractComputer {
 
     @Override
     protected Map<String, Object> checkAndCollectParameters(
-                                  Map<String, Object> parameters) {
+            Map<String, Object> parameters) {
         return ImmutableMap.of(DIRECTION, direction(parameters),
                                DEGREE, degree(parameters));
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/WeakConnectedComponentComputer.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/WeakConnectedComponentComputer.java
index 60c740f2e..d84522b28 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/WeakConnectedComponentComputer.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/computer/WeakConnectedComponentComputer.java
@@ -43,7 +43,7 @@ public class WeakConnectedComponentComputer extends AbstractComputer {
 
     @Override
     protected Map<String, Object> checkAndCollectParameters(
-                                  Map<String, Object> parameters) {
+            Map<String, Object> parameters) {
         return ImmutableMap.of(MAX_STEPS, maxSteps(parameters),
                                PRECISION, precision(parameters));
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/EdgeLabelRemoveJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/EdgeLabelRemoveJob.java
index 5d24fc332..e8d3461e3 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/EdgeLabelRemoveJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/EdgeLabelRemoveJob.java
@@ -19,6 +19,7 @@ package org.apache.hugegraph.job.schema;
 
 import java.util.Set;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
@@ -26,7 +27,7 @@ import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.LockUtil;
-import org.apache.hugegraph.HugeGraphParams;
+
 import com.google.common.collect.ImmutableSet;
 
 public class EdgeLabelRemoveJob extends SchemaJob {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRebuildJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRebuildJob.java
index 480a00d7e..5e4acf92e 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRebuildJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRebuildJob.java
@@ -26,18 +26,18 @@ import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.type.define.SchemaStatus;
-import org.apache.hugegraph.util.LockUtil;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
-
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.schema.SchemaLabel;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeElement;
+import org.apache.hugegraph.type.HugeType;
+import org.apache.hugegraph.type.define.SchemaStatus;
+import org.apache.hugegraph.util.LockUtil;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+
 import com.google.common.collect.ImmutableSet;
 
 public class IndexLabelRebuildJob extends SchemaJob {
@@ -79,7 +79,7 @@ public class IndexLabelRebuildJob extends SchemaJob {
             default:
                 assert schema.type() == HugeType.PROPERTY_KEY;
                 throw new AssertionError(String.format(
-                          "The %s can't rebuild index", schema.type()));
+                        "The %s can't rebuild index", schema.type()));
         }
     }
 
@@ -186,7 +186,7 @@ public class IndexLabelRebuildJob extends SchemaJob {
                 return this.graph().indexLabel(id);
             default:
                 throw new AssertionError(String.format(
-                          "Invalid HugeType '%s' for rebuild", type));
+                        "Invalid HugeType '%s' for rebuild", type));
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRemoveJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRemoveJob.java
index 213ed949e..b87978d8b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRemoveJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/IndexLabelRemoveJob.java
@@ -17,6 +17,7 @@
 
 package org.apache.hugegraph.job.schema;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
@@ -24,7 +25,6 @@ import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.LockUtil;
-import org.apache.hugegraph.HugeGraphParams;
 
 public class IndexLabelRemoveJob extends SchemaJob {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/OlapPropertyKeyClearJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/OlapPropertyKeyClearJob.java
index c94e5470f..155a6b8bf 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/OlapPropertyKeyClearJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/OlapPropertyKeyClearJob.java
@@ -17,6 +17,7 @@
 
 package org.apache.hugegraph.job.schema;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
@@ -24,7 +25,6 @@ import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.LockUtil;
-import org.apache.hugegraph.HugeGraphParams;
 
 public class OlapPropertyKeyClearJob extends IndexLabelRemoveJob {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/SchemaJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/SchemaJob.java
index 0ad9f4f05..ce399fe40 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/SchemaJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/SchemaJob.java
@@ -27,10 +27,9 @@ import org.apache.hugegraph.backend.tx.SchemaTransaction;
 import org.apache.hugegraph.job.SysJob;
 import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.type.HugeType;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class SchemaJob extends SysJob<Object> {
 
@@ -83,21 +82,22 @@ public abstract class SchemaJob extends SysJob<Object> {
     /**
      * Use reflection to call SchemaTransaction.removeSchema(),
      * which is protected
-     * @param tx        The remove operation actual executer
-     * @param schema    the schema to be removed
+     *
+     * @param tx     The remove operation actual executer
+     * @param schema the schema to be removed
      */
     protected static void removeSchema(ISchemaTransaction tx,
                                        SchemaElement schema) {
         try {
-            Method method = ISchemaTransaction.class
-                            .getDeclaredMethod("removeSchema",
-                                               SchemaElement.class);
+            Method method = SchemaTransaction.class
+                    .getDeclaredMethod("removeSchema",
+                                       SchemaElement.class);
             method.setAccessible(true);
             method.invoke(tx, schema);
         } catch (NoSuchMethodException | IllegalAccessException |
                  InvocationTargetException e) {
             throw new AssertionError(
-                      "Can't call SchemaTransaction.removeSchema()", e);
+                    "Can't call SchemaTransaction.removeSchema()", e);
         }
 
     }
@@ -105,21 +105,22 @@ public abstract class SchemaJob extends SysJob<Object> {
     /**
      * Use reflection to call SchemaTransaction.updateSchema(),
      * which is protected
-     * @param tx        The update operation actual execute
-     * @param schema    the schema to be updated
+     *
+     * @param tx     The update operation actual execute
+     * @param schema the schema to be updated
      */
     protected static void updateSchema(SchemaTransaction tx,
                                        SchemaElement schema) {
         try {
             Method method = SchemaTransaction.class
-                            .getDeclaredMethod("updateSchema",
-                                               SchemaElement.class);
+                    .getDeclaredMethod("updateSchema",
+                                       SchemaElement.class);
             method.setAccessible(true);
             method.invoke(tx, schema);
         } catch (NoSuchMethodException | IllegalAccessException |
                  InvocationTargetException e) {
             throw new AssertionError(
-                      "Can't call SchemaTransaction.updateSchema()", e);
+                    "Can't call SchemaTransaction.updateSchema()", e);
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/VertexLabelRemoveJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/VertexLabelRemoveJob.java
index 1bfdfaa68..86c059e8f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/VertexLabelRemoveJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/schema/VertexLabelRemoveJob.java
@@ -20,6 +20,8 @@ package org.apache.hugegraph.job.schema;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
@@ -28,8 +30,7 @@ import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.LockUtil;
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraphParams;
+
 import com.google.common.collect.ImmutableSet;
 
 public class VertexLabelRemoveJob extends SchemaJob {
@@ -64,9 +65,9 @@ public class VertexLabelRemoveJob extends SchemaJob {
         for (EdgeLabel edgeLabel : edgeLabels) {
             if (edgeLabel.linkWithLabel(id)) {
                 throw new HugeException(
-                          "Not allowed to remove vertex label '%s' " +
-                          "because the edge label '%s' still link with it",
-                          vertexLabel.name(), edgeLabel.name());
+                        "Not allowed to remove vertex label '%s' " +
+                        "because the edge label '%s' still link with it",
+                        vertexLabel.name(), edgeLabel.name());
             }
         }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredElementJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredElementJob.java
index 57dcc397e..493bbdde5 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredElementJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredElementJob.java
@@ -19,8 +19,8 @@ package org.apache.hugegraph.job.system;
 
 import java.util.Set;
 
-import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.HugeGraphParams;
+import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.util.E;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredIndexJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredIndexJob.java
index c154716de..5556febb8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredIndexJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredIndexJob.java
@@ -20,12 +20,12 @@ package org.apache.hugegraph.job.system;
 import java.util.Iterator;
 import java.util.Set;
 
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.query.IdQuery;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
-import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.structure.HugeIndex;
+import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
 
 public class DeleteExpiredIndexJob<V> extends DeleteExpiredJob<V> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredJob.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredJob.java
index ca5fed611..9ffa9e955 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredJob.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/DeleteExpiredJob.java
@@ -17,18 +17,17 @@
 
 package org.apache.hugegraph.job.system;
 
-import org.apache.hugegraph.config.CoreOptions;
-import org.apache.hugegraph.task.HugeTask;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.job.EphemeralJob;
 import org.apache.hugegraph.job.EphemeralJobBuilder;
 import org.apache.hugegraph.job.system.JobCounters.JobCounter;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.structure.HugeIndex;
+import org.apache.hugegraph.task.HugeTask;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.slf4j.Logger;
 
 public abstract class DeleteExpiredJob<T> extends EphemeralJob<T> {
 
@@ -77,7 +76,7 @@ public abstract class DeleteExpiredJob<T> extends EphemeralJob<T> {
     }
 
     public static <V> EphemeralJob<V> newDeleteExpiredElementJob(
-                                      JobCounter jobCounter, V object) {
+            JobCounter jobCounter, V object) {
         if (object instanceof HugeElement) {
             return new DeleteExpiredElementJob<>(jobCounter.elements());
         } else {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/JobCounters.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/JobCounters.java
index d117dbe6e..8e7666409 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/JobCounters.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/job/system/JobCounters.java
@@ -21,8 +21,8 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.structure.HugeElement;
 import org.apache.hugegraph.structure.HugeIndex;
 
@@ -90,6 +90,7 @@ public class JobCounters {
 
         /**
          * Try to add element in collection waiting to be deleted
+         *
          * @param element
          * @return true if we should create a new delete job, false otherwise
          */
@@ -103,6 +104,7 @@ public class JobCounters {
 
         /**
          * Try to add edge in collection waiting to be deleted
+         *
          * @param index
          * @return true if we should create a new delete job, false otherwise
          */
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/ClusterRole.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/ClusterRole.java
index 129269362..f85f29cc8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/ClusterRole.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/ClusterRole.java
@@ -87,9 +87,9 @@ public class ClusterRole {
     @Override
     public String toString() {
         return "RoleStateData{" +
-                "node='" + node + '\'' +
-                ", clock=" + clock +
-                ", epoch=" + epoch +
-                '}';
+               "node='" + node + '\'' +
+               ", clock=" + clock +
+               ", epoch=" + epoch +
+               '}';
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/RoleElectionOptions.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/RoleElectionOptions.java
index 9d04d1fc0..748ec36bd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/RoleElectionOptions.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/RoleElectionOptions.java
@@ -23,7 +23,7 @@ import static org.apache.hugegraph.config.OptionChecker.rangeInt;
 import org.apache.hugegraph.config.ConfigOption;
 import org.apache.hugegraph.config.OptionHolder;
 
-public class RoleElectionOptions  extends OptionHolder {
+public class RoleElectionOptions extends OptionHolder {
 
     private RoleElectionOptions() {
         super();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/StandardRoleListener.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/StandardRoleListener.java
index 716cf34e2..dbbea6d91 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/StandardRoleListener.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/masterelection/StandardRoleListener.java
@@ -33,7 +33,7 @@ public class StandardRoleListener implements RoleListener {
 
     private volatile boolean selfIsMaster;
 
-    public StandardRoleListener(TaskManager taskManager, 
+    public StandardRoleListener(TaskManager taskManager,
                                 GlobalMasterInfo roleInfo) {
         this.taskManager = taskManager;
         this.taskManager.enableRoleElection();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphGremlinPlugin.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphGremlinPlugin.java
index e21b3d778..0b3b19ba7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphGremlinPlugin.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphGremlinPlugin.java
@@ -22,13 +22,13 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeFactory;
+import org.apache.hugegraph.util.ReflectionUtil;
 import org.apache.tinkerpop.gremlin.jsr223.AbstractGremlinPlugin;
 import org.apache.tinkerpop.gremlin.jsr223.DefaultImportCustomizer;
 import org.apache.tinkerpop.gremlin.jsr223.ImportCustomizer;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeFactory;
-import org.apache.hugegraph.util.ReflectionUtil;
 import com.google.common.reflect.ClassPath;
 
 public class HugeGraphGremlinPlugin extends AbstractGremlinPlugin {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphPlugin.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphPlugin.java
index d77c4816b..7b7f87653 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphPlugin.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/plugin/HugeGraphPlugin.java
@@ -17,9 +17,9 @@
 
 package org.apache.hugegraph.plugin;
 
-import org.apache.hugegraph.backend.store.BackendProviderFactory;
 import org.apache.hugegraph.analyzer.AnalyzerFactory;
 import org.apache.hugegraph.backend.serializer.SerializerFactory;
+import org.apache.hugegraph.backend.store.BackendProviderFactory;
 import org.apache.hugegraph.config.OptionSpace;
 
 public interface HugeGraphPlugin {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/EdgeLabel.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/EdgeLabel.java
index a1900770b..be8d2d50f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/EdgeLabel.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/EdgeLabel.java
@@ -26,16 +26,16 @@ import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import org.apache.commons.lang3.tuple.Pair;
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.schema.builder.SchemaBuilder;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.EdgeLabelType;
 import org.apache.hugegraph.type.define.Frequency;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.base.Objects;
 
 public class EdgeLabel extends SchemaLabel {
@@ -179,7 +179,7 @@ public class EdgeLabel extends SchemaLabel {
 
     @Override
     public Map<String, Object> asMap() {
-       Map<String, Object> map = new HashMap<>();
+        Map<String, Object> map = new HashMap<>();
 
         if (this.sourceLabel() != null && this.sourceLabel() != NONE_ID) {
             map.put(P.SOURCE_LABEL, this.sourceLabel().asString());
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/IndexLabel.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/IndexLabel.java
index a97ee44e3..e20a728c2 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/IndexLabel.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/IndexLabel.java
@@ -25,14 +25,15 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.schema.builder.SchemaBuilder;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.IndexType;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.base.Objects;
 
 public class IndexLabel extends SchemaElement {
@@ -93,10 +94,10 @@ public class IndexLabel extends SchemaElement {
                 return HugeType.SYS_SCHEMA;
             default:
                 throw new AssertionError(String.format(
-                          "Query type of index label is either '%s' or '%s', " +
-                          "but '%s' is used",
-                          HugeType.VERTEX_LABEL, HugeType.EDGE_LABEL,
-                          this.baseType));
+                        "Query type of index label is either '%s' or '%s', " +
+                        "but '%s' is used",
+                        HugeType.VERTEX_LABEL, HugeType.EDGE_LABEL,
+                        this.baseType));
         }
     }
 
@@ -185,7 +186,7 @@ public class IndexLabel extends SchemaElement {
                 return ILN_IL;
             default:
                 throw new AssertionError(String.format(
-                          "No primitive index label for '%s'", type));
+                        "No primitive index label for '%s'", type));
         }
     }
 
@@ -207,7 +208,7 @@ public class IndexLabel extends SchemaElement {
                     return ILN_IL;
                 default:
                     throw new AssertionError(String.format(
-                              "No primitive index label for '%s'", id));
+                            "No primitive index label for '%s'", id));
             }
         }
         return graph.indexLabel(id);
@@ -243,8 +244,8 @@ public class IndexLabel extends SchemaElement {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported base type '%s' of index label",
-                          baseType));
+                        "Unsupported base type '%s' of index label",
+                        baseType));
         }
 
         E.checkArgumentNotNull(label, "Can't find the %s with name '%s'",
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/PropertyKey.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/PropertyKey.java
index 6198c7e5b..64d5115d8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/PropertyKey.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/PropertyKey.java
@@ -26,9 +26,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.exception.NotSupportException;
 import org.apache.hugegraph.schema.builder.SchemaBuilder;
@@ -145,7 +145,7 @@ public class PropertyKey extends SchemaElement implements Propertiable {
                 return String.format("List<%s>", dataType);
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported cardinality: '%s'", this.cardinality));
+                        "Unsupported cardinality: '%s'", this.cardinality));
         }
     }
 
@@ -165,7 +165,7 @@ public class PropertyKey extends SchemaElement implements Propertiable {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported cardinality: '%s'", this.cardinality));
+                        "Unsupported cardinality: '%s'", this.cardinality));
         }
         return cls;
     }
@@ -192,10 +192,11 @@ public class PropertyKey extends SchemaElement implements Propertiable {
 
     /**
      * Check property value valid
+     *
      * @param value the property value to be checked data type and cardinality
-     * @param <V> the property value class
+     * @param <V>   the property value class
      * @return true if data type and cardinality satisfy requirements,
-     *         otherwise false
+     * otherwise false
      */
     public <V> boolean checkValueType(V value) {
         boolean valid;
@@ -214,17 +215,18 @@ public class PropertyKey extends SchemaElement implements Propertiable {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported cardinality: '%s'", this.cardinality));
+                        "Unsupported cardinality: '%s'", this.cardinality));
         }
         return valid;
     }
 
     /**
      * Check type of the value valid
+     *
      * @param value the property value to be checked data type
      * @param <V>   the property value original data type
      * @return true if the value is or can convert to the data type,
-     *         otherwise false
+     * otherwise false
      */
     private <V> boolean checkDataType(V value) {
         return this.dataType().clazz().isInstance(value);
@@ -232,10 +234,11 @@ public class PropertyKey extends SchemaElement implements Propertiable {
 
     /**
      * Check type of all the values(maybe some list properties) valid
+     *
      * @param values the property values to be checked data type
-     * @param <V> the property value class
+     * @param <V>    the property value class
      * @return true if all the values are or can convert to the data type,
-     *         otherwise false
+     * otherwise false
      */
     private <V> boolean checkDataType(Collection<V> values) {
         boolean valid = true;
@@ -283,8 +286,8 @@ public class PropertyKey extends SchemaElement implements Propertiable {
             return this.convValue(value);
         } catch (RuntimeException e) {
             throw new IllegalArgumentException(String.format(
-                      "Invalid property value '%s' for key '%s': %s",
-                      value, this.name(), e.getMessage()));
+                    "Invalid property value '%s' for key '%s': %s",
+                    value, this.name(), e.getMessage()));
         }
     }
 
@@ -415,7 +418,7 @@ public class PropertyKey extends SchemaElement implements Propertiable {
 
     @Override
     public Map<String, Object> asMap() {
-      Map<String, Object> map = new HashMap<>();
+        Map<String, Object> map = new HashMap<>();
 
         if (this.dataType != null) {
             map.put(P.DATA_TYPE, this.dataType.string());
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaElement.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaElement.java
index 844a7d427..966d3eed8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaElement.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaElement.java
@@ -20,16 +20,16 @@ package org.apache.hugegraph.schema;
 import java.util.Collections;
 import java.util.Map;
 
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.tinkerpop.gremlin.structure.Graph;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.type.Typeable;
 import org.apache.hugegraph.type.define.SchemaStatus;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+
 import com.google.common.base.Objects;
 
 public abstract class SchemaElement implements Nameable, Typeable,
@@ -163,7 +163,7 @@ public abstract class SchemaElement implements Nameable, Typeable,
 
     @Override
     public int hashCode() {
-        return this.type().hashCode() ^  this.id.hashCode();
+        return this.type().hashCode() ^ this.id.hashCode();
     }
 
     @Override
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaLabel.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaLabel.java
index 3a36be69d..e20a3f89d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaLabel.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaLabel.java
@@ -22,18 +22,19 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
-import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.Indexable;
 import org.apache.hugegraph.type.Propertiable;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.base.Objects;
 
 public abstract class SchemaLabel extends SchemaElement
-                                  implements Indexable, Propertiable {
+        implements Indexable, Propertiable {
 
     private final Set<Id> properties;
     private final Set<Id> nullableKeys;
@@ -167,13 +168,13 @@ public abstract class SchemaLabel extends SchemaElement
                 return graph.edgeLabel((String) label).id();
             } else {
                 throw new HugeException(
-                          "Not support query from '%s' with label '%s'",
-                          type, label);
+                        "Not support query from '%s' with label '%s'",
+                        type, label);
             }
         } else {
             throw new HugeException(
-                      "The label type must be number or string, but got '%s'",
-                      label.getClass());
+                    "The label type must be number or string, but got '%s'",
+                    label.getClass());
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaManager.java
index d3851967a..7ea46b0d7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/SchemaManager.java
@@ -20,11 +20,8 @@ package org.apache.hugegraph.schema;
 import java.util.List;
 import java.util.stream.Collectors;
 
-import org.apache.hugegraph.backend.tx.ISchemaTransaction;
-import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.tinkerpop.gremlin.structure.Graph;
-
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.schema.builder.EdgeLabelBuilder;
 import org.apache.hugegraph.schema.builder.IndexLabelBuilder;
@@ -32,6 +29,7 @@ import org.apache.hugegraph.schema.builder.PropertyKeyBuilder;
 import org.apache.hugegraph.schema.builder.VertexLabelBuilder;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.Graph;
 
 public class SchemaManager {
 
@@ -98,26 +96,26 @@ public class SchemaManager {
 
     public List<PropertyKey> getPropertyKeys() {
         return this.graph.propertyKeys().stream()
-                   .filter(pk -> !Graph.Hidden.isHidden(pk.name()))
-                   .collect(Collectors.toList());
+                         .filter(pk -> !Graph.Hidden.isHidden(pk.name()))
+                         .collect(Collectors.toList());
     }
 
     public List<VertexLabel> getVertexLabels() {
         return this.graph.vertexLabels().stream()
-                   .filter(vl -> !Graph.Hidden.isHidden(vl.name()))
-                   .collect(Collectors.toList());
+                         .filter(vl -> !Graph.Hidden.isHidden(vl.name()))
+                         .collect(Collectors.toList());
     }
 
     public List<EdgeLabel> getEdgeLabels() {
         return this.graph.edgeLabels().stream()
-                   .filter(el -> !Graph.Hidden.isHidden(el.name()))
-                   .collect(Collectors.toList());
+                         .filter(el -> !Graph.Hidden.isHidden(el.name()))
+                         .collect(Collectors.toList());
     }
 
     public List<IndexLabel> getIndexLabels() {
         return this.graph.indexLabels().stream()
-                   .filter(il -> !Graph.Hidden.isHidden(il.name()))
-                   .collect(Collectors.toList());
+                         .filter(il -> !Graph.Hidden.isHidden(il.name()))
+                         .collect(Collectors.toList());
     }
 
     public void copyFrom(SchemaManager schema) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/Userdata.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/Userdata.java
index a3d2f6356..d485e558b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/Userdata.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/Userdata.java
@@ -47,8 +47,8 @@ public class Userdata extends HashMap<String, Object> {
                 for (Map.Entry<String, Object> e : userdata.entrySet()) {
                     if (e.getValue() == null) {
                         throw new NotAllowException(
-                                  "Not allowed to pass null userdata value " +
-                                  "when create or append schema");
+                                "Not allowed to pass null userdata value " +
+                                "when create or append schema");
                     }
                 }
                 break;
@@ -58,7 +58,7 @@ public class Userdata extends HashMap<String, Object> {
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema action '%s'", action));
+                        "Unknown schema action '%s'", action));
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/VertexLabel.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/VertexLabel.java
index bfdd1439e..3f62df863 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/VertexLabel.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/VertexLabel.java
@@ -26,9 +26,9 @@ import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.schema.builder.SchemaBuilder;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.IdStrategy;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/AbstractBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/AbstractBuilder.java
index be13ea528..fc01f0afe 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/AbstractBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/AbstractBuilder.java
@@ -20,17 +20,17 @@ package org.apache.hugegraph.schema.builder;
 import java.util.Set;
 import java.util.function.Function;
 
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
+import org.apache.hugegraph.exception.ExistedException;
+import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.exception.ExistedException;
-import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.GraphMode;
 import org.apache.hugegraph.type.define.SchemaStatus;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/EdgeLabelBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/EdgeLabelBuilder.java
index 7c26f1839..f7aa460e1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/EdgeLabelBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/EdgeLabelBuilder.java
@@ -26,28 +26,28 @@ import java.util.Map;
 import java.util.Set;
 
 import org.apache.commons.collections.CollectionUtils;
-
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.hugegraph.schema.PropertyKey;
-import org.apache.hugegraph.schema.Userdata;
-import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.exception.NotAllowException;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.schema.EdgeLabel;
+import org.apache.hugegraph.schema.PropertyKey;
+import org.apache.hugegraph.schema.Userdata;
+import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Action;
 import org.apache.hugegraph.type.define.Frequency;
 import org.apache.hugegraph.util.CollectionUtil;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.collect.ImmutableList;
 
 public class EdgeLabelBuilder extends AbstractBuilder
-                              implements EdgeLabel.Builder {
+        implements EdgeLabel.Builder {
 
     private Id id;
     private String name;
@@ -115,7 +115,7 @@ public class EdgeLabelBuilder extends AbstractBuilder
         edgeLabel.ttl(this.ttl);
         if (this.ttlStartTime != null) {
             edgeLabel.ttlStartTime(this.graph().propertyKey(
-                                   this.ttlStartTime).id());
+                    this.ttlStartTime).id());
         }
         edgeLabel.enableLabelIndex(this.enableLabelIndex == null ||
                                    this.enableLabelIndex);
@@ -171,6 +171,7 @@ public class EdgeLabelBuilder extends AbstractBuilder
      * Only sourceId, targetId, frequency, enableLabelIndex, properties, sortKeys,
      * nullableKeys are checked.
      * The id, ttl, ttlStartTime, userdata are not checked.
+     *
      * @param existedEdgeLabel to be compared with
      * @return true if this has same properties with existedVertexLabel
      */
@@ -427,15 +428,15 @@ public class EdgeLabelBuilder extends AbstractBuilder
             case ELIMINATE:
                 if (!this.properties.isEmpty()) {
                     throw new NotAllowException(
-                              "Not support to eliminate properties " +
-                              "for edge label currently");
+                            "Not support to eliminate properties " +
+                            "for edge label currently");
                 }
                 break;
             case DELETE:
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema action '%s'", action));
+                        "Unknown schema action '%s'", action));
         }
     }
 
@@ -445,8 +446,8 @@ public class EdgeLabelBuilder extends AbstractBuilder
         if (action == Action.ELIMINATE) {
             if (!this.nullableKeys.isEmpty()) {
                 throw new NotAllowException(
-                          "Not support to eliminate nullableKeys " +
-                          "for edge label currently");
+                        "Not support to eliminate nullableKeys " +
+                        "for edge label currently");
             }
             return;
         }
@@ -460,7 +461,7 @@ public class EdgeLabelBuilder extends AbstractBuilder
         Set<String> appendProps = this.properties;
 
         E.checkArgument(CollectionUtil.union(originProps, appendProps)
-                        .containsAll(this.nullableKeys),
+                                      .containsAll(this.nullableKeys),
                         "The nullableKeys: %s to be created or appended " +
                         "must belong to the origin/new properties: %s/%s ",
                         this.nullableKeys, originProps, appendProps);
@@ -477,7 +478,7 @@ public class EdgeLabelBuilder extends AbstractBuilder
 
         if (action == Action.APPEND) {
             Collection<String> newAddedProps = CollectionUtils.subtract(
-                                               appendProps, originProps);
+                    appendProps, originProps);
             E.checkArgument(this.nullableKeys.containsAll(newAddedProps),
                             "The new added properties: %s must be nullable",
                             newAddedProps);
@@ -535,28 +536,28 @@ public class EdgeLabelBuilder extends AbstractBuilder
     private void checkStableVars() {
         if (this.sourceLabel != null) {
             throw new NotAllowException(
-                      "Not allowed to update source label " +
-                      "for edge label '%s', it must be null", this.name);
+                    "Not allowed to update source label " +
+                    "for edge label '%s', it must be null", this.name);
         }
         if (this.targetLabel != null) {
             throw new NotAllowException(
-                      "Not allowed to update target label " +
-                      "for edge label '%s', it must be null", this.name);
+                    "Not allowed to update target label " +
+                    "for edge label '%s', it must be null", this.name);
         }
         if (this.frequency != Frequency.DEFAULT) {
             throw new NotAllowException(
-                      "Not allowed to update frequency " +
-                      "for edge label '%s'", this.name);
+                    "Not allowed to update frequency " +
+                    "for edge label '%s'", this.name);
         }
         if (!this.sortKeys.isEmpty()) {
             throw new NotAllowException(
-                      "Not allowed to update sort keys " +
-                      "for edge label '%s'", this.name);
+                    "Not allowed to update sort keys " +
+                    "for edge label '%s'", this.name);
         }
         if (this.enableLabelIndex != null) {
             throw new NotAllowException(
-                      "Not allowed to update enable_label_index " +
-                      "for edge label '%s'", this.name);
+                    "Not allowed to update enable_label_index " +
+                    "for edge label '%s'", this.name);
         }
     }
 
@@ -601,8 +602,8 @@ public class EdgeLabelBuilder extends AbstractBuilder
                 for (Map.Entry<String, Object> e : this.userdata.entrySet()) {
                     if (e.getValue() == null) {
                         throw new NotAllowException(
-                                  "Not allowed pass null userdata value when " +
-                                  "create or append edge label");
+                                "Not allowed pass null userdata value when " +
+                                "create or append edge label");
                     }
                 }
                 break;
@@ -612,7 +613,7 @@ public class EdgeLabelBuilder extends AbstractBuilder
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema action '%s'", action));
+                        "Unknown schema action '%s'", action));
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/IndexLabelBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/IndexLabelBuilder.java
index db758b10e..2ca3534a9 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/IndexLabelBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/IndexLabelBuilder.java
@@ -25,12 +25,12 @@ import java.util.Set;
 import java.util.concurrent.TimeoutException;
 import java.util.function.BiPredicate;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.exception.NotAllowException;
@@ -53,7 +53,7 @@ import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.collection.IdSet;
 
 public class IndexLabelBuilder extends AbstractBuilder
-                               implements IndexLabel.Builder {
+        implements IndexLabel.Builder {
 
     private Id id;
     private String name;
@@ -125,6 +125,7 @@ public class IndexLabelBuilder extends AbstractBuilder
      * Check whether this has same properties with existedIndexLabel.
      * Only baseType, baseValue, indexType, indexFields are checked.
      * The id, checkExist, userdata are not checked.
+     *
      * @param existedIndexLabel to be compared with
      * @return true if this has same properties with existedIndexLabel
      */
@@ -269,7 +270,7 @@ public class IndexLabelBuilder extends AbstractBuilder
             graph.taskScheduler().waitUntilTaskCompleted(task, timeout);
         } catch (TimeoutException e) {
             throw new HugeException(
-                      "Failed to wait index-creating task completed", e);
+                    "Failed to wait index-creating task completed", e);
         }
 
         // Return index label without task-info
@@ -588,7 +589,7 @@ public class IndexLabelBuilder extends AbstractBuilder
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unsupported index type: %s", this.indexType));
+                        "Unsupported index type: %s", this.indexType));
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/PropertyKeyBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/PropertyKeyBuilder.java
index 98be4998d..6ce6ddd84 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/PropertyKeyBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/PropertyKeyBuilder.java
@@ -20,20 +20,20 @@ package org.apache.hugegraph.schema.builder;
 import java.util.Map;
 import java.util.concurrent.TimeoutException;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.hugegraph.schema.PropertyKey;
-import org.apache.hugegraph.schema.SchemaElement;
-import org.apache.hugegraph.schema.Userdata;
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.exception.NotAllowException;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.exception.NotSupportException;
+import org.apache.hugegraph.schema.PropertyKey;
+import org.apache.hugegraph.schema.SchemaElement;
+import org.apache.hugegraph.schema.Userdata;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Action;
 import org.apache.hugegraph.type.define.AggregateType;
@@ -43,7 +43,7 @@ import org.apache.hugegraph.type.define.WriteType;
 import org.apache.hugegraph.util.E;
 
 public class PropertyKeyBuilder extends AbstractBuilder
-                                implements PropertyKey.Builder {
+        implements PropertyKey.Builder {
 
     private Id id;
     private String name;
@@ -99,6 +99,7 @@ public class PropertyKeyBuilder extends AbstractBuilder
      * Check whether this has same properties with propertyKey.
      * Only dataType, cardinality, aggregateType are checked.
      * The id, checkExist, userdata are not checked.
+     *
      * @param propertyKey to be compared with
      * @return true if this has same properties with propertyKey
      */
@@ -118,12 +119,9 @@ public class PropertyKeyBuilder extends AbstractBuilder
             return false;
         }
 
-        if (this.writeType != propertyKey.writeType()) {
-            return false;
-        }
+        return this.writeType == propertyKey.writeType();
 
         // all properties are same, return true.
-        return true;
     }
 
     @Override
@@ -157,7 +155,7 @@ public class PropertyKeyBuilder extends AbstractBuilder
     public PropertyKey create() {
         // Create index label async
         SchemaElement.TaskWithSchema propertyKeyWithTask =
-                                     this.createWithTask();
+                this.createWithTask();
 
         Id task = propertyKeyWithTask.task();
         if (task == IdGenerator.ZERO) {
@@ -175,7 +173,7 @@ public class PropertyKeyBuilder extends AbstractBuilder
             graph.taskScheduler().waitUntilTaskCompleted(task, timeout);
         } catch (TimeoutException e) {
             throw new HugeException(
-                      "Failed to wait property key create task completed", e);
+                    "Failed to wait property key create task completed", e);
         }
 
         // Return property key without task-info
@@ -425,17 +423,17 @@ public class PropertyKeyBuilder extends AbstractBuilder
 
         if (this.aggregateType.isSum() && this.dataType.isDate()) {
             throw new NotAllowException(
-                      "Not allowed to set aggregate type '%s' for " +
-                      "property key '%s' with data type '%s'",
-                      this.aggregateType, this.name, this.dataType);
+                    "Not allowed to set aggregate type '%s' for " +
+                    "property key '%s' with data type '%s'",
+                    this.aggregateType, this.name, this.dataType);
         }
 
         if (this.aggregateType.isNumber() &&
             !this.dataType.isNumber() && !this.dataType.isDate()) {
             throw new NotAllowException(
-                      "Not allowed to set aggregate type '%s' for " +
-                      "property key '%s' with data type '%s'",
-                      this.aggregateType, this.name, this.dataType);
+                    "Not allowed to set aggregate type '%s' for " +
+                    "property key '%s' with data type '%s'",
+                    this.aggregateType, this.name, this.dataType);
         }
     }
 
@@ -446,22 +444,22 @@ public class PropertyKeyBuilder extends AbstractBuilder
 
         if (!this.graph().backendStoreFeatures().supportsOlapProperties()) {
             throw new NotSupportException(
-                      "olap property key '%s' for backend '%s'",
-                      this.name, this.graph().backend());
+                    "olap property key '%s' for backend '%s'",
+                    this.name, this.graph().backend());
         }
 
         if (!this.aggregateType.isNone()) {
             throw new NotAllowException(
-                      "Not allowed to set aggregate type '%s' for olap " +
-                      "property key '%s'", this.aggregateType, this.name);
+                    "Not allowed to set aggregate type '%s' for olap " +
+                    "property key '%s'", this.aggregateType, this.name);
         }
 
         if (this.writeType == WriteType.OLAP_RANGE &&
             !this.dataType.isNumber() && !this.dataType.isDate()) {
             throw new NotAllowException(
-                      "Not allowed to set write type to OLAP_RANGE for " +
-                      "property key '%s' with data type '%s'",
-                      this.name, this.dataType);
+                    "Not allowed to set write type to OLAP_RANGE for " +
+                    "property key '%s' with data type '%s'",
+                    this.name, this.dataType);
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/VertexLabelBuilder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/VertexLabelBuilder.java
index 7704756db..daa460b7a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/VertexLabelBuilder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/schema/builder/VertexLabelBuilder.java
@@ -26,27 +26,27 @@ import java.util.Map;
 import java.util.Set;
 
 import org.apache.commons.collections.CollectionUtils;
-
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.tx.ISchemaTransaction;
 import org.apache.hugegraph.backend.tx.SchemaTransaction;
-import org.apache.hugegraph.schema.PropertyKey;
-import org.apache.hugegraph.schema.Userdata;
-import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.exception.ExistedException;
 import org.apache.hugegraph.exception.NotAllowException;
 import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.schema.PropertyKey;
+import org.apache.hugegraph.schema.Userdata;
+import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Action;
 import org.apache.hugegraph.type.define.IdStrategy;
 import org.apache.hugegraph.util.CollectionUtil;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.collect.ImmutableList;
 
 public class VertexLabelBuilder extends AbstractBuilder
-                                implements VertexLabel.Builder {
+        implements VertexLabel.Builder {
 
     private Id id;
     private String name;
@@ -106,7 +106,7 @@ public class VertexLabelBuilder extends AbstractBuilder
         vertexLabel.ttl(this.ttl);
         if (this.ttlStartTime != null) {
             vertexLabel.ttlStartTime(this.graph().propertyKey(
-                                     this.ttlStartTime).id());
+                    this.ttlStartTime).id());
         }
         // Assign properties
         for (String key : this.properties) {
@@ -158,6 +158,7 @@ public class VertexLabelBuilder extends AbstractBuilder
      * Check whether this has same properties with existedVertexLabel.
      * Only properties, primaryKeys, nullableKeys, enableLabelIndex are checked.
      * The id, idStrategy, checkExist, userdata are not checked.
+     *
      * @param existedVertexLabel to be compared with
      * @return true if this has same properties with existedVertexLabel
      */
@@ -417,15 +418,15 @@ public class VertexLabelBuilder extends AbstractBuilder
             case ELIMINATE:
                 if (!this.properties.isEmpty()) {
                     throw new NotAllowException(
-                              "Not support to eliminate properties " +
-                              "for vertex label currently");
+                            "Not support to eliminate properties " +
+                            "for vertex label currently");
                 }
                 break;
             case DELETE:
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema action '%s'", action));
+                        "Unknown schema action '%s'", action));
         }
     }
 
@@ -435,8 +436,8 @@ public class VertexLabelBuilder extends AbstractBuilder
         if (action == Action.ELIMINATE) {
             if (!this.nullableKeys.isEmpty()) {
                 throw new NotAllowException(
-                          "Not support to eliminate nullableKeys " +
-                          "for vertex label currently");
+                        "Not support to eliminate nullableKeys " +
+                        "for vertex label currently");
             }
             return;
         }
@@ -467,7 +468,7 @@ public class VertexLabelBuilder extends AbstractBuilder
 
         if (action == Action.APPEND) {
             Collection<String> newAddedProps = CollectionUtils.subtract(
-                                               appendProps, originProps);
+                    appendProps, originProps);
             E.checkArgument(this.nullableKeys.containsAll(newAddedProps),
                             "The new added properties: %s must be nullable",
                             newAddedProps);
@@ -500,7 +501,7 @@ public class VertexLabelBuilder extends AbstractBuilder
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown id strategy '%s'", strategy));
+                        "Unknown id strategy '%s'", strategy));
         }
         if (this.idStrategy == IdStrategy.PRIMARY_KEY) {
             this.checkPrimaryKeys();
@@ -532,18 +533,18 @@ public class VertexLabelBuilder extends AbstractBuilder
     private void checkStableVars() {
         if (!this.primaryKeys.isEmpty()) {
             throw new NotAllowException(
-                      "Not allowed to update primary keys " +
-                      "for vertex label '%s'", this.name);
+                    "Not allowed to update primary keys " +
+                    "for vertex label '%s'", this.name);
         }
         if (this.idStrategy != IdStrategy.DEFAULT) {
             throw new NotAllowException(
-                      "Not allowed to update id strategy " +
-                      "for vertex label '%s'", this.name);
+                    "Not allowed to update id strategy " +
+                    "for vertex label '%s'", this.name);
         }
         if (this.enableLabelIndex != null) {
             throw new NotAllowException(
-                      "Not allowed to update enable_label_index " +
-                      "for vertex label '%s'", this.name);
+                    "Not allowed to update enable_label_index " +
+                    "for vertex label '%s'", this.name);
         }
     }
 
@@ -579,8 +580,8 @@ public class VertexLabelBuilder extends AbstractBuilder
                 for (Map.Entry<String, Object> e : this.userdata.entrySet()) {
                     if (e.getValue() == null) {
                         throw new NotAllowException(
-                                  "Not allowed pass null userdata value when " +
-                                  "create or append edge label");
+                                "Not allowed pass null userdata value when " +
+                                "create or append edge label");
                     }
                 }
                 break;
@@ -590,7 +591,7 @@ public class VertexLabelBuilder extends AbstractBuilder
                 break;
             default:
                 throw new AssertionError(String.format(
-                          "Unknown schema action '%s'", action));
+                        "Unknown schema action '%s'", action));
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/security/HugeSecurityManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/security/HugeSecurityManager.java
index e83959113..7c4f33c54 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/security/HugeSecurityManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/security/HugeSecurityManager.java
@@ -24,9 +24,9 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArraySet;
 
+import org.apache.hugegraph.util.Log;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.util.Log;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 
@@ -35,9 +35,9 @@ public class HugeSecurityManager extends SecurityManager {
     private static final String USER_DIR = System.getProperty("user.dir");
 
     private static final String USER_DIR_IDE =
-                                USER_DIR.endsWith("hugegraph-dist") ?
-                                USER_DIR.substring(0, USER_DIR.length() - 15) :
-                                null;
+            USER_DIR.endsWith("hugegraph-dist") ?
+            USER_DIR.substring(0, USER_DIR.length() - 15) :
+            null;
 
     private static final String GREMLIN_SERVER_WORKER = "gremlin-server-exec";
     private static final String TASK_WORKER = "task-worker";
@@ -49,7 +49,6 @@ public class HugeSecurityManager extends SecurityManager {
     private static final Set<String> DENIED_PERMISSIONS = ImmutableSet.of("setSecurityManager");
 
 
-
     private static final Set<String> ACCEPT_CLASS_LOADERS = ImmutableSet.of(
             "groovy.lang.GroovyClassLoader",
             "sun.reflect.DelegatingClassLoader",
@@ -132,7 +131,7 @@ public class HugeSecurityManager extends SecurityManager {
     public static void ignoreCheckedClass(String clazz) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to add ignore check via Gremlin");
+                    "Not allowed to add ignore check via Gremlin");
         }
 
         IGNORE_CHECKED_CLASSES.add(clazz);
@@ -143,7 +142,7 @@ public class HugeSecurityManager extends SecurityManager {
         if (DENIED_PERMISSIONS.contains(permission.getName()) &&
             callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to access denied permission via Gremlin");
+                    "Not allowed to access denied permission via Gremlin");
         }
     }
 
@@ -152,7 +151,7 @@ public class HugeSecurityManager extends SecurityManager {
         if (DENIED_PERMISSIONS.contains(permission.getName()) &&
             callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to access denied permission via Gremlin");
+                    "Not allowed to access denied permission via Gremlin");
         }
     }
 
@@ -160,7 +159,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkCreateClassLoader() {
         if (!callFromAcceptClassLoaders() && callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to create class loader via Gremlin");
+                    "Not allowed to create class loader via Gremlin");
         }
         super.checkCreateClassLoader();
     }
@@ -169,7 +168,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkLink(String lib) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to link library via Gremlin");
+                    "Not allowed to link library via Gremlin");
         }
         super.checkLink(lib);
     }
@@ -181,7 +180,7 @@ public class HugeSecurityManager extends SecurityManager {
             !callFromBackendThread() && !callFromBackendHbase() &&
             !callFromRaft() && !callFromSofaRpc() && !callFromIgnoreCheckedClass()) {
             throw newSecurityException(
-                  "Not allowed to access thread via Gremlin");
+                    "Not allowed to access thread via Gremlin");
         }
         super.checkAccess(thread);
     }
@@ -194,7 +193,7 @@ public class HugeSecurityManager extends SecurityManager {
             !callFromRaft() && !callFromSofaRpc() &&
             !callFromIgnoreCheckedClass()) {
             throw newSecurityException(
-                  "Not allowed to access thread group via Gremlin");
+                    "Not allowed to access thread group via Gremlin");
         }
         super.checkAccess(threadGroup);
     }
@@ -203,7 +202,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkExit(int status) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to call System.exit() via Gremlin");
+                    "Not allowed to call System.exit() via Gremlin");
         }
         super.checkExit(status);
     }
@@ -212,7 +211,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkExec(String cmd) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to execute command via Gremlin");
+                    "Not allowed to execute command via Gremlin");
         }
         super.checkExec(cmd);
     }
@@ -233,7 +232,7 @@ public class HugeSecurityManager extends SecurityManager {
             !callFromSnapshot() && !callFromRaft() &&
             !callFromSofaRpc()) {
             throw newSecurityException(
-                  "Not allowed to read file via Gremlin: %s", file);
+                    "Not allowed to read file via Gremlin: %s", file);
         }
         super.checkRead(file);
     }
@@ -242,7 +241,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkRead(String file, Object context) {
         if (callFromGremlin() && !callFromRaft() && !callFromSofaRpc()) {
             throw newSecurityException(
-                  "Not allowed to read file via Gremlin: %s", file);
+                    "Not allowed to read file via Gremlin: %s", file);
         }
         super.checkRead(file, context);
     }
@@ -269,7 +268,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkDelete(String file) {
         if (callFromGremlin() && !callFromSnapshot()) {
             throw newSecurityException(
-                  "Not allowed to delete file via Gremlin");
+                    "Not allowed to delete file via Gremlin");
         }
         super.checkDelete(file);
     }
@@ -278,7 +277,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkListen(int port) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to listen socket via Gremlin");
+                    "Not allowed to listen socket via Gremlin");
         }
         super.checkListen(port);
     }
@@ -287,7 +286,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkAccept(String host, int port) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to accept socket via Gremlin");
+                    "Not allowed to accept socket via Gremlin");
         }
         super.checkAccept(host, port);
     }
@@ -297,7 +296,7 @@ public class HugeSecurityManager extends SecurityManager {
         if (callFromGremlin() && !callFromBackendSocket() &&
             !callFromBackendHbase() && !callFromRaft() && !callFromSofaRpc()) {
             throw newSecurityException(
-                  "Not allowed to connect socket via Gremlin");
+                    "Not allowed to connect socket via Gremlin");
         }
         super.checkConnect(host, port);
     }
@@ -306,7 +305,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkConnect(String host, int port, Object context) {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to connect socket via Gremlin");
+                    "Not allowed to connect socket via Gremlin");
         }
         super.checkConnect(host, port, context);
     }
@@ -332,7 +331,7 @@ public class HugeSecurityManager extends SecurityManager {
     public void checkSetFactory() {
         if (callFromGremlin()) {
             throw newSecurityException(
-                  "Not allowed to set socket factory via Gremlin");
+                    "Not allowed to set socket factory via Gremlin");
         }
         super.checkSetFactory();
     }
@@ -342,7 +341,7 @@ public class HugeSecurityManager extends SecurityManager {
         if (callFromGremlin() && !callFromSofaRpc() &&
             !callFromNewSecurityException()) {
             throw newSecurityException(
-                  "Not allowed to access system properties via Gremlin");
+                    "Not allowed to access system properties via Gremlin");
         }
         super.checkPropertiesAccess();
     }
@@ -354,7 +353,7 @@ public class HugeSecurityManager extends SecurityManager {
             !callFromSnapshot() && !callFromRaft() &&
             !callFromSofaRpc()) {
             throw newSecurityException(
-                  "Not allowed to access system property(%s) via Gremlin", key);
+                    "Not allowed to access system property(%s) via Gremlin", key);
         }
         super.checkPropertyAccess(key);
     }
@@ -398,12 +397,9 @@ public class HugeSecurityManager extends SecurityManager {
     }
 
     private static boolean readGroovyInCurrentDir(String file) {
-        if (file != null && (USER_DIR != null && file.startsWith(USER_DIR) ||
-            USER_DIR_IDE != null && file.startsWith(USER_DIR_IDE)) &&
-            (file.endsWith(".class") || file.endsWith(".groovy"))) {
-            return true;
-        }
-        return false;
+        return file != null && (USER_DIR != null && file.startsWith(USER_DIR) ||
+                                USER_DIR_IDE != null && file.startsWith(USER_DIR_IDE)) &&
+               (file.endsWith(".class") || file.endsWith(".groovy"));
     }
 
     private static boolean callFromGremlin() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/GraphType.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/GraphType.java
index 174c8e7de..7cf5ee3b4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/GraphType.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/GraphType.java
@@ -21,4 +21,5 @@ import org.apache.hugegraph.type.Nameable;
 import org.apache.hugegraph.type.Typeable;
 
 public interface GraphType extends Nameable, Typeable {
+
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdge.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdge.java
index b14802be4..53b8a5493 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdge.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdge.java
@@ -27,7 +27,9 @@ import org.apache.hugegraph.backend.id.EdgeId;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.QueryResults;
+import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
+import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
@@ -35,16 +37,13 @@ import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.type.define.HugeKeys;
+import org.apache.hugegraph.util.E;
 import org.apache.logging.log4j.util.Strings;
 import org.apache.tinkerpop.gremlin.structure.Direction;
 import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
-
-import org.apache.hugegraph.backend.serializer.BytesBuffer;
-import org.apache.hugegraph.perf.PerfUtil.Watched;
-import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.util.empty.EmptyProperty;
 
 import com.google.common.collect.ImmutableList;
@@ -463,6 +462,7 @@ public class HugeEdge extends HugeElement implements Edge, Cloneable {
 
     /**
      * Clear properties of the edge, and set `removed` true
+     *
      * @return a new edge
      */
     public HugeEdge prepareRemoved() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdgeProperty.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdgeProperty.java
index 6f78c0da7..f89e4f0cf 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdgeProperty.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeEdgeProperty.java
@@ -47,7 +47,7 @@ public class HugeEdgeProperty<V> extends HugeProperty<V> {
         assert this.owner instanceof HugeEdge;
         EdgeLabel edgeLabel = ((HugeEdge) this.owner).schemaLabel();
         E.checkArgument(edgeLabel.nullableKeys().contains(
-                        this.propertyKey().id()),
+                                this.propertyKey().id()),
                         "Can't remove non-null edge property '%s'", this);
         this.owner.graph().removeEdgeProperty(this);
     }
@@ -60,6 +60,7 @@ public class HugeEdgeProperty<V> extends HugeProperty<V> {
         return ElementHelper.areEqual(this, obj);
     }
 
+    @Override
     public int hashCode() {
         return ElementHelper.hashCode(this);
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeElement.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeElement.java
index a7c93333f..f727dc2fc 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeElement.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeElement.java
@@ -46,7 +46,6 @@ import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.InsertionOrderUtil;
 import org.apache.hugegraph.util.collection.CollectionFactory;
 import org.apache.tinkerpop.gremlin.structure.Element;
-import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.util.ElementHelper;
 import org.eclipse.collections.api.iterator.IntIterator;
@@ -55,7 +54,7 @@ import org.eclipse.collections.api.map.primitive.MutableIntObjectMap;
 public abstract class HugeElement implements Element, GraphType, Idfiable, Comparable<HugeElement> {
 
     private static final MutableIntObjectMap<HugeProperty<?>> EMPTY_MAP =
-                         CollectionFactory.newIntObjectMap();
+            CollectionFactory.newIntObjectMap();
     private static final int MAX_PROPERTIES = BytesBuffer.UINT16_MAX;
 
     private final HugeGraph graph;
@@ -329,7 +328,7 @@ public abstract class HugeElement implements Element, GraphType, Idfiable, Compa
     }
 
     @Watched(prefix = "element")
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     private <V> HugeProperty<V> addProperty(PropertyKey pkey, V value,
                                             Supplier<Collection<V>> supplier) {
         assert pkey.cardinality().multiple();
@@ -372,7 +371,7 @@ public abstract class HugeElement implements Element, GraphType, Idfiable, Compa
             this.properties = EMPTY_MAP;
         } else {
             this.properties = CollectionFactory.newIntObjectMap(
-                              element.properties);
+                    element.properties);
         }
         this.propLoaded = true;
     }
@@ -414,8 +413,9 @@ public abstract class HugeElement implements Element, GraphType, Idfiable, Compa
 
     /**
      * Classify parameter list(pairs) from call request
+     *
      * @param keyValues The property key-value pair of the vertex or edge
-     * @return          Key-value pairs that are classified and processed
+     * @return Key-value pairs that are classified and processed
      */
     @Watched(prefix = "element")
     public static final ElementKeys classifyKeys(Object... keyValues) {
@@ -488,8 +488,8 @@ public abstract class HugeElement implements Element, GraphType, Idfiable, Compa
 
         // Throw if error type
         throw new UnsupportedOperationException(String.format(
-                  "Invalid element id: %s(%s)",
-                  idValue, idValue.getClass().getSimpleName()));
+                "Invalid element id: %s(%s)",
+                idValue, idValue.getClass().getSimpleName()));
     }
 
     @Watched(prefix = "element")
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeFeatures.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeFeatures.java
index ec1c216a1..f8bdb8c75 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeFeatures.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeFeatures.java
@@ -67,7 +67,7 @@ public class HugeFeatures implements Graph.Features {
     public class HugeGraphFeatures implements GraphFeatures {
 
         private final VariableFeatures variableFeatures =
-                                       new HugeVariableFeatures();
+                new HugeVariableFeatures();
 
         @Override
         public boolean supportsConcurrentAccess() {
@@ -157,12 +157,12 @@ public class HugeFeatures implements Graph.Features {
     }
 
     public class HugeVariableFeatures extends HugeDataTypeFeatures
-                                      implements VariableFeatures {
+            implements VariableFeatures {
 
     }
 
     public class HugeVertexPropertyFeatures extends HugeDataTypeFeatures
-                                            implements VertexPropertyFeatures {
+            implements VertexPropertyFeatures {
 
         @Override
         public boolean supportsRemoveProperty() {
@@ -206,7 +206,7 @@ public class HugeFeatures implements Graph.Features {
     }
 
     public class HugeEdgePropertyFeatures extends HugeDataTypeFeatures
-                                          implements EdgePropertyFeatures {
+            implements EdgePropertyFeatures {
 
         @Override
         public boolean supportsMapValues() {
@@ -231,10 +231,10 @@ public class HugeFeatures implements Graph.Features {
     }
 
     public class HugeVertexFeatures extends HugeElementFeatures
-                                    implements VertexFeatures {
+            implements VertexFeatures {
 
         private final VertexPropertyFeatures vertexPropertyFeatures =
-                                             new HugeVertexPropertyFeatures();
+                new HugeVertexPropertyFeatures();
 
         @Override
         public boolean supportsUserSuppliedIds() {
@@ -280,15 +280,15 @@ public class HugeFeatures implements Graph.Features {
 
         public String defaultLabel() {
             return HugeFeatures.this.graph
-                               .option(CoreOptions.VERTEX_DEFAULT_LABEL);
+                    .option(CoreOptions.VERTEX_DEFAULT_LABEL);
         }
     }
 
     public class HugeEdgeFeatures extends HugeElementFeatures
-                                  implements EdgeFeatures {
+            implements EdgeFeatures {
 
         private final EdgePropertyFeatures edgePropertyFeatures =
-                                           new HugeEdgePropertyFeatures();
+                new HugeEdgePropertyFeatures();
 
         @Override
         public EdgePropertyFeatures properties() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeIndex.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeIndex.java
index 05eff56bb..fa442e129 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeIndex.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeIndex.java
@@ -28,11 +28,11 @@ import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.Id.IdType;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.backend.id.SplicingIdGenerator;
+import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.SchemaElement;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.DataType;
-import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.HashUtil;
 import org.apache.hugegraph.util.InsertionOrderUtil;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeProperty.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeProperty.java
index 85990d2af..cc96bd27b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeProperty.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeProperty.java
@@ -22,12 +22,11 @@ import java.util.NoSuchElementException;
 import org.apache.hugegraph.backend.id.SplicingIdGenerator;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.type.HugeType;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.util.ElementHelper;
 import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
 
-import org.apache.hugegraph.util.E;
-
 public abstract class HugeProperty<V> implements Property<V>, GraphType {
 
     protected final HugeElement owner;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertex.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertex.java
index ad0f4c083..b5223125d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertex.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertex.java
@@ -305,7 +305,7 @@ public class HugeVertex extends HugeElement implements Vertex, Cloneable {
         EdgeLabel edgeLabel = this.graph().edgeLabel(label);
         // Check link
         E.checkArgument(edgeLabel.checkLinkEqual(this.schemaLabel().id(),
-                        vertex.schemaLabel().id()),
+                                                 vertex.schemaLabel().id()),
                         "Undefined link of edge label '%s': '%s' -> '%s'",
                         label, this.label(), vertex.label());
         // Check sortKeys
@@ -317,14 +317,14 @@ public class HugeVertex extends HugeElement implements Vertex, Cloneable {
         // Check whether passed all non-null props
         @SuppressWarnings("unchecked")
         Collection<Id> nonNullKeys = CollectionUtils.subtract(
-                                     edgeLabel.properties(),
-                                     edgeLabel.nullableKeys());
+                edgeLabel.properties(),
+                edgeLabel.nullableKeys());
         if (!new HashSet<>(keys).containsAll(nonNullKeys)) {
             @SuppressWarnings("unchecked")
             Collection<Id> missed = CollectionUtils.subtract(nonNullKeys, keys);
             E.checkArgument(false, "All non-null property keys: %s " +
-                            "of edge label '%s' must be set, " +
-                            "but missed keys: %s",
+                                   "of edge label '%s' must be set, " +
+                                   "but missed keys: %s",
                             this.graph().mapPkId2Name(nonNullKeys),
                             edgeLabel.name(),
                             this.graph().mapPkId2Name(missed));
@@ -341,6 +341,7 @@ public class HugeVertex extends HugeElement implements Vertex, Cloneable {
 
     /**
      * Add edge with direction OUT
+     *
      * @param edge the out edge
      */
     @Watched
@@ -356,6 +357,7 @@ public class HugeVertex extends HugeElement implements Vertex, Cloneable {
 
     /**
      * Add edge with direction IN
+     *
      * @param edge the in edge
      */
     @Watched
@@ -613,6 +615,7 @@ public class HugeVertex extends HugeElement implements Vertex, Cloneable {
 
     /**
      * Clear edges/properties of the cloned vertex, and set `removed` true
+     *
      * @return a new vertex
      */
     public HugeVertex prepareRemoved() {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertexProperty.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertexProperty.java
index de6c1ee83..4cef51979 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertexProperty.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/structure/HugeVertexProperty.java
@@ -19,19 +19,18 @@ package org.apache.hugegraph.structure;
 
 import java.util.Iterator;
 
+import org.apache.hugegraph.exception.NotSupportException;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.type.HugeType;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Element;
 import org.apache.tinkerpop.gremlin.structure.Property;
 import org.apache.tinkerpop.gremlin.structure.VertexProperty;
 import org.apache.tinkerpop.gremlin.structure.util.ElementHelper;
 
-import org.apache.hugegraph.exception.NotSupportException;
-import org.apache.hugegraph.util.E;
-
 public class HugeVertexProperty<V> extends HugeProperty<V>
-                                   implements VertexProperty<V> {
+        implements VertexProperty<V> {
 
     public HugeVertexProperty(HugeElement owner, PropertyKey key, V value) {
         super(owner, key, value);
@@ -59,7 +58,7 @@ public class HugeVertexProperty<V> extends HugeProperty<V>
         assert this.owner instanceof HugeVertex;
         VertexLabel vertexLabel = ((HugeVertex) this.owner).schemaLabel();
         E.checkArgument(vertexLabel.nullableKeys().contains(
-                        this.propertyKey().id()),
+                                this.propertyKey().id()),
                         "Can't remove non-null vertex property '%s'", this);
         this.owner.graph().removeVertexProperty(this);
     }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/EphemeralJobQueue.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/EphemeralJobQueue.java
index bfb00bff9..c7c840a88 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/EphemeralJobQueue.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/EphemeralJobQueue.java
@@ -185,7 +185,8 @@ public class EphemeralJobQueue {
             return result;
         }
 
-        private Object executeBatchJob(List<EphemeralJob<?>> jobs, Object prevResult) throws Exception {
+        private Object executeBatchJob(List<EphemeralJob<?>> jobs, Object prevResult) throws
+                                                                                      Exception {
             GraphTransaction graphTx = this.params().systemTransaction();
             GraphTransaction systemTx = this.params().graphTransaction();
             Object result = prevResult;
@@ -236,6 +237,7 @@ public class EphemeralJobQueue {
     }
 
     public interface Reduce<T> {
-        T reduce(T t1,  T t2);
+
+        T reduce(T t1, T t2);
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeServerInfo.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeServerInfo.java
index c3fffecce..a304b4f75 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeServerInfo.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeServerInfo.java
@@ -24,6 +24,8 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
 import org.apache.hugegraph.schema.IndexLabel;
@@ -35,21 +37,18 @@ import org.apache.hugegraph.type.define.Cardinality;
 import org.apache.hugegraph.type.define.DataType;
 import org.apache.hugegraph.type.define.NodeRole;
 import org.apache.hugegraph.type.define.SerialEnum;
+import org.apache.hugegraph.util.DateUtil;
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.structure.Graph;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.VertexProperty;
 
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.HugeGraphParams;
-import org.apache.hugegraph.util.DateUtil;
-import org.apache.hugegraph.util.E;
-
 public class HugeServerInfo {
 
     // Unit millisecond
     private static final long EXPIRED_INTERVAL =
-                              TaskManager.SCHEDULE_PERIOD * 10;
+            TaskManager.SCHEDULE_PERIOD * 10;
 
     private Id id;
     private NodeRole role;
@@ -202,7 +201,7 @@ public class HugeServerInfo {
     public static HugeServerInfo fromVertex(Vertex vertex) {
         HugeServerInfo serverInfo = new HugeServerInfo((Id) vertex.id());
         for (Iterator<VertexProperty<Object>> iter = vertex.properties();
-             iter.hasNext();) {
+             iter.hasNext(); ) {
             VertexProperty<Object> prop = iter.next();
             serverInfo.property(prop.key(), prop.value());
         }
@@ -213,11 +212,8 @@ public class HugeServerInfo {
         if (task.computer() != this.role.computer()) {
             return false;
         }
-        if (this.updateTime.getTime() + EXPIRED_INTERVAL < now ||
-            this.load() + task.load() > this.maxLoad) {
-            return false;
-        }
-        return true;
+        return this.updateTime.getTime() + EXPIRED_INTERVAL >= now &&
+               this.load() + task.load() <= this.maxLoad;
     }
 
     public static Schema schema(HugeGraphParams graph) {
@@ -288,7 +284,7 @@ public class HugeServerInfo {
 
         public boolean existVertexLabel(String label) {
             return this.graph.schemaTransaction()
-                       .getVertexLabel(label) != null;
+                             .getVertexLabel(label) != null;
         }
 
         @SuppressWarnings("unused")
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeTask.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeTask.java
index 305c9dc7a..bfd79f6f2 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeTask.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/HugeTask.java
@@ -29,30 +29,31 @@ import java.util.concurrent.FutureTask;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
 
+import org.apache.hugegraph.HugeException;
+import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
+import org.apache.hugegraph.backend.serializer.BytesBuffer;
 import org.apache.hugegraph.config.CoreOptions;
+import org.apache.hugegraph.exception.LimitExceedException;
+import org.apache.hugegraph.exception.NotFoundException;
+import org.apache.hugegraph.job.ComputerJob;
+import org.apache.hugegraph.job.EphemeralJob;
 import org.apache.hugegraph.job.GremlinJob;
 import org.apache.hugegraph.job.schema.SchemaJob;
 import org.apache.hugegraph.type.define.SerialEnum;
-import org.apache.hugegraph.util.*;
+import org.apache.hugegraph.util.Blob;
+import org.apache.hugegraph.util.E;
+import org.apache.hugegraph.util.InsertionOrderUtil;
+import org.apache.hugegraph.util.JsonUtil;
+import org.apache.hugegraph.util.Log;
+import org.apache.hugegraph.util.StringEncoding;
 import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.VertexProperty;
-import org.apache.hugegraph.util.Blob;
-import org.apache.hugegraph.util.JsonUtil;
-import org.apache.hugegraph.util.StringEncoding;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.HugeException;
-import org.apache.hugegraph.HugeGraph;
-import org.apache.hugegraph.backend.serializer.BytesBuffer;
-import org.apache.hugegraph.exception.LimitExceedException;
-import org.apache.hugegraph.exception.NotFoundException;
-import org.apache.hugegraph.job.ComputerJob;
-import org.apache.hugegraph.job.EphemeralJob;
-
 public class HugeTask<V> extends FutureTask<V> {
 
     private static final Logger LOG = Log.logger(HugeTask.class);
@@ -342,9 +343,7 @@ public class HugeTask<V> extends FutureTask<V> {
             LOG.warn("An exception occurred when running task: {}",
                      this.id(), e);
             // Update status to FAILED if exception occurred(not interrupted)
-            if (this.result(TaskStatus.FAILED, e.toString())) {
-                return true;
-            }
+            return this.result(TaskStatus.FAILED, e.toString());
         }
         return false;
     }
@@ -408,14 +407,14 @@ public class HugeTask<V> extends FutureTask<V> {
                 return false;
             } else if (task.status() == TaskStatus.CANCELLED) {
                 this.result(TaskStatus.CANCELLED, String.format(
-                            "Cancelled due to dependent task '%s' cancelled",
-                            dependency));
+                        "Cancelled due to dependent task '%s' cancelled",
+                        dependency));
                 this.done();
                 return false;
             } else if (task.status() == TaskStatus.FAILED) {
                 this.result(TaskStatus.FAILED, String.format(
-                            "Failed due to dependent task '%s' failed",
-                            dependency));
+                        "Failed due to dependent task '%s' failed",
+                        dependency));
                 this.done();
                 return false;
             }
@@ -437,7 +436,7 @@ public class HugeTask<V> extends FutureTask<V> {
         if (!this.completed()) {
             assert this.status.code() < status.code() ||
                    status == TaskStatus.RESTORING :
-                   this.status + " => " + status + " (task " + this.id + ")";
+                    this.status + " => " + status + " (task " + this.id + ")";
             this.status = status;
             return true;
         }
@@ -486,7 +485,7 @@ public class HugeTask<V> extends FutureTask<V> {
                 @SuppressWarnings("unchecked")
                 Set<Long> values = (Set<Long>) value;
                 this.dependencies = values.stream().map(IdGenerator::of)
-                                                   .collect(toOrderSet());
+                                          .collect(toOrderSet());
                 break;
             case P.INPUT:
                 this.input = StringEncoding.decompress(((Blob) value).bytes(),
@@ -555,7 +554,7 @@ public class HugeTask<V> extends FutureTask<V> {
         if (this.dependencies != null) {
             list.add(P.DEPENDENCIES);
             list.add(this.dependencies.stream().map(Id::asLong)
-                                               .collect(toOrderSet()));
+                                      .collect(toOrderSet()));
         }
 
         if (this.input != null) {
@@ -676,7 +675,7 @@ public class HugeTask<V> extends FutureTask<V> {
         }
         if (this.dependencies != null) {
             Set<Long> value = this.dependencies.stream().map(Id::asLong)
-                                                        .collect(toOrderSet());
+                                               .collect(toOrderSet());
             map.put(Hidden.unHide(P.DEPENDENCIES), value);
         }
 
@@ -709,7 +708,7 @@ public class HugeTask<V> extends FutureTask<V> {
 
         HugeTask<V> task = new HugeTask<>((Id) vertex.id(), null, callable);
         for (Iterator<VertexProperty<Object>> iter = vertex.properties();
-             iter.hasNext();) {
+             iter.hasNext(); ) {
             VertexProperty<Object> prop = iter.next();
             task.property(prop.key(), prop.value());
         }
@@ -736,8 +735,8 @@ public class HugeTask<V> extends FutureTask<V> {
 
         if (propertyLength > propertyLimit) {
             throw new LimitExceedException(
-                      "Task %s size %s exceeded limit %s bytes",
-                      P.unhide(propertyName), propertyLength, propertyLimit);
+                    "Task %s size %s exceeded limit %s bytes",
+                    P.unhide(propertyName), propertyLength, propertyLimit);
         }
     }
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/ServerInfoManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/ServerInfoManager.java
index dee899e0f..de0d08b03 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/ServerInfoManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/ServerInfoManager.java
@@ -118,7 +118,7 @@ public class ServerInfoManager {
                 while (servers.hasNext()) {
                     existed = servers.next();
                     E.checkArgument(!existed.role().master() || !existed.alive(),
-                                    "Already existed master '%s' in current cluster", 
+                                    "Already existed master '%s' in current cluster",
                                     existed.id());
                 }
                 if (page != null) {
@@ -324,7 +324,7 @@ public class ServerInfoManager {
 
     private <V> V call(Callable<V> callable) {
         assert !Thread.currentThread().getName().startsWith(
-               "server-info-db-worker") : "can't call by itself";
+                "server-info-db-worker") : "can't call by itself";
         try {
             // Pass context for db thread
             callable = new TaskManager.ContextCallable<>(callable);
@@ -391,7 +391,7 @@ public class ServerInfoManager {
     protected Collection<HugeServerInfo> allServerInfos() {
         Iterator<HugeServerInfo> infos = this.serverInfos(NO_LIMIT, null);
         try (ListIterator<HugeServerInfo> iter = new ListIterator<>(
-                                                 MAX_SERVERS, infos)) {
+                MAX_SERVERS, infos)) {
             return iter.list();
         } catch (Exception e) {
             throw new HugeException("Failed to close server info iterator", e);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/StandardTaskScheduler.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/StandardTaskScheduler.java
index cc08e2a94..8afe11dff 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/StandardTaskScheduler.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/StandardTaskScheduler.java
@@ -38,28 +38,22 @@ import org.apache.hugegraph.backend.query.Condition;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.store.BackendStore;
-import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.config.CoreOptions;
 import org.apache.hugegraph.exception.ConnectionException;
 import org.apache.hugegraph.exception.NotFoundException;
 import org.apache.hugegraph.iterator.ExtendableIterator;
 import org.apache.hugegraph.iterator.MapperIterator;
 import org.apache.hugegraph.job.EphemeralJob;
-import org.apache.hugegraph.schema.IndexLabel;
 import org.apache.hugegraph.schema.PropertyKey;
-import org.apache.hugegraph.schema.SchemaManager;
 import org.apache.hugegraph.schema.VertexLabel;
 import org.apache.hugegraph.structure.HugeVertex;
 import org.apache.hugegraph.task.HugeTask.P;
 import org.apache.hugegraph.task.TaskCallable.SysTaskCallable;
 import org.apache.hugegraph.task.TaskManager.ContextCallable;
 import org.apache.hugegraph.type.HugeType;
-import org.apache.hugegraph.type.define.Cardinality;
-import org.apache.hugegraph.type.define.DataType;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
-import org.apache.tinkerpop.gremlin.structure.Graph.Hidden;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.slf4j.Logger;
 
@@ -145,7 +139,7 @@ public class StandardTaskScheduler implements TaskScheduler {
             do {
                 Iterator<HugeTask<V>> iter;
                 for (iter = this.findTask(status, PAGE_SIZE, page);
-                     iter.hasNext();) {
+                     iter.hasNext(); ) {
                     HugeTask<V> task = iter.next();
                     if (selfServer.equals(task.server())) {
                         taskList.add(task);
@@ -156,7 +150,7 @@ public class StandardTaskScheduler implements TaskScheduler {
                 }
             } while (page != null);
         }
-        for (HugeTask<V> task : taskList){
+        for (HugeTask<V> task : taskList) {
             LOG.info("restore task {}", task);
             this.restore(task);
         }
@@ -325,7 +319,7 @@ public class StandardTaskScheduler implements TaskScheduler {
                 }
 
                 HugeServerInfo server = this.serverManager().pickWorkerNode(
-                                        serverInfos, task);
+                        serverInfos, task);
                 if (server == null) {
                     LOG.info("The master can't find suitable servers to " +
                              "execute task '{}', wait for next schedule",
@@ -445,7 +439,7 @@ public class StandardTaskScheduler implements TaskScheduler {
         HugeTask<?> delTask = this.tasks.remove(task.id());
         if (delTask != null && delTask != task) {
             LOG.warn("Task '{}' may be inconsistent status {}(expect {})",
-                      task.id(), task.status(), delTask.status());
+                     task.id(), task.status(), delTask.status());
         }
         assert force || delTask == null || delTask.completed() ||
                delTask.cancelling() || delTask.isCancelled() : delTask;
@@ -597,13 +591,13 @@ public class StandardTaskScheduler implements TaskScheduler {
 
     @Override
     public <V> HugeTask<V> waitUntilTaskCompleted(Id id, long seconds)
-                                                  throws TimeoutException {
+            throws TimeoutException {
         return this.waitUntilTaskCompleted(id, seconds, QUERY_INTERVAL);
     }
 
     @Override
     public <V> HugeTask<V> waitUntilTaskCompleted(Id id)
-                                                  throws TimeoutException {
+            throws TimeoutException {
         // This method is just used by tests
         long timeout = this.graph.configuration()
                                  .get(CoreOptions.TASK_WAIT_TIMEOUT);
@@ -612,10 +606,10 @@ public class StandardTaskScheduler implements TaskScheduler {
 
     private <V> HugeTask<V> waitUntilTaskCompleted(Id id, long seconds,
                                                    long intervalMs)
-                                                   throws TimeoutException {
+            throws TimeoutException {
         long passes = seconds * 1000 / intervalMs;
         HugeTask<V> task = null;
-        for (long pass = 0;; pass++) {
+        for (long pass = 0; ; pass++) {
             try {
                 task = this.task(id);
             } catch (NotFoundException e) {
@@ -637,15 +631,15 @@ public class StandardTaskScheduler implements TaskScheduler {
             sleep(intervalMs);
         }
         throw new TimeoutException(String.format(
-                  "Task '%s' was not completed in %s seconds", id, seconds));
+                "Task '%s' was not completed in %s seconds", id, seconds));
     }
 
     @Override
     public void waitUntilAllTasksCompleted(long seconds)
-                                           throws TimeoutException {
+            throws TimeoutException {
         long passes = seconds * 1000 / QUERY_INTERVAL;
         int taskSize;
-        for (long pass = 0;; pass++) {
+        for (long pass = 0; ; pass++) {
             taskSize = this.pendingTasks();
             if (taskSize == 0) {
                 sleep(QUERY_INTERVAL);
@@ -657,8 +651,8 @@ public class StandardTaskScheduler implements TaskScheduler {
             sleep(QUERY_INTERVAL);
         }
         throw new TimeoutException(String.format(
-                  "There are still %s incomplete tasks after %s seconds",
-                  taskSize, seconds));
+                "There are still %s incomplete tasks after %s seconds",
+                taskSize, seconds));
     }
 
     @Override
@@ -718,9 +712,9 @@ public class StandardTaskScheduler implements TaskScheduler {
     }
 
     @Override
-    public  <V> V call(Callable<V> callable) {
+    public <V> V call(Callable<V> callable) {
         assert !Thread.currentThread().getName().startsWith(
-               "task-db-worker") : "can't call by itself";
+                "task-db-worker") : "can't call by itself";
         try {
             // Pass task context for db thread
             callable = new ContextCallable<>(callable);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskCallable.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskCallable.java
index b19fb796d..ec066fbc0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskCallable.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskCallable.java
@@ -21,14 +21,14 @@ import java.util.Date;
 import java.util.Set;
 import java.util.concurrent.Callable;
 
-import org.apache.tinkerpop.gremlin.structure.Transaction;
-import org.slf4j.Logger;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.HugeGraphParams;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.Log;
+import org.apache.tinkerpop.gremlin.structure.Transaction;
+import org.slf4j.Logger;
+
 import com.google.common.collect.ImmutableSet;
 
 public abstract class TaskCallable<V> implements Callable<V> {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskManager.java
index 14e91d301..144387949 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskManager.java
@@ -45,7 +45,7 @@ public final class TaskManager {
     public static final String TASK_WORKER = TASK_WORKER_PREFIX + "-%d";
     public static final String TASK_DB_WORKER = "task-db-worker-%d";
     public static final String SERVER_INFO_DB_WORKER =
-                               "server-info-db-worker-%d";
+            "server-info-db-worker-%d";
     public static final String TASK_SCHEDULER = "task-scheduler-%d";
 
     protected static final long SCHEDULE_PERIOD = 1000L; // unit ms
@@ -73,12 +73,12 @@ public final class TaskManager {
         this.taskExecutor = ExecutorUtil.newFixedThreadPool(pool, TASK_WORKER);
         // For save/query task state, just one thread is ok
         this.taskDbExecutor = ExecutorUtil.newFixedThreadPool(
-                              1, TASK_DB_WORKER);
+                1, TASK_DB_WORKER);
         this.serverInfoDbExecutor = ExecutorUtil.newFixedThreadPool(
-                                    1, SERVER_INFO_DB_WORKER);
+                1, SERVER_INFO_DB_WORKER);
         // For schedule task to run, just one thread is ok
         this.schedulerExecutor = ExecutorUtil.newPausableScheduledThreadPool(
-                                 1, TASK_SCHEDULER);
+                1, TASK_SCHEDULER);
         // Start after 10x period time waiting for HugeGraphServer startup
         this.schedulerExecutor.scheduleWithFixedDelay(this::scheduleOrExecuteJob,
                                                       10 * SCHEDULE_PERIOD,
@@ -90,8 +90,8 @@ public final class TaskManager {
         E.checkArgumentNotNull(graph, "The graph can't be null");
 
         TaskScheduler scheduler = new StandardTaskScheduler(graph,
-                                  this.taskExecutor, this.taskDbExecutor,
-                                  this.serverInfoDbExecutor);
+                                                            this.taskExecutor, this.taskDbExecutor,
+                                                            this.serverInfoDbExecutor);
         this.schedulers.put(graph, scheduler);
     }
 
@@ -171,7 +171,7 @@ public final class TaskManager {
 
     public ServerInfoManager getServerInfoManager(HugeGraphParams graph) {
         StandardTaskScheduler scheduler = (StandardTaskScheduler)
-                                          this.getScheduler(graph);
+                this.getScheduler(graph);
         if (scheduler == null) {
             return null;
         }
@@ -275,7 +275,7 @@ public final class TaskManager {
 
     protected void notifyNewTask(HugeTask<?> task) {
         Queue<Runnable> queue = ((ThreadPoolExecutor) this.schedulerExecutor)
-                                                          .getQueue();
+                .getQueue();
         if (queue.size() <= 1) {
             /*
              * Notify to schedule tasks initiatively when have new task
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskScheduler.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskScheduler.java
index 4a6993b5e..b72ee91a8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskScheduler.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskScheduler.java
@@ -23,8 +23,8 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeoutException;
 
-import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.HugeGraph;
+import org.apache.hugegraph.backend.id.Id;
 
 public interface TaskScheduler {
 
@@ -59,13 +59,13 @@ public interface TaskScheduler {
     boolean close();
 
     <V> HugeTask<V> waitUntilTaskCompleted(Id id, long seconds)
-                                           throws TimeoutException;
+            throws TimeoutException;
 
     <V> HugeTask<V> waitUntilTaskCompleted(Id id)
-                                           throws TimeoutException;
+            throws TimeoutException;
 
     void waitUntilAllTasksCompleted(long seconds)
-                                    throws TimeoutException;
+            throws TimeoutException;
 
     void checkRequirement(String op);
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskStatus.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskStatus.java
index db89da6f1..d87a20c0a 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskStatus.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/task/TaskStatus.java
@@ -21,6 +21,7 @@ import java.util.List;
 import java.util.Set;
 
 import org.apache.hugegraph.type.define.SerialEnum;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 
@@ -43,10 +44,10 @@ public enum TaskStatus implements SerialEnum {
 
     // NOTE: order is important(RESTORING > RUNNING > QUEUED) when restoring
     public static final List<TaskStatus> PENDING_STATUSES = ImmutableList.of(
-           TaskStatus.RESTORING, TaskStatus.RUNNING, TaskStatus.QUEUED);
+            TaskStatus.RESTORING, TaskStatus.RUNNING, TaskStatus.QUEUED);
 
     public static final Set<TaskStatus> COMPLETED_STATUSES = ImmutableSet.of(
-           TaskStatus.SUCCESS, TaskStatus.CANCELLED, TaskStatus.FAILED);
+            TaskStatus.SUCCESS, TaskStatus.CANCELLED, TaskStatus.FAILED);
 
     private byte status;
     private String name;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/CountTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/CountTraverser.java
index 3ef81e538..1b9defac4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/CountTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/CountTraverser.java
@@ -25,13 +25,12 @@ import org.apache.commons.lang.mutable.MutableLong;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.query.QueryResults;
-import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-
 import org.apache.hugegraph.iterator.FilterIterator;
 import org.apache.hugegraph.iterator.FlatMapperIterator;
 import org.apache.hugegraph.structure.HugeEdge;
+import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.Edge;
 import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
 public class CountTraverser extends HugeTraverser {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/HugeTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/HugeTraverser.java
index 53ced03c6..e75d01635 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/HugeTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/HugeTraverser.java
@@ -947,6 +947,7 @@ public class HugeTraverser {
     }
 
     public static class EdgeRecord {
+
         private final Map<Long, Edge> edgeMap;
         private final ObjectIntMapping<Id> idMapping;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/NeighborRankTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/NeighborRankTraverser.java
index e5f99b403..3e915c7dd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/NeighborRankTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/NeighborRankTraverser.java
@@ -22,17 +22,16 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import jakarta.ws.rs.core.MultivaluedMap;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
+import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.type.define.Directions;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-
-import org.apache.hugegraph.structure.HugeEdge;
 import org.apache.hugegraph.util.E;
 import org.apache.hugegraph.util.OrderLimitMap;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+
+import jakarta.ws.rs.core.MultivaluedMap;
 
 public class NeighborRankTraverser extends HugeTraverser {
 
@@ -162,7 +161,7 @@ public class NeighborRankTraverser extends HugeTraverser {
             Ranks prevLayerRanks = ranks.get(i);
             if (prevLayerRanks.containsKey(target)) {
                 Set<Id> nodes = prevLayerNodes.computeIfAbsent(
-                                i, HugeTraverser::newSet);
+                        i, HugeTraverser::newSet);
                 nodes.add(target);
                 return true;
             }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/OltpTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/OltpTraverser.java
index 40fe914d4..44f9cf869 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/OltpTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/OltpTraverser.java
@@ -49,7 +49,7 @@ import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 import com.google.common.base.Objects;
 
 public abstract class OltpTraverser extends HugeTraverser
-                                    implements AutoCloseable {
+        implements AutoCloseable {
 
     private static final String EXECUTOR_NAME = "oltp";
     private static Consumers.ExecutorPool executors;
@@ -149,7 +149,7 @@ public abstract class OltpTraverser extends HugeTraverser
                                     long capacity,
                                     Consumer<EdgeId> consumer) {
         List<Id> labels = label == null ? Collections.emptyList() :
-                                          Collections.singletonList(label);
+                          Collections.singletonList(label);
         OneStepEdgeIterConsumer edgeIterConsumer = new OneStepEdgeIterConsumer(consumer, capacity);
 
         EdgesIterator edgeIter = edgesOfVertices(vertices, dir, labels, degree);
@@ -248,7 +248,7 @@ public abstract class OltpTraverser extends HugeTraverser
     }
 
     public static class ConcurrentMultiValuedMap<K, V>
-                  extends ConcurrentHashMap<K, List<V>> {
+            extends ConcurrentHashMap<K, List<V>> {
 
         private static final long serialVersionUID = -7249946839643493614L;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PersonalRankTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PersonalRankTraverser.java
index 1a1e82cad..972eff7c7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PersonalRankTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PersonalRankTraverser.java
@@ -27,11 +27,10 @@ import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.EdgeLabel;
 import org.apache.hugegraph.schema.VertexLabel;
-import org.apache.hugegraph.type.define.Directions;
-import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
-
 import org.apache.hugegraph.structure.HugeVertex;
+import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
 
 public class PersonalRankTraverser extends HugeTraverser {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PredictionTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PredictionTraverser.java
index 4a3df4d64..4b2cb69e5 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PredictionTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/PredictionTraverser.java
@@ -24,6 +24,7 @@ import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.collect.ImmutableList;
 
 public class PredictionTraverser extends OltpTraverser {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/ShortestPathTraverser.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/ShortestPathTraverser.java
index 4e9b88ec1..a34f87289 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/ShortestPathTraverser.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/ShortestPathTraverser.java
@@ -198,8 +198,9 @@ public class ShortestPathTraverser extends HugeTraverser {
                     this.edgeResults.addEdge(source, target, edge);
 
                     PathSet paths = this.pathResults.findPath(target,
-                                                         t -> !this.superNode(t, this.direction),
-                                                         all, false);
+                                                              t -> !this.superNode(t,
+                                                                                   this.direction),
+                                                              all, false);
 
                     if (paths.isEmpty()) {
                         continue;
@@ -244,8 +245,8 @@ public class ShortestPathTraverser extends HugeTraverser {
                     this.edgeResults.addEdge(source, target, edge);
 
                     PathSet paths = this.pathResults.findPath(target,
-                                                         t -> !this.superNode(t, opposite),
-                                                         all, false);
+                                                              t -> !this.superNode(t, opposite),
+                                                              all, false);
 
                     if (paths.isEmpty()) {
                         continue;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/AbstractRecords.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/AbstractRecords.java
index 7b94454cb..74f3db5ff 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/AbstractRecords.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/AbstractRecords.java
@@ -19,12 +19,12 @@ package org.apache.hugegraph.traversal.algorithm.records;
 
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.backend.id.IdGenerator;
-import org.apache.hugegraph.util.collection.ObjectIntMapping;
-import org.apache.hugegraph.util.collection.ObjectIntMappingFactory;
 import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.traversal.algorithm.records.record.Record;
 import org.apache.hugegraph.traversal.algorithm.records.record.RecordFactory;
 import org.apache.hugegraph.traversal.algorithm.records.record.RecordType;
+import org.apache.hugegraph.util.collection.ObjectIntMapping;
+import org.apache.hugegraph.util.collection.ObjectIntMappingFactory;
 
 public abstract class AbstractRecords implements Records {
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/DoubleWayMultiPathsRecords.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/DoubleWayMultiPathsRecords.java
index 4600f0790..33224dc92 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/DoubleWayMultiPathsRecords.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/DoubleWayMultiPathsRecords.java
@@ -22,14 +22,14 @@ import java.util.List;
 import java.util.Stack;
 
 import org.apache.commons.collections.CollectionUtils;
-
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.util.collection.IntIterator;
 import org.apache.hugegraph.perf.PerfUtil.Watched;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser.Path;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser.PathSet;
 import org.apache.hugegraph.traversal.algorithm.records.record.Record;
 import org.apache.hugegraph.traversal.algorithm.records.record.RecordType;
+import org.apache.hugegraph.util.collection.IntIterator;
+
 import com.google.common.collect.Lists;
 
 public abstract class DoubleWayMultiPathsRecords extends AbstractRecords {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/KoutRecords.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/KoutRecords.java
index f13bcbce6..bd637ce1d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/KoutRecords.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/KoutRecords.java
@@ -97,7 +97,7 @@ public class KoutRecords extends SingleWayMultiPathsRecords {
             if (this.sourceCode == targetCode) {
                 break;
             }
-            
+
             this.addPathToRecord(sourceCode, targetCode, record);
             sourceCode = targetCode;
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/record/SyncRecord.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/record/SyncRecord.java
index 4a113fb4e..c743ed5a4 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/record/SyncRecord.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/records/record/SyncRecord.java
@@ -31,7 +31,7 @@ public class SyncRecord implements Record {
     public SyncRecord(Record record, Object newLock) {
         if (record == null) {
             throw new IllegalArgumentException(
-                      "Cannot create a SyncRecord on a null record");
+                    "Cannot create a SyncRecord on a null record");
         } else {
             this.record = record;
             this.lock = newLock == null ? this : newLock;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/EdgeStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/EdgeStep.java
index 06cfd6606..caff267b7 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/EdgeStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/EdgeStep.java
@@ -28,12 +28,12 @@ import java.util.Map;
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
 import org.apache.hugegraph.schema.EdgeLabel;
-import org.apache.hugegraph.type.define.Directions;
-import org.apache.tinkerpop.gremlin.structure.Edge;
-
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.traversal.optimize.TraversalUtil;
+import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/RepeatEdgeStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/RepeatEdgeStep.java
index 29a3572c1..1ab5fb1e0 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/RepeatEdgeStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/RepeatEdgeStep.java
@@ -24,6 +24,7 @@ import java.util.Map;
 
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.type.define.Directions;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/WeightedEdgeStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/WeightedEdgeStep.java
index 81b3cffd3..b288420ff 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/WeightedEdgeStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/steps/WeightedEdgeStep.java
@@ -28,6 +28,7 @@ import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.schema.PropertyKey;
 import org.apache.hugegraph.type.define.Directions;
 import org.apache.hugegraph.util.E;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/ConcurrentTraverseStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/ConcurrentTraverseStrategy.java
index 2110df8f8..235a3c2d9 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/ConcurrentTraverseStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/ConcurrentTraverseStrategy.java
@@ -29,7 +29,7 @@ import org.apache.hugegraph.traversal.algorithm.OltpTraverser;
 import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 
 public class ConcurrentTraverseStrategy extends OltpTraverser
-                                        implements TraverseStrategy {
+        implements TraverseStrategy {
 
     public ConcurrentTraverseStrategy(HugeGraph graph) {
         super(graph);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/SingleTraverseStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/SingleTraverseStrategy.java
index a3bb7ada5..8516645cd 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/SingleTraverseStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/SingleTraverseStrategy.java
@@ -22,16 +22,16 @@ import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
 
-import jakarta.ws.rs.core.MultivaluedMap;
-
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
 import org.apache.hugegraph.traversal.algorithm.OltpTraverser;
+import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
+
+import jakarta.ws.rs.core.MultivaluedMap;
 
 public class SingleTraverseStrategy extends OltpTraverser
-                                    implements TraverseStrategy {
+        implements TraverseStrategy {
 
     public SingleTraverseStrategy(HugeGraph graph) {
         super(graph);
@@ -65,7 +65,7 @@ public class SingleTraverseStrategy extends OltpTraverser
     public void addNewVerticesToAll(Map<Id, List<Node>> newVertices,
                                     Map<Id, List<Node>> targets) {
         MultivaluedMap<Id, Node> vertices =
-                                 (MultivaluedMap<Id, Node>) targets;
+                (MultivaluedMap<Id, Node>) targets;
         for (Map.Entry<Id, List<Node>> entry : newVertices.entrySet()) {
             vertices.addAll(entry.getKey(), entry.getValue());
         }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/TraverseStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/TraverseStrategy.java
index e3c21cfa6..744013303 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/TraverseStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/algorithm/strategy/TraverseStrategy.java
@@ -24,8 +24,8 @@ import java.util.function.BiConsumer;
 
 import org.apache.hugegraph.HugeGraph;
 import org.apache.hugegraph.backend.id.Id;
-import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 import org.apache.hugegraph.traversal.algorithm.HugeTraverser;
+import org.apache.hugegraph.traversal.algorithm.steps.EdgeStep;
 
 public interface TraverseStrategy {
 
@@ -44,6 +44,6 @@ public interface TraverseStrategy {
 
     static TraverseStrategy create(boolean concurrent, HugeGraph graph) {
         return concurrent ? new ConcurrentTraverseStrategy(graph) :
-                            new SingleTraverseStrategy(graph);
+               new SingleTraverseStrategy(graph);
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStep.java
index 8bf2e8464..403bf5be8 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStep.java
@@ -20,6 +20,7 @@ package org.apache.hugegraph.traversal.optimize;
 import java.util.NoSuchElementException;
 import java.util.Objects;
 
+import org.apache.hugegraph.util.E;
 import org.apache.tinkerpop.gremlin.process.traversal.Step;
 import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
 import org.apache.tinkerpop.gremlin.process.traversal.Traverser.Admin;
@@ -27,10 +28,8 @@ import org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep;
 import org.apache.tinkerpop.gremlin.process.traversal.util.FastNoSuchElementException;
 import org.apache.tinkerpop.gremlin.structure.Element;
 
-import org.apache.hugegraph.util.E;
-
 public final class HugeCountStep<S extends Element>
-             extends AbstractStep<S, Long> {
+        extends AbstractStep<S, Long> {
 
     private static final long serialVersionUID = -679873894532085972L;
 
@@ -44,6 +43,7 @@ public final class HugeCountStep<S extends Element>
         this.originGraphStep = originGraphStep;
     }
 
+    @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof HugeCountStep)) {
             return false;
@@ -69,7 +69,7 @@ public final class HugeCountStep<S extends Element>
             throw FastNoSuchElementException.instance();
         }
         this.done = true;
-        @SuppressWarnings({ "unchecked", "rawtypes" })
+        @SuppressWarnings({"unchecked", "rawtypes"})
         Step<Long, Long> step = (Step) this;
         return this.getTraversal().getTraverserGenerator()
                    .generate(this.originGraphStep.count(), step, 1L);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStepStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStepStrategy.java
index 4bb3a33c8..ef380d36b 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStepStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeCountStepStrategy.java
@@ -40,8 +40,8 @@ import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper;
 import org.apache.tinkerpop.gremlin.structure.Element;
 
 public final class HugeCountStepStrategy
-             extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
-             implements ProviderOptimizationStrategy {
+        extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
+        implements ProviderOptimizationStrategy {
 
     private static final long serialVersionUID = -3910433925919057771L;
 
@@ -56,13 +56,13 @@ public final class HugeCountStepStrategy
     }
 
     @Override
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public void apply(Traversal.Admin<?, ?> traversal) {
         TraversalUtil.convAllHasSteps(traversal);
 
         // Extract CountGlobalStep
         List<CountGlobalStep> steps = TraversalHelper.getStepsOfClass(
-                                      CountGlobalStep.class, traversal);
+                CountGlobalStep.class, traversal);
         if (steps.isEmpty()) {
             return;
         }
@@ -78,12 +78,12 @@ public final class HugeCountStepStrategy
                   step instanceof IdentityStep ||
                   step instanceof NoOpBarrierStep ||
                   step instanceof CollectingBarrierStep) ||
-                 (step instanceof TraversalParent &&
-                  TraversalHelper.anyStepRecursively(s -> {
-                      return s instanceof SideEffectStep ||
-                             s instanceof AggregateGlobalStep ||
-                             s instanceof AggregateLocalStep;
-                  }, (TraversalParent) step))) {
+                (step instanceof TraversalParent &&
+                 TraversalHelper.anyStepRecursively(s -> {
+                     return s instanceof SideEffectStep ||
+                            s instanceof AggregateGlobalStep ||
+                            s instanceof AggregateLocalStep;
+                 }, (TraversalParent) step))) {
                 return;
             }
             originSteps.add(step);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStep.java
index 21e624e86..bdfb9e0b6 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStep.java
@@ -28,6 +28,7 @@ import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.type.HugeType;
+import org.apache.hugegraph.util.Log;
 import org.apache.tinkerpop.gremlin.process.traversal.step.map.GraphStep;
 import org.apache.tinkerpop.gremlin.process.traversal.step.util.HasContainer;
 import org.apache.tinkerpop.gremlin.structure.Element;
@@ -35,10 +36,8 @@ import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
 import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.util.Log;
-
 public final class HugeGraphStep<S, E extends Element>
-             extends GraphStep<S, E> implements QueryHolder {
+        extends GraphStep<S, E> implements QueryHolder {
 
     private static final long serialVersionUID = -679873894532085972L;
 
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStepStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStepStrategy.java
index af1511e15..cc3ef3f5f 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStepStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeGraphStepStrategy.java
@@ -28,8 +28,8 @@ import org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversal
 import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper;
 
 public final class HugeGraphStepStrategy
-             extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
-             implements ProviderOptimizationStrategy {
+        extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
+        implements ProviderOptimizationStrategy {
 
     private static final long serialVersionUID = -2952498905649139719L;
 
@@ -44,13 +44,13 @@ public final class HugeGraphStepStrategy
     }
 
     @Override
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public void apply(Traversal.Admin<?, ?> traversal) {
         TraversalUtil.convAllHasSteps(traversal);
 
         // Extract conditions in GraphStep
         List<GraphStep> steps = TraversalHelper.getStepsOfClass(
-                                GraphStep.class, traversal);
+                GraphStep.class, traversal);
         for (GraphStep originStep : steps) {
             TraversalUtil.trySetGraph(originStep,
                                       TraversalUtil.tryGetGraph(steps.get(0)));
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugePrimaryKeyStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugePrimaryKeyStrategy.java
index 95dc187b5..e6fa88083 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugePrimaryKeyStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugePrimaryKeyStrategy.java
@@ -33,8 +33,8 @@ import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.VertexProperty.Cardinality;
 
 public class HugePrimaryKeyStrategy
-    extends AbstractTraversalStrategy<TraversalStrategy.ProviderOptimizationStrategy>
-    implements ProviderOptimizationStrategy {
+        extends AbstractTraversalStrategy<TraversalStrategy.ProviderOptimizationStrategy>
+        implements ProviderOptimizationStrategy {
 
     private static final long serialVersionUID = 6307847098226016416L;
     private static final HugePrimaryKeyStrategy INSTANCE = new HugePrimaryKeyStrategy();
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeScriptTraversal.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeScriptTraversal.java
index 66d40e9b2..0ccb48a54 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeScriptTraversal.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeScriptTraversal.java
@@ -36,7 +36,7 @@ import org.apache.tinkerpop.gremlin.process.traversal.util.DefaultTraversal;
 /**
  * ScriptTraversal encapsulates a {@link ScriptEngine} and a script which is
  * compiled into a {@link Traversal} at {@link Admin#applyStrategies()}.
- *
+ * <p>
  * This is useful for serializing traversals as the compilation can happen on
  * the remote end where the traversal will ultimately be processed.
  *
@@ -101,7 +101,7 @@ public final class HugeScriptTraversal<S, E> extends DefaultTraversal<S, E> {
             Object result = engine.eval(this.script, bindings);
 
             if (result instanceof Admin) {
-                @SuppressWarnings({ "unchecked"})
+                @SuppressWarnings({"unchecked"})
                 Admin<S, E> traversal = (Admin<S, E>) result;
                 traversal.getSideEffects().mergeInto(this.sideEffects);
                 traversal.getSteps().forEach(this::addStep);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStep.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStep.java
index 1132bc83f..1a3fc58be 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStep.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStep.java
@@ -30,6 +30,7 @@ import org.apache.hugegraph.backend.query.Query;
 import org.apache.hugegraph.backend.query.QueryResults;
 import org.apache.hugegraph.backend.tx.GraphTransaction;
 import org.apache.hugegraph.type.define.Directions;
+import org.apache.hugegraph.util.Log;
 import org.apache.tinkerpop.gremlin.process.traversal.Traverser;
 import org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStep;
 import org.apache.tinkerpop.gremlin.process.traversal.step.util.HasContainer;
@@ -39,10 +40,8 @@ import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
 import org.slf4j.Logger;
 
-import org.apache.hugegraph.util.Log;
-
 public class HugeVertexStep<E extends Element>
-       extends VertexStep<E> implements QueryHolder {
+        extends VertexStep<E> implements QueryHolder {
 
     private static final long serialVersionUID = -7850636388424382454L;
 
@@ -124,7 +123,7 @@ public class HugeVertexStep<E extends Element>
     }
 
     protected ConditionQuery constructEdgesQuery(
-                             Traverser.Admin<Vertex> traverser) {
+            Traverser.Admin<Vertex> traverser) {
         HugeGraph graph = TraversalUtil.getGraph(this);
 
         // Query for edge with conditions(else conditions for vertex)
@@ -140,7 +139,7 @@ public class HugeVertexStep<E extends Element>
                   vertex, direction, edgeLabels, this.hasContainers);
 
         ConditionQuery query = GraphTransaction.constructEdgesQuery(
-                               vertex, direction, edgeLabels);
+                vertex, direction, edgeLabels);
         // Query by sort-keys
         if (withEdgeCond && edgeLabels.length == 1) {
             TraversalUtil.fillConditionQuery(query, this.hasContainers, graph);
@@ -173,8 +172,8 @@ public class HugeVertexStep<E extends Element>
          */
         if (withEdgeCond || withVertexCond) {
             org.apache.hugegraph.util.E.checkArgument(!this.queryInfo().paging(),
-                                                     "Can't query by paging " +
-                                                     "and filtering");
+                                                      "Can't query by paging " +
+                                                      "and filtering");
             this.queryInfo().limit(Query.NO_LIMIT);
         }
 
@@ -198,11 +197,11 @@ public class HugeVertexStep<E extends Element>
         }
 
         return StringFactory.stepString(
-               this,
-               getDirection(),
-               Arrays.asList(getEdgeLabels()),
-               getReturnClass().getSimpleName(),
-               this.hasContainers);
+                this,
+                getDirection(),
+                Arrays.asList(getEdgeLabels()),
+                getReturnClass().getSimpleName(),
+                this.hasContainers);
     }
 
     @Override
@@ -229,6 +228,7 @@ public class HugeVertexStep<E extends Element>
         return this.iterator;
     }
 
+    @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof HugeVertexStep)) {
             return false;
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepByBatch.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepByBatch.java
index a1bc02ca0..951784733 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepByBatch.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepByBatch.java
@@ -23,6 +23,7 @@ import java.util.List;
 import org.apache.hugegraph.backend.query.BatchConditionQuery;
 import org.apache.hugegraph.backend.query.ConditionQuery;
 import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.iterator.BatchMapperIterator;
 import org.apache.hugegraph.type.HugeType;
 import org.apache.hugegraph.type.define.HugeKeys;
 import org.apache.tinkerpop.gremlin.process.traversal.Traverser;
@@ -33,10 +34,8 @@ import org.apache.tinkerpop.gremlin.structure.Element;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.util.CloseableIterator;
 
-import org.apache.hugegraph.iterator.BatchMapperIterator;
-
 public class HugeVertexStepByBatch<E extends Element>
-       extends HugeVertexStep<E> {
+        extends HugeVertexStep<E> {
 
     private static final long serialVersionUID = -3609787815053052222L;
 
@@ -57,7 +56,7 @@ public class HugeVertexStepByBatch<E extends Element>
         if (this.batchIterator == null) {
             int batchSize = (int) Query.QUERY_BATCH;
             this.batchIterator = new BatchMapperIterator<>(
-                                 batchSize, this.starts, this::flatMap);
+                    batchSize, this.starts, this::flatMap);
         }
 
         if (this.batchIterator.hasNext()) {
@@ -110,7 +109,7 @@ public class HugeVertexStepByBatch<E extends Element>
     }
 
     private Iterator<Vertex> vertices(
-                             List<Traverser.Admin<Vertex>> traversers) {
+            List<Traverser.Admin<Vertex>> traversers) {
         assert traversers.size() > 0;
 
         Iterator<Edge> edges = this.edges(traversers);
@@ -121,7 +120,7 @@ public class HugeVertexStepByBatch<E extends Element>
         assert traversers.size() > 0;
 
         BatchConditionQuery batchQuery = new BatchConditionQuery(
-                                         HugeType.EDGE, traversers.size());
+                HugeType.EDGE, traversers.size());
 
         for (Traverser.Admin<Vertex> traverser : traversers) {
             ConditionQuery query = this.constructEdgesQuery(traverser);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepStrategy.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepStrategy.java
index a01b1ed23..a7dd68734 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepStrategy.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeVertexStepStrategy.java
@@ -31,8 +31,8 @@ import org.apache.tinkerpop.gremlin.process.traversal.util.EmptyTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper;
 
 public final class HugeVertexStepStrategy
-             extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
-             implements ProviderOptimizationStrategy {
+        extends AbstractTraversalStrategy<ProviderOptimizationStrategy>
+        implements ProviderOptimizationStrategy {
 
     private static final long serialVersionUID = 491355700217483162L;
 
@@ -47,12 +47,12 @@ public final class HugeVertexStepStrategy
     }
 
     @Override
-    @SuppressWarnings({ "rawtypes", "unchecked" })
+    @SuppressWarnings({"rawtypes", "unchecked"})
     public void apply(final Traversal.Admin<?, ?> traversal) {
         TraversalUtil.convAllHasSteps(traversal);
 
         List<VertexStep> steps = TraversalHelper.getStepsOfClass(
-                                 VertexStep.class, traversal);
+                VertexStep.class, traversal);
 
         boolean batchOptimize = false;
         if (!steps.isEmpty()) {
@@ -92,12 +92,13 @@ public final class HugeVertexStepStrategy
 
     /**
      * Does a Traversal contain any Path step
+     *
      * @param traversal
      * @return the traversal or its parents contain at least one Path step
      */
     protected static boolean containsPath(Traversal.Admin<?, ?> traversal) {
         boolean hasPath = TraversalHelper.getStepsOfClass(
-                          PathStep.class, traversal).size() > 0;
+                PathStep.class, traversal).size() > 0;
         if (hasPath) {
             return true;
         } else if (traversal instanceof EmptyTraversal) {
@@ -110,12 +111,13 @@ public final class HugeVertexStepStrategy
 
     /**
      * Does a Traversal contain any Tree step
+     *
      * @param traversal
      * @return the traversal or its parents contain at least one Tree step
      */
     protected static boolean containsTree(Traversal.Admin<?, ?> traversal) {
         boolean hasTree = TraversalHelper.getStepsOfClass(
-                          TreeStep.class, traversal).size() > 0;
+                TreeStep.class, traversal).size() > 0;
         if (hasTree) {
             return true;
         } else if (traversal instanceof EmptyTraversal) {
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/QueryHolder.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/QueryHolder.java
index 322744ac2..917f777b9 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/QueryHolder.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/QueryHolder.java
@@ -21,11 +21,10 @@ import java.util.Iterator;
 
 import org.apache.hugegraph.backend.query.Aggregate;
 import org.apache.hugegraph.backend.query.Query;
+import org.apache.hugegraph.iterator.Metadatable;
 import org.apache.tinkerpop.gremlin.process.traversal.Order;
 import org.apache.tinkerpop.gremlin.process.traversal.step.HasContainerHolder;
 
-import org.apache.hugegraph.iterator.Metadatable;
-
 public interface QueryHolder extends HasContainerHolder, Metadatable {
 
     String SYSPROP_PAGE = "~page";
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/TraversalUtil.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/TraversalUtil.java
index 204c47807..11a5c0cee 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/TraversalUtil.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/TraversalUtil.java
@@ -243,7 +243,7 @@ public final class TraversalUtil {
                     long limit = holder.setRange(range.getLowRange(),
                                                  range.getHighRange());
                     RangeGlobalStep<Object> newRange = new RangeGlobalStep<>(
-                                                       traversal, 0, limit);
+                            traversal, 0, limit);
                     TraversalHelper.replaceStep(range, newRange, traversal);
                 }
             }
@@ -311,9 +311,9 @@ public final class TraversalUtil {
     }
 
     public static ConditionQuery fillConditionQuery(
-                                 ConditionQuery query,
-                                 List<HasContainer> hasContainers,
-                                 HugeGraph graph) {
+            ConditionQuery query,
+            List<HasContainer> hasContainers,
+            HugeGraph graph) {
         HugeType resultType = query.resultType();
 
         for (HasContainer has : hasContainers) {
@@ -550,7 +550,7 @@ public final class TraversalUtil {
         // Convert contains-key or contains-value
         BiPredicate<?, ?> bp = has.getPredicate().getBiPredicate();
         E.checkArgument(bp == Compare.eq, "CONTAINS query with relation " +
-                        "'%s' is not supported", bp);
+                                          "'%s' is not supported", bp);
 
         HugeKeys key = token2HugeKey(has.getKey());
         E.checkNotNull(key, "token key");
@@ -602,8 +602,8 @@ public final class TraversalUtil {
 
     @SuppressWarnings("unchecked")
     public static <V> Iterator<V> filterResult(
-                                  List<HasContainer> hasContainers,
-                                  Iterator<? extends Element> iterator) {
+            List<HasContainer> hasContainers,
+            Iterator<? extends Element> iterator) {
         if (hasContainers.isEmpty()) {
             return (Iterator<V>) iterator;
         }
@@ -626,8 +626,8 @@ public final class TraversalUtil {
         // Extract all has steps in traversal
         @SuppressWarnings("rawtypes")
         List<HasStep> steps =
-                      TraversalHelper.getStepsOfAssignableClassRecursively(
-                      HasStep.class, traversal);
+                TraversalHelper.getStepsOfAssignableClassRecursively(
+                        HasStep.class, traversal);
 
         if (steps.isEmpty()) {
             return;
@@ -644,8 +644,8 @@ public final class TraversalUtil {
             }
 
             Optional<Graph> parentGraph = ((Traversal<?, ?>) traversal.getParent())
-                                                                      .asAdmin()
-                                                                      .getGraph();
+                    .asAdmin()
+                    .getGraph();
             if (parentGraph.filter(g -> !(g instanceof EmptyGraph)).isPresent()) {
                 traversal.setGraph(parentGraph.get());
             }
@@ -980,7 +980,7 @@ public final class TraversalUtil {
             }
 
             throw new HugeException(
-                      "Invalid value '%s', expect a number", e, value);
+                    "Invalid value '%s', expect a number", e, value);
         }
     }
 
@@ -1005,7 +1005,7 @@ public final class TraversalUtil {
                 continue;
             }
             throw new HugeException(
-                      "Invalid value '%s', expect a list of number", value);
+                    "Invalid value '%s', expect a list of number", value);
         }
         return values.toArray(new Number[0]);
     }
@@ -1016,7 +1016,7 @@ public final class TraversalUtil {
             return (V) JsonUtil.fromJson(value, Object.class);
         } catch (Exception e) {
             throw new HugeException(
-                      "Invalid value '%s', expect a single value", e, value);
+                    "Invalid value '%s', expect a single value", e, value);
         }
     }
 
@@ -1026,7 +1026,7 @@ public final class TraversalUtil {
             return JsonUtil.fromJson("[" + value + "]", List.class);
         } catch (Exception e) {
             throw new HugeException(
-                      "Invalid value '%s', expect a list", e, value);
+                    "Invalid value '%s', expect a list", e, value);
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/Nameable.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/Nameable.java
index f14c19dd2..cf8e71e6d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/Nameable.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/Nameable.java
@@ -20,6 +20,7 @@ package org.apache.hugegraph.type;
  * @author Matthias Broecheler (me@matthiasb.com)
  */
 public interface Nameable {
+
     /**
      * Returns the unique name of this entity.
      *
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/CollectionType.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/CollectionType.java
index 52d7a3ba1..e8a4cd354 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/CollectionType.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/CollectionType.java
@@ -60,7 +60,7 @@ public enum CollectionType implements SerialEnum {
                 return FU;
             default:
                 throw new AssertionError(
-                          "Unsupported collection code: " + code);
+                        "Unsupported collection code: " + code);
         }
     }
 }
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/DataType.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/DataType.java
index 69ebdbb64..2bfa93e7d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/DataType.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/DataType.java
@@ -22,9 +22,9 @@ import java.util.Date;
 import java.util.List;
 import java.util.UUID;
 
-import org.apache.hugegraph.util.Blob;
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.serializer.BytesBuffer;
+import org.apache.hugegraph.util.Blob;
 import org.apache.hugegraph.util.Bytes;
 import org.apache.hugegraph.util.DateUtil;
 import org.apache.hugegraph.util.JsonUtil;
@@ -132,13 +132,13 @@ public enum DataType implements SerialEnum {
                     break;
                 default:
                     throw new AssertionError(String.format(
-                              "Number type only contains Byte, Integer, " +
-                              "Long, Float, Double, but got %s", this.clazz()));
+                            "Number type only contains Byte, Integer, " +
+                            "Long, Float, Double, but got %s", this.clazz()));
             }
         } catch (NumberFormatException e) {
             throw new IllegalArgumentException(String.format(
-                      "Can't read '%s' as %s: %s",
-                      value, this.name, e.getMessage()));
+                    "Can't read '%s' as %s: %s",
+                    value, this.name, e.getMessage()));
         }
         return number;
     }
@@ -199,7 +199,7 @@ public enum DataType implements SerialEnum {
                     bytes[i] = ((Number) v).byteValue();
                 } else {
                     throw new IllegalArgumentException(String.format(
-                              "expect byte or int value, but got '%s'", v));
+                            "expect byte or int value, but got '%s'", v));
                 }
             }
             return Blob.wrap(bytes);
diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/Directions.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/Directions.java
index b2e18373b..1309cd89d 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/Directions.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/type/define/Directions.java
... 1027 lines suppressed ...