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Posted to commits@lucenenet.apache.org by ni...@apache.org on 2020/07/15 22:35:53 UTC

[lucenenet] 01/06: SWEEP: Removed fully-qualified namespace from System exception types and added using directives instead

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

nightowl888 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/lucenenet.git

commit c2d55219e5be0bf14fcce5094bdb05a7d04cf2f8
Author: Shad Storhaug <sh...@shadstorhaug.com>
AuthorDate: Thu Jul 16 02:00:32 2020 +0700

    SWEEP: Removed fully-qualified namespace from System exception types and added using directives instead
---
 .../Analysis/CommonGrams/CommonGramsFilter.cs      |  3 +-
 .../Analysis/CommonGrams/CommonGramsQueryFilter.cs |  2 +-
 .../Analysis/Hunspell/Dictionary.cs                |  4 +--
 .../Miscellaneous/HyphenatedWordsFilter.cs         |  3 +-
 .../Miscellaneous/Lucene47WordDelimiterFilter.cs   |  2 +-
 .../Analysis/Miscellaneous/PatternAnalyzer.cs      |  4 +--
 .../Analysis/Sinks/TeeSinkTokenFilter.cs           |  2 +-
 .../Analysis/Standard/ClassicTokenizerImpl.cs      |  2 +-
 .../Analysis/Standard/StandardTokenizerImpl.cs     |  2 +-
 .../ByTask/Feeds/QueryMaker.cs                     |  3 +-
 .../ByTask/Feeds/SimpleQueryMaker.cs               |  3 +-
 .../Support/Sax/Ext/Attributes2.cs                 |  4 +--
 .../Memory/DirectDocValuesProducer.cs              |  2 +-
 .../Memory/DirectPostingsFormat.cs                 |  2 +-
 src/Lucene.Net.Facet/Range/Range.cs                |  2 +-
 .../Taxonomy/Directory/DirectoryTaxonomyWriter.cs  |  2 +-
 .../Highlight/GradientFormatter.cs                 |  2 +-
 src/Lucene.Net.Memory/MemoryIndexNormDocValues.cs  |  6 ++--
 .../Http/Abstractions/IReplicationService.cs       |  6 ++--
 .../CharFilters/TestMappingCharFilterFactory.cs    |  2 +-
 .../Analysis/Core/TestClassicAnalyzer.cs           |  2 +-
 .../TestDemoExpressions.cs                         |  2 +-
 .../Taxonomy/TestTaxonomyCombined.cs               |  8 ++---
 .../IndexAndTaxonomyRevisionTest.cs                |  2 +-
 src/Lucene.Net.Tests/Index/TestAddIndexes.cs       |  4 +--
 .../Index/TestIndexWriterExceptions.cs             |  4 +--
 .../Index/TestIndexWriterMerging.cs                |  2 +-
 .../Index/TestIndexWriterWithThreads.cs            |  2 +-
 src/Lucene.Net.Tests/Index/TestReaderClosed.cs     |  4 +--
 src/Lucene.Net.Tests/Index/TestSegmentReader.cs    |  8 ++---
 src/Lucene.Net.Tests/Util/Packed/TestPackedInts.cs |  8 ++---
 .../Util/StressRamUsageEstimator.cs                |  4 +--
 src/Lucene.Net.Tests/Util/TestCharsRef.cs          |  4 +--
 .../Util/TestRamUsageEstimatorOnWildAnimals.cs     |  3 +-
 src/Lucene.Net.Tests/Util/TestUnicodeUtil.cs       |  2 +-
 src/Lucene.Net/Analysis/TokenFilter.cs             |  5 +--
 src/Lucene.Net/Codecs/Lucene40/BitVector.cs        |  8 ++---
 src/Lucene.Net/Index/ConcurrentMergeScheduler.cs   |  5 +--
 src/Lucene.Net/Index/DirectoryReader.cs            |  2 +-
 src/Lucene.Net/Index/DocValues.cs                  |  6 ++--
 src/Lucene.Net/Index/IndexWriter.cs                | 38 +++++++++++-----------
 src/Lucene.Net/Index/IndexWriterConfig.cs          |  2 +-
 src/Lucene.Net/Index/LiveIndexWriterConfig.cs      |  4 +--
 src/Lucene.Net/Index/SegmentReader.cs              |  3 +-
 src/Lucene.Net/Search/ConstantScoreQuery.cs        | 12 ++-----
 src/Lucene.Net/Search/FieldCacheImpl.cs            | 16 ++++-----
 src/Lucene.Net/Search/QueryWrapperFilter.cs        | 33 ++++++++++---------
 .../Search/Similarities/DFRSimilarity.cs           |  4 ++-
 src/Lucene.Net/Search/Weight.cs                    |  7 ++--
 src/Lucene.Net/Store/FSDirectory.cs                | 13 +++++---
 .../Store/RateLimitedDirectoryWrapper.cs           |  7 ++--
 src/Lucene.Net/Support/ConcurrentHashSet.cs        |  2 +-
 .../Document/Extensions/DocumentExtensions.cs      |  4 +--
 src/Lucene.Net/Util/ArrayUtil.cs                   | 16 ++++-----
 src/Lucene.Net/Util/Automaton/RegExp.cs            |  2 +-
 src/Lucene.Net/Util/BytesRefArray.cs               |  2 +-
 src/Lucene.Net/Util/CharsRef.cs                    |  4 +--
 src/Lucene.Net/Util/CommandLineUtil.cs             |  9 ++---
 src/Lucene.Net/Util/FieldCacheSanityChecker.cs     |  2 +-
 src/Lucene.Net/Util/NumericUtils.cs                |  8 ++---
 src/Lucene.Net/Util/Packed/Packed16ThreeBlocks.cs  |  2 +-
 src/Lucene.Net/Util/Packed/Packed8ThreeBlocks.cs   |  2 +-
 .../AspNetCoreReplicationRequest.cs                |  3 +-
 63 files changed, 175 insertions(+), 163 deletions(-)

diff --git a/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsFilter.cs b/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsFilter.cs
index 83e9985..941e369 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsFilter.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsFilter.cs
@@ -1,6 +1,7 @@
 using Lucene.Net.Analysis.TokenAttributes;
 using Lucene.Net.Analysis.Util;
 using Lucene.Net.Util;
+using System;
 using System.Text;
 
 namespace Lucene.Net.Analysis.CommonGrams
@@ -136,7 +137,7 @@ namespace Lucene.Net.Analysis.CommonGrams
         /// <para/>
         /// If you override this method, always call <c>base.Reset()</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on further usage).
+        /// throw <see cref="InvalidOperationException"/> on further usage).
         /// </summary>
         /// <remarks>
         /// <b>NOTE:</b>
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsQueryFilter.cs b/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsQueryFilter.cs
index d95751e..312aa6f 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsQueryFilter.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/CommonGrams/CommonGramsQueryFilter.cs
@@ -66,7 +66,7 @@ namespace Lucene.Net.Analysis.CommonGrams
         /// <para/>
         /// If you override this method, always call <c>base.Reset()</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on further usage).
+        /// throw <see cref="InvalidOperationException"/> on further usage).
         /// </summary>
         /// <remarks>
         /// <b>NOTE:</b>
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Hunspell/Dictionary.cs b/src/Lucene.Net.Analysis.Common/Analysis/Hunspell/Dictionary.cs
index 1d51453..80b83f5 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Hunspell/Dictionary.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Hunspell/Dictionary.cs
@@ -564,7 +564,7 @@ namespace Lucene.Net.Analysis.Hunspell
                 }
                 if (mappings.Put(parts[1], parts[2]) != null)
                 {
-                    throw new System.InvalidOperationException("duplicate mapping specified for: " + parts[1]);
+                    throw new InvalidOperationException("duplicate mapping specified for: " + parts[1]);
                 }
             }
 
@@ -993,7 +993,7 @@ namespace Lucene.Net.Analysis.Hunspell
             {
                 return aliases[id - 1];
             }
-            catch (System.IndexOutOfRangeException ex)
+            catch (IndexOutOfRangeException ex)
             {
                 throw new ArgumentException("Bad flag alias number:" + id, ex);
             }
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/HyphenatedWordsFilter.cs b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/HyphenatedWordsFilter.cs
index e12e123..156ae10 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/HyphenatedWordsFilter.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/HyphenatedWordsFilter.cs
@@ -1,4 +1,5 @@
 using Lucene.Net.Analysis.TokenAttributes;
+using System;
 using System.Text;
 
 namespace Lucene.Net.Analysis.Miscellaneous
@@ -147,7 +148,7 @@ namespace Lucene.Net.Analysis.Miscellaneous
         /// <para/>
         /// If you override this method, always call <c>base.Reset()</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on further usage).
+        /// throw <see cref="InvalidOperationException"/> on further usage).
         /// </summary>
         /// <remarks>
         /// <b>NOTE:</b>
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/Lucene47WordDelimiterFilter.cs b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/Lucene47WordDelimiterFilter.cs
index 2e0e21c..8af793d 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/Lucene47WordDelimiterFilter.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/Lucene47WordDelimiterFilter.cs
@@ -254,7 +254,7 @@ namespace Lucene.Net.Analysis.Miscellaneous
         /// <para/>
         /// If you override this method, always call <c>base.Reset()</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on further usage).
+        /// throw <see cref="InvalidOperationException"/> on further usage).
         /// </summary>
         /// <remarks>
         /// <b>NOTE:</b>
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/PatternAnalyzer.cs b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/PatternAnalyzer.cs
index 24b2dda..12b7166 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/PatternAnalyzer.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Miscellaneous/PatternAnalyzer.cs
@@ -376,7 +376,7 @@ namespace Lucene.Net.Analysis.Miscellaneous
             {
                 if (!initialized)
                 {
-                    throw new System.InvalidOperationException("Consumer did not call reset().");
+                    throw new InvalidOperationException("Consumer did not call reset().");
                 }
                 if (matcher == null)
                 {
@@ -493,7 +493,7 @@ namespace Lucene.Net.Analysis.Miscellaneous
             {
                 if (str == null)
                 {
-                    throw new System.InvalidOperationException("Consumer did not call reset().");
+                    throw new InvalidOperationException("Consumer did not call reset().");
                 }
                 ClearAttributes();
                 // cache loop instance vars (performance)
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Sinks/TeeSinkTokenFilter.cs b/src/Lucene.Net.Analysis.Common/Analysis/Sinks/TeeSinkTokenFilter.cs
index a0d6870..4320687 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Sinks/TeeSinkTokenFilter.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Sinks/TeeSinkTokenFilter.cs
@@ -219,7 +219,7 @@ namespace Lucene.Net.Analysis.Sinks
             {
                 if (it != null)
                 {
-                    throw new System.InvalidOperationException("The tee must be consumed before sinks are consumed.");
+                    throw new InvalidOperationException("The tee must be consumed before sinks are consumed.");
                 }
                 cachedStates.Add(state);
             }
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Standard/ClassicTokenizerImpl.cs b/src/Lucene.Net.Analysis.Common/Analysis/Standard/ClassicTokenizerImpl.cs
index 0e1a63f..0de05fd 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Standard/ClassicTokenizerImpl.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Standard/ClassicTokenizerImpl.cs
@@ -604,7 +604,7 @@ namespace Lucene.Net.Analysis.Standard
             {
                 message = ZZ_ERROR_MSG[errorCode];
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
             }
diff --git a/src/Lucene.Net.Analysis.Common/Analysis/Standard/StandardTokenizerImpl.cs b/src/Lucene.Net.Analysis.Common/Analysis/Standard/StandardTokenizerImpl.cs
index 4b9290b..ca34d71 100644
--- a/src/Lucene.Net.Analysis.Common/Analysis/Standard/StandardTokenizerImpl.cs
+++ b/src/Lucene.Net.Analysis.Common/Analysis/Standard/StandardTokenizerImpl.cs
@@ -1201,7 +1201,7 @@ namespace Lucene.Net.Analysis.Standard
             {
                 message = ZZ_ERROR_MSG[errorCode];
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
             }
diff --git a/src/Lucene.Net.Benchmark/ByTask/Feeds/QueryMaker.cs b/src/Lucene.Net.Benchmark/ByTask/Feeds/QueryMaker.cs
index b5d00ac..e33e358 100644
--- a/src/Lucene.Net.Benchmark/ByTask/Feeds/QueryMaker.cs
+++ b/src/Lucene.Net.Benchmark/ByTask/Feeds/QueryMaker.cs
@@ -1,5 +1,6 @@
 using Lucene.Net.Benchmarks.ByTask.Utils;
 using Lucene.Net.Search;
+using System;
 
 namespace Lucene.Net.Benchmarks.ByTask.Feeds
 {
@@ -30,7 +31,7 @@ namespace Lucene.Net.Benchmarks.ByTask.Feeds
         /// </summary>
         /// <param name="size">The size of the query - number of terms, etc.</param>
         /// <returns></returns>
-        /// <exception cref="System.Exception">If cannot make the query, or if size > 0 was specified but this feature is not supported.</exception>
+        /// <exception cref="Exception">If cannot make the query, or if size > 0 was specified but this feature is not supported.</exception>
         Query MakeQuery(int size);
 
         /// <summary>Create the next query</summary>
diff --git a/src/Lucene.Net.Benchmark/ByTask/Feeds/SimpleQueryMaker.cs b/src/Lucene.Net.Benchmark/ByTask/Feeds/SimpleQueryMaker.cs
index 1e88a00..130a3ab 100644
--- a/src/Lucene.Net.Benchmark/ByTask/Feeds/SimpleQueryMaker.cs
+++ b/src/Lucene.Net.Benchmark/ByTask/Feeds/SimpleQueryMaker.cs
@@ -4,6 +4,7 @@ using Lucene.Net.Index;
 using Lucene.Net.QueryParsers.Classic;
 using Lucene.Net.Search;
 using Lucene.Net.Util;
+using System;
 using System.Collections.Generic;
 
 namespace Lucene.Net.Benchmarks.ByTask.Feeds
@@ -36,7 +37,7 @@ namespace Lucene.Net.Benchmarks.ByTask.Feeds
         /// Extending classes can override this method for preparing different queries.
         /// </summary>
         /// <returns>Prepared queries.</returns>
-        /// <exception cref="System.Exception">If cannot prepare the queries.</exception>
+        /// <exception cref="Exception">If cannot prepare the queries.</exception>
         protected override Query[] PrepareQueries()
         {
             // analyzer (default is standard analyzer)
diff --git a/src/Lucene.Net.Benchmark/Support/Sax/Ext/Attributes2.cs b/src/Lucene.Net.Benchmark/Support/Sax/Ext/Attributes2.cs
index 6503fdb..07113b6 100644
--- a/src/Lucene.Net.Benchmark/Support/Sax/Ext/Attributes2.cs
+++ b/src/Lucene.Net.Benchmark/Support/Sax/Ext/Attributes2.cs
@@ -41,7 +41,7 @@ namespace Sax.Ext
         /// </summary>
         /// <param name="index">The attribute index (zero-based).</param>
         /// <returns>true if the attribute was declared in the DTD, false otherwise.</returns>
-        /// <exception cref="System.IndexOutOfRangeException">When the supplied index does not identify an attribute.</exception>
+        /// <exception cref="IndexOutOfRangeException">When the supplied index does not identify an attribute.</exception>
         bool IsDeclared(int index);
 
         /// <summary>
@@ -79,7 +79,7 @@ namespace Sax.Ext
         /// </summary>
         /// <param name="index">The attribute index (zero-based).</param>
         /// <returns>true if the value was found in the XML text, false if the value was provided by DTD defaulting.</returns>
-        /// <exception cref="System.IndexOutOfRangeException">When the supplied index does not identify an attribute.</exception>
+        /// <exception cref="IndexOutOfRangeException">When the supplied index does not identify an attribute.</exception>
         bool IsSpecified(int index);
 
         /// <summary>
diff --git a/src/Lucene.Net.Codecs/Memory/DirectDocValuesProducer.cs b/src/Lucene.Net.Codecs/Memory/DirectDocValuesProducer.cs
index 3db2dfd..bf5fa2e 100644
--- a/src/Lucene.Net.Codecs/Memory/DirectDocValuesProducer.cs
+++ b/src/Lucene.Net.Codecs/Memory/DirectDocValuesProducer.cs
@@ -271,7 +271,7 @@ namespace Lucene.Net.Codecs.Memory
                     }
 
                 default:
-                    throw new System.InvalidOperationException();
+                    throw new InvalidOperationException();
             }
         }
 
diff --git a/src/Lucene.Net.Codecs/Memory/DirectPostingsFormat.cs b/src/Lucene.Net.Codecs/Memory/DirectPostingsFormat.cs
index e5110c7..b92fb41 100644
--- a/src/Lucene.Net.Codecs/Memory/DirectPostingsFormat.cs
+++ b/src/Lucene.Net.Codecs/Memory/DirectPostingsFormat.cs
@@ -2278,7 +2278,7 @@ namespace Lucene.Net.Codecs.Memory
                     {
                         return docID = docIDs[upto];
                     }
-                    catch (System.IndexOutOfRangeException)
+                    catch (IndexOutOfRangeException)
                     {
                     }
                 }
diff --git a/src/Lucene.Net.Facet/Range/Range.cs b/src/Lucene.Net.Facet/Range/Range.cs
index 2c20df8..87c6351 100644
--- a/src/Lucene.Net.Facet/Range/Range.cs
+++ b/src/Lucene.Net.Facet/Range/Range.cs
@@ -40,7 +40,7 @@ namespace Lucene.Net.Facet.Range
         {
             if (label == null)
             {
-                throw new System.NullReferenceException("label cannot be null");
+                throw new NullReferenceException("label cannot be null");
             }
             this.Label = label;
         }
diff --git a/src/Lucene.Net.Facet/Taxonomy/Directory/DirectoryTaxonomyWriter.cs b/src/Lucene.Net.Facet/Taxonomy/Directory/DirectoryTaxonomyWriter.cs
index 4538906..540ed54 100644
--- a/src/Lucene.Net.Facet/Taxonomy/Directory/DirectoryTaxonomyWriter.cs
+++ b/src/Lucene.Net.Facet/Taxonomy/Directory/DirectoryTaxonomyWriter.cs
@@ -882,7 +882,7 @@ namespace Lucene.Net.Facet.Taxonomy.Directory
             // was allocated bigger than it really needs to be.
             if (ordinal >= nextID)
             {
-                throw new System.IndexOutOfRangeException("requested ordinal is bigger than the largest ordinal in the taxonomy");
+                throw new IndexOutOfRangeException("requested ordinal is bigger than the largest ordinal in the taxonomy");
             }
 
             int[] parents = GetTaxoArrays().Parents;
diff --git a/src/Lucene.Net.Highlighter/Highlight/GradientFormatter.cs b/src/Lucene.Net.Highlighter/Highlight/GradientFormatter.cs
index b3d18b9..180546c 100644
--- a/src/Lucene.Net.Highlighter/Highlight/GradientFormatter.cs
+++ b/src/Lucene.Net.Highlighter/Highlight/GradientFormatter.cs
@@ -208,7 +208,7 @@ namespace Lucene.Net.Search.Highlight
             try
             {
                 // LUCENENET NOTE: Convert.ToInt32(string, int) throws a
-                // System.FormatException if the character does not fall in
+                // FormatException if the character does not fall in
                 // the correct range, which is the behavior we are expecting.
                 // But throws an ArgumentException if passed a negative number.
                 // So we need to convert to FormatException to provide the correct behavior.
diff --git a/src/Lucene.Net.Memory/MemoryIndexNormDocValues.cs b/src/Lucene.Net.Memory/MemoryIndexNormDocValues.cs
index 9544945..a6dc2a9 100644
--- a/src/Lucene.Net.Memory/MemoryIndexNormDocValues.cs
+++ b/src/Lucene.Net.Memory/MemoryIndexNormDocValues.cs
@@ -1,4 +1,6 @@
-namespace Lucene.Net.Index.Memory
+using System;
+
+namespace Lucene.Net.Index.Memory
 {
     /*
      * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -33,7 +35,7 @@
         {
             if (docID != 0)
             {
-                throw new System.IndexOutOfRangeException();
+                throw new IndexOutOfRangeException();
             }
             else
             {
diff --git a/src/Lucene.Net.Replicator/Support/Http/Abstractions/IReplicationService.cs b/src/Lucene.Net.Replicator/Support/Http/Abstractions/IReplicationService.cs
index abbd46d..6d0c17c 100644
--- a/src/Lucene.Net.Replicator/Support/Http/Abstractions/IReplicationService.cs
+++ b/src/Lucene.Net.Replicator/Support/Http/Abstractions/IReplicationService.cs
@@ -1,4 +1,6 @@
-namespace Lucene.Net.Replicator.Http.Abstractions
+using System;
+
+namespace Lucene.Net.Replicator.Http.Abstractions
 {
     /*
      * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -25,7 +27,7 @@
         /// <summary>
         /// Executes the replication task.
         /// </summary>
-        /// <exception cref="System.InvalidOperationException">required parameters are missing</exception>
+        /// <exception cref="InvalidOperationException">required parameters are missing</exception>
         void Perform(IReplicationRequest request, IReplicationResponse response);
     }
 }
diff --git a/src/Lucene.Net.Tests.Analysis.Common/Analysis/CharFilters/TestMappingCharFilterFactory.cs b/src/Lucene.Net.Tests.Analysis.Common/Analysis/CharFilters/TestMappingCharFilterFactory.cs
index 2cc2a12..afe5b8c 100644
--- a/src/Lucene.Net.Tests.Analysis.Common/Analysis/CharFilters/TestMappingCharFilterFactory.cs
+++ b/src/Lucene.Net.Tests.Analysis.Common/Analysis/CharFilters/TestMappingCharFilterFactory.cs
@@ -56,7 +56,7 @@ namespace Lucene.Net.Analysis.CharFilters
                 f.ParseString("\\u123x");
                 fail("invalid hex number check.");
             }
-            catch (System.FormatException)
+            catch (FormatException)
             {
             }
         }
diff --git a/src/Lucene.Net.Tests.Analysis.Common/Analysis/Core/TestClassicAnalyzer.cs b/src/Lucene.Net.Tests.Analysis.Common/Analysis/Core/TestClassicAnalyzer.cs
index 7e66774..1c30cc8 100644
--- a/src/Lucene.Net.Tests.Analysis.Common/Analysis/Core/TestClassicAnalyzer.cs
+++ b/src/Lucene.Net.Tests.Analysis.Common/Analysis/Core/TestClassicAnalyzer.cs
@@ -129,7 +129,7 @@ namespace Lucene.Net.Analysis.Core
                 ClassicAnalyzer analyzer = new ClassicAnalyzer(TEST_VERSION_CURRENT);
                 AssertAnalyzesTo(analyzer, "www.nutch.org.", new string[] { "www.nutch.org" }, new string[] { "<HOST>" });
             }
-            catch (System.NullReferenceException)
+            catch (NullReferenceException)
             {
                 fail("Should not throw an NPE and it did");
             }
diff --git a/src/Lucene.Net.Tests.Expressions/TestDemoExpressions.cs b/src/Lucene.Net.Tests.Expressions/TestDemoExpressions.cs
index 9bff77a..c3d167f 100644
--- a/src/Lucene.Net.Tests.Expressions/TestDemoExpressions.cs
+++ b/src/Lucene.Net.Tests.Expressions/TestDemoExpressions.cs
@@ -176,7 +176,7 @@ namespace Lucene.Net.Expressions
 
         // TODO: ideally we'd test > Short.MAX_VALUE too, but compilation is currently recursive.
         // so if we want to test such huge expressions, we need to instead change parser to use an explicit Stack
-        /// <exception cref="System.Exception"></exception>
+        /// <exception cref="Exception"></exception>
         private void DoTestLotsOfBindings(int n)
         {
             SimpleBindings bindings = new SimpleBindings();
diff --git a/src/Lucene.Net.Tests.Facet/Taxonomy/TestTaxonomyCombined.cs b/src/Lucene.Net.Tests.Facet/Taxonomy/TestTaxonomyCombined.cs
index 8baeec1..980d5a9 100644
--- a/src/Lucene.Net.Tests.Facet/Taxonomy/TestTaxonomyCombined.cs
+++ b/src/Lucene.Net.Tests.Facet/Taxonomy/TestTaxonomyCombined.cs
@@ -517,7 +517,7 @@ namespace Lucene.Net.Facet.Taxonomy
                 tw.GetParent(-1);
                 fail("getParent for -1 should throw exception");
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 // ok
             }
@@ -526,7 +526,7 @@ namespace Lucene.Net.Facet.Taxonomy
                 tw.GetParent(TaxonomyReader.INVALID_ORDINAL);
                 fail("getParent for INVALID_ORDINAL should throw exception");
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 // ok
             }
@@ -535,7 +535,7 @@ namespace Lucene.Net.Facet.Taxonomy
                 int parent = tw.GetParent(tr.Count);
                 fail("getParent for getSize() should throw exception, but returned " + parent);
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 // ok
             }
@@ -953,7 +953,7 @@ namespace Lucene.Net.Facet.Taxonomy
                 Assert.AreEqual(TaxonomyReader.ROOT_ORDINAL, tr.ParallelTaxonomyArrays.Parents[author]);
                 // ok
             }
-            catch (System.IndexOutOfRangeException)
+            catch (IndexOutOfRangeException)
             {
                 fail("After category addition, commit() and refresh(), getParent for " + author + " should NOT throw exception");
             }
diff --git a/src/Lucene.Net.Tests.Replicator/IndexAndTaxonomyRevisionTest.cs b/src/Lucene.Net.Tests.Replicator/IndexAndTaxonomyRevisionTest.cs
index 942ad53..c27b126 100644
--- a/src/Lucene.Net.Tests.Replicator/IndexAndTaxonomyRevisionTest.cs
+++ b/src/Lucene.Net.Tests.Replicator/IndexAndTaxonomyRevisionTest.cs
@@ -54,7 +54,7 @@ namespace Lucene.Net.Replicator
                 assertNotNull(new IndexAndTaxonomyRevision(indexWriter, taxoWriter));
                 fail("should have failed when there are no commits to snapshot");
             }
-            catch (System.InvalidOperationException)
+            catch (InvalidOperationException)
             {
                 // expected
             }
diff --git a/src/Lucene.Net.Tests/Index/TestAddIndexes.cs b/src/Lucene.Net.Tests/Index/TestAddIndexes.cs
index bf712d2..62dad40 100644
--- a/src/Lucene.Net.Tests/Index/TestAddIndexes.cs
+++ b/src/Lucene.Net.Tests/Index/TestAddIndexes.cs
@@ -862,7 +862,7 @@ namespace Lucene.Net.Index
 
             internal override void Handle(Exception t)
             {
-                if (!(t is ObjectDisposedException) && !(t is System.NullReferenceException))
+                if (!(t is ObjectDisposedException) && !(t is NullReferenceException))
                 {
                     Console.Error.WriteLine(t.StackTrace);
                     lock (failures)
@@ -954,7 +954,7 @@ namespace Lucene.Net.Index
             {
                 bool report = true;
 
-                if (t is ObjectDisposedException || t is MergePolicy.MergeAbortedException || t is System.NullReferenceException)
+                if (t is ObjectDisposedException || t is MergePolicy.MergeAbortedException || t is NullReferenceException)
                 {
                     report = !didClose;
                 }
diff --git a/src/Lucene.Net.Tests/Index/TestIndexWriterExceptions.cs b/src/Lucene.Net.Tests/Index/TestIndexWriterExceptions.cs
index ebc0ec2..6ecf310 100644
--- a/src/Lucene.Net.Tests/Index/TestIndexWriterExceptions.cs
+++ b/src/Lucene.Net.Tests/Index/TestIndexWriterExceptions.cs
@@ -1240,7 +1240,7 @@ namespace Lucene.Net.Index
                 Assert.Fail("OutOfMemoryError expected");
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException expected)
+            catch (OutOfMemoryException expected)
 #pragma warning restore 168
             {
             }
@@ -1266,7 +1266,7 @@ namespace Lucene.Net.Index
             {
                 if (message.StartsWith("now flush at close", StringComparison.Ordinal) && thrown.CompareAndSet(false, true))
                 {
-                    throw new System.OutOfMemoryException("fake OOME at " + message);
+                    throw new OutOfMemoryException("fake OOME at " + message);
                 }
             }
 
diff --git a/src/Lucene.Net.Tests/Index/TestIndexWriterMerging.cs b/src/Lucene.Net.Tests/Index/TestIndexWriterMerging.cs
index 0d1ce4d..9faef06 100644
--- a/src/Lucene.Net.Tests/Index/TestIndexWriterMerging.cs
+++ b/src/Lucene.Net.Tests/Index/TestIndexWriterMerging.cs
@@ -465,7 +465,7 @@ namespace Lucene.Net.Index
                             break;
                         }
 #pragma warning disable 168
-                        catch (System.NullReferenceException e)
+                        catch (NullReferenceException e)
 #pragma warning restore 168
                         {
                             done = true;
diff --git a/src/Lucene.Net.Tests/Index/TestIndexWriterWithThreads.cs b/src/Lucene.Net.Tests/Index/TestIndexWriterWithThreads.cs
index 46b1788..b3208f6 100644
--- a/src/Lucene.Net.Tests/Index/TestIndexWriterWithThreads.cs
+++ b/src/Lucene.Net.Tests/Index/TestIndexWriterWithThreads.cs
@@ -807,7 +807,7 @@ namespace Lucene.Net.Index
                                 {
                                     // ok
                                 }
-                                catch (System.NullReferenceException)
+                                catch (NullReferenceException)
                                 {
                                     // ok
                                 }
diff --git a/src/Lucene.Net.Tests/Index/TestReaderClosed.cs b/src/Lucene.Net.Tests/Index/TestReaderClosed.cs
index a79a114..c95cbb1 100644
--- a/src/Lucene.Net.Tests/Index/TestReaderClosed.cs
+++ b/src/Lucene.Net.Tests/Index/TestReaderClosed.cs
@@ -74,7 +74,7 @@ namespace Lucene.Net.Index
                 searcher.Search(query, 5);
             }
 #pragma warning disable 168
-            catch (System.ObjectDisposedException ace)
+            catch (ObjectDisposedException ace)
 #pragma warning restore 168
             {
                 // expected
@@ -97,7 +97,7 @@ namespace Lucene.Net.Index
             {
                 searcher.Search(query, 5);
             }
-            catch (System.ObjectDisposedException ace)
+            catch (ObjectDisposedException ace)
             {
                 //Assert.AreEqual("this IndexReader cannot be used anymore as one of its child readers was closed", ace.Message);
                 // LUCENENET specific - ObjectDisposedExeption appends the type of object to the end of the message,
diff --git a/src/Lucene.Net.Tests/Index/TestSegmentReader.cs b/src/Lucene.Net.Tests/Index/TestSegmentReader.cs
index 4bd5d66..6330a9e 100644
--- a/src/Lucene.Net.Tests/Index/TestSegmentReader.cs
+++ b/src/Lucene.Net.Tests/Index/TestSegmentReader.cs
@@ -236,7 +236,7 @@ namespace Lucene.Net.Index
                 Assert.Fail();
             }
 #pragma warning disable 168
-            catch (System.IndexOutOfRangeException expected)
+            catch (IndexOutOfRangeException expected)
 #pragma warning restore 168
             {
             }
@@ -247,7 +247,7 @@ namespace Lucene.Net.Index
                 Assert.Fail();
             }
 #pragma warning disable 168
-            catch (System.IndexOutOfRangeException expected)
+            catch (IndexOutOfRangeException expected)
 #pragma warning restore 168
             {
             }
@@ -258,7 +258,7 @@ namespace Lucene.Net.Index
                 Assert.Fail();
             }
 #pragma warning disable 168
-            catch (System.IndexOutOfRangeException expected)
+            catch (IndexOutOfRangeException expected)
 #pragma warning restore 168
             {
             }
@@ -269,7 +269,7 @@ namespace Lucene.Net.Index
                 Assert.Fail();
             }
 #pragma warning disable 168
-            catch (System.IndexOutOfRangeException expected)
+            catch (IndexOutOfRangeException expected)
 #pragma warning restore 168
             {
             }
diff --git a/src/Lucene.Net.Tests/Util/Packed/TestPackedInts.cs b/src/Lucene.Net.Tests/Util/Packed/TestPackedInts.cs
index fc5765e..51ed3ac 100644
--- a/src/Lucene.Net.Tests/Util/Packed/TestPackedInts.cs
+++ b/src/Lucene.Net.Tests/Util/Packed/TestPackedInts.cs
@@ -518,7 +518,7 @@ namespace Lucene.Net.Util.Packed
                 p64 = new Packed64(INDEX, BITS);
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException oome)
+            catch (OutOfMemoryException oome)
 #pragma warning restore 168
             {
                 // this can easily happen: we're allocating a
@@ -540,7 +540,7 @@ namespace Lucene.Net.Util.Packed
                 p64sb = Packed64SingleBlock.Create(INDEX, BITS);
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException oome)
+            catch (OutOfMemoryException oome)
 #pragma warning restore 168
             {
                 // Ignore: see comment above
@@ -558,7 +558,7 @@ namespace Lucene.Net.Util.Packed
                 p8 = new Packed8ThreeBlocks(index);
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException oome)
+            catch (OutOfMemoryException oome)
 #pragma warning restore 168
             {
                 // Ignore: see comment above
@@ -577,7 +577,7 @@ namespace Lucene.Net.Util.Packed
                 p16 = new Packed16ThreeBlocks(index);
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException oome)
+            catch (OutOfMemoryException oome)
 #pragma warning restore 168
             {
                 // Ignore: see comment above
diff --git a/src/Lucene.Net.Tests/Util/StressRamUsageEstimator.cs b/src/Lucene.Net.Tests/Util/StressRamUsageEstimator.cs
index 82c9bb9..fe4e043 100644
--- a/src/Lucene.Net.Tests/Util/StressRamUsageEstimator.cs
+++ b/src/Lucene.Net.Tests/Util/StressRamUsageEstimator.cs
@@ -68,7 +68,7 @@ namespace Lucene.Net.Util
                 }
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException e)
+            catch (OutOfMemoryException e)
 #pragma warning restore 168
             {
                 // Release and quit.
@@ -151,7 +151,7 @@ namespace Lucene.Net.Util
                 }
             }
 #pragma warning disable 168
-            catch (System.OutOfMemoryException e)
+            catch (OutOfMemoryException e)
 #pragma warning restore 168
             {
                 // Release and quit.
diff --git a/src/Lucene.Net.Tests/Util/TestCharsRef.cs b/src/Lucene.Net.Tests/Util/TestCharsRef.cs
index a815a9d..c2a59b8 100644
--- a/src/Lucene.Net.Tests/Util/TestCharsRef.cs
+++ b/src/Lucene.Net.Tests/Util/TestCharsRef.cs
@@ -133,7 +133,7 @@ namespace Lucene.Net.Util
         //        c.CharAt(-1);
         //        Assert.Fail();
         //    }
-        //    catch (System.IndexOutOfRangeException expected)
+        //    catch (IndexOutOfRangeException expected)
         //    {
         //        // expected exception
         //    }
@@ -143,7 +143,7 @@ namespace Lucene.Net.Util
         //        c.CharAt(3);
         //        Assert.Fail();
         //    }
-        //    catch (System.IndexOutOfRangeException expected)
+        //    catch (IndexOutOfRangeException expected)
         //    {
         //        // expected exception
         //    }
diff --git a/src/Lucene.Net.Tests/Util/TestRamUsageEstimatorOnWildAnimals.cs b/src/Lucene.Net.Tests/Util/TestRamUsageEstimatorOnWildAnimals.cs
index c34ca84..eb3b54f 100644
--- a/src/Lucene.Net.Tests/Util/TestRamUsageEstimatorOnWildAnimals.cs
+++ b/src/Lucene.Net.Tests/Util/TestRamUsageEstimatorOnWildAnimals.cs
@@ -1,4 +1,5 @@
 using NUnit.Framework;
+using System;
 
 namespace Lucene.Net.Util
 {
@@ -53,7 +54,7 @@ namespace Lucene.Net.Util
                     lower = mid;
                 }
 #pragma warning disable 168
-                catch (System.StackOverflowException e)
+                catch (StackOverflowException e)
 #pragma warning restore 168
                 {
                     upper = mid;
diff --git a/src/Lucene.Net.Tests/Util/TestUnicodeUtil.cs b/src/Lucene.Net.Tests/Util/TestUnicodeUtil.cs
index 6a62994..b3a19d0 100644
--- a/src/Lucene.Net.Tests/Util/TestUnicodeUtil.cs
+++ b/src/Lucene.Net.Tests/Util/TestUnicodeUtil.cs
@@ -220,7 +220,7 @@ namespace Lucene.Net.Util
                     continue;
                 }
 #pragma warning disable 168
-                catch (System.IndexOutOfRangeException e1)
+                catch (IndexOutOfRangeException e1)
 #pragma warning restore 168
                 {
                     // Ignored.
diff --git a/src/Lucene.Net/Analysis/TokenFilter.cs b/src/Lucene.Net/Analysis/TokenFilter.cs
index c69d2d2..2b2d6c6 100644
--- a/src/Lucene.Net/Analysis/TokenFilter.cs
+++ b/src/Lucene.Net/Analysis/TokenFilter.cs
@@ -1,3 +1,4 @@
+using System;
 using System.IO;
 
 namespace Lucene.Net.Analysis
@@ -69,7 +70,7 @@ namespace Lucene.Net.Analysis
         /// <para/>
         /// If you override this method, always call <c>base.Dispose(disposing)</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on reuse).
+        /// throw <see cref="InvalidOperationException"/> on reuse).
         /// <para/>
         /// <b>NOTE:</b>
         /// The default implementation chains the call to the input TokenStream, so
@@ -92,7 +93,7 @@ namespace Lucene.Net.Analysis
         /// <para/>
         /// If you override this method, always call <c>base.Reset()</c>, otherwise
         /// some internal state will not be correctly reset (e.g., <see cref="Tokenizer"/> will
-        /// throw <see cref="System.InvalidOperationException"/> on further usage).
+        /// throw <see cref="InvalidOperationException"/> on further usage).
         /// </summary>
         /// <remarks>
         /// <b>NOTE:</b>
diff --git a/src/Lucene.Net/Codecs/Lucene40/BitVector.cs b/src/Lucene.Net/Codecs/Lucene40/BitVector.cs
index 87b8f7b..5d7dfbd 100644
--- a/src/Lucene.Net/Codecs/Lucene40/BitVector.cs
+++ b/src/Lucene.Net/Codecs/Lucene40/BitVector.cs
@@ -96,7 +96,7 @@ namespace Lucene.Net.Codecs.Lucene40
         {
             if (bit >= size)
             {
-                throw new System.IndexOutOfRangeException("bit=" + bit + " size=" + size);
+                throw new IndexOutOfRangeException("bit=" + bit + " size=" + size);
             }
             bits[bit >> 3] |= (byte)(1 << (bit & 7));
             count = -1;
@@ -110,7 +110,7 @@ namespace Lucene.Net.Codecs.Lucene40
         {
             if (bit >= size)
             {
-                throw new System.IndexOutOfRangeException("bit=" + bit + " size=" + size);
+                throw new IndexOutOfRangeException("bit=" + bit + " size=" + size);
             }
             int pos = bit >> 3;
             int v = bits[pos];
@@ -137,7 +137,7 @@ namespace Lucene.Net.Codecs.Lucene40
         {
             if (bit >= size)
             {
-                throw new System.IndexOutOfRangeException(bit.ToString());
+                throw new IndexOutOfRangeException(bit.ToString());
             }
             bits[bit >> 3] &= (byte)(~(1 << (bit & 7)));
             count = -1;
@@ -147,7 +147,7 @@ namespace Lucene.Net.Codecs.Lucene40
         {
             if (bit >= size)
             {
-                throw new System.IndexOutOfRangeException(bit.ToString());
+                throw new IndexOutOfRangeException(bit.ToString());
             }
             int pos = bit >> 3;
             int v = bits[pos];
diff --git a/src/Lucene.Net/Index/ConcurrentMergeScheduler.cs b/src/Lucene.Net/Index/ConcurrentMergeScheduler.cs
index dd72bc5..6be45ef 100644
--- a/src/Lucene.Net/Index/ConcurrentMergeScheduler.cs
+++ b/src/Lucene.Net/Index/ConcurrentMergeScheduler.cs
@@ -3,6 +3,7 @@ using J2N.Threading;
 using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
+using System.Security;
 using System.Text;
 using System.Threading;
 
@@ -599,12 +600,12 @@ namespace Lucene.Net.Index
                     Priority = priority;
                 }
 #pragma warning disable 168
-                catch (System.NullReferenceException npe)
+                catch (NullReferenceException npe)
                 {
                     // Strangely, Sun's JDK 1.5 on Linux sometimes
                     // throws NPE out of here...
                 }
-                catch (System.Security.SecurityException se)
+                catch (SecurityException se)
 #pragma warning restore 168
                 {
                     // Ignore this because we will still run fine with
diff --git a/src/Lucene.Net/Index/DirectoryReader.cs b/src/Lucene.Net/Index/DirectoryReader.cs
index c0b19e5..dd7f211 100644
--- a/src/Lucene.Net/Index/DirectoryReader.cs
+++ b/src/Lucene.Net/Index/DirectoryReader.cs
@@ -229,7 +229,7 @@ namespace Lucene.Net.Index
         /// <para><b>NOTE</b>: Once the writer is disposed, any
         /// outstanding readers may continue to be used.  However,
         /// if you attempt to reopen any of those readers, you'll
-        /// hit an <see cref="System.ObjectDisposedException"/>.</para>
+        /// hit an <see cref="ObjectDisposedException"/>.</para>
         /// 
         /// @lucene.experimental
         /// </summary>
diff --git a/src/Lucene.Net/Index/DocValues.cs b/src/Lucene.Net/Index/DocValues.cs
index 14d9ed9..cb43dad 100644
--- a/src/Lucene.Net/Index/DocValues.cs
+++ b/src/Lucene.Net/Index/DocValues.cs
@@ -1,3 +1,5 @@
+using System;
+
 namespace Lucene.Net.Index
 {
     /*
@@ -115,14 +117,14 @@ namespace Lucene.Net.Index
 
             public override void LookupOrd(long ord, BytesRef result)
             {
-                throw new System.IndexOutOfRangeException();
+                throw new IndexOutOfRangeException();
             }
 
             public override long ValueCount => 0;
 
             public override long OrdAt(int index)
             {
-                throw new System.IndexOutOfRangeException();
+                throw new IndexOutOfRangeException();
             }
 
             public override int Cardinality()
diff --git a/src/Lucene.Net/Index/IndexWriter.cs b/src/Lucene.Net/Index/IndexWriter.cs
index c8ab53b..ef56908 100644
--- a/src/Lucene.Net/Index/IndexWriter.cs
+++ b/src/Lucene.Net/Index/IndexWriter.cs
@@ -396,7 +396,7 @@ namespace Lucene.Net.Index
                             }
                         }
                     }
-                    catch (System.OutOfMemoryException oom)
+                    catch (OutOfMemoryException oom)
                     {
                         HandleOOM(oom, "getReader");
                         // never reached but javac disagrees:
@@ -1278,7 +1278,7 @@ namespace Lucene.Net.Index
                 }
                 Debug.Assert(docWriter.perThreadPool.NumDeactivatedThreadStates() == docWriter.perThreadPool.MaxThreadStates, "" + docWriter.perThreadPool.NumDeactivatedThreadStates() + " " + docWriter.perThreadPool.MaxThreadStates);
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "closeInternal");
             }
@@ -1577,7 +1577,7 @@ namespace Lucene.Net.Index
                     }
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "updateDocuments");
             }
@@ -1603,7 +1603,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "deleteDocuments(Term)");
             }
@@ -1727,7 +1727,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "deleteDocuments(Term..)");
             }
@@ -1753,7 +1753,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "deleteDocuments(Query)");
             }
@@ -1781,7 +1781,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "deleteDocuments(Query..)");
             }
@@ -1851,7 +1851,7 @@ namespace Lucene.Net.Index
                     }
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "updateDocument");
             }
@@ -1893,7 +1893,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "updateNumericDocValue");
             }
@@ -1939,7 +1939,7 @@ namespace Lucene.Net.Index
                     ProcessEvents(true, false);
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "updateBinaryDocValue");
             }
@@ -2591,7 +2591,7 @@ namespace Lucene.Net.Index
 
                 success = true;
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "rollbackInternal");
             }
@@ -2702,7 +2702,7 @@ namespace Lucene.Net.Index
                             globalFieldNumberMap.Clear();
                             success = true;
                         }
-                        catch (System.OutOfMemoryException oom)
+                        catch (OutOfMemoryException oom)
                         {
                             HandleOOM(oom, "deleteAll");
                         }
@@ -3133,7 +3133,7 @@ namespace Lucene.Net.Index
 
                 successTop = true;
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "addIndexes(Directory...)");
             }
@@ -3320,7 +3320,7 @@ namespace Lucene.Net.Index
                     Checkpoint();
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "addIndexes(IndexReader...)");
             }
@@ -3605,7 +3605,7 @@ namespace Lucene.Net.Index
                         }
                     }
                 }
-                catch (System.OutOfMemoryException oom)
+                catch (OutOfMemoryException oom)
                 {
                     HandleOOM(oom, "prepareCommit");
                 }
@@ -3894,7 +3894,7 @@ namespace Lucene.Net.Index
                     return anySegmentFlushed;
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "doFlush");
                 // never hit
@@ -4591,7 +4591,7 @@ namespace Lucene.Net.Index
                     }
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "merge");
             }
@@ -5542,7 +5542,7 @@ namespace Lucene.Net.Index
                     }
                 }
             }
-            catch (System.OutOfMemoryException oom)
+            catch (OutOfMemoryException oom)
             {
                 HandleOOM(oom, "startCommit");
             }
@@ -5605,7 +5605,7 @@ namespace Lucene.Net.Index
             public abstract void Warm(AtomicReader reader);
         }
 
-        private void HandleOOM(System.OutOfMemoryException oom, string location)
+        private void HandleOOM(OutOfMemoryException oom, string location)
         {
             if (infoStream.IsEnabled("IW"))
             {
diff --git a/src/Lucene.Net/Index/IndexWriterConfig.cs b/src/Lucene.Net/Index/IndexWriterConfig.cs
index 802644a..45dd161 100644
--- a/src/Lucene.Net/Index/IndexWriterConfig.cs
+++ b/src/Lucene.Net/Index/IndexWriterConfig.cs
@@ -431,7 +431,7 @@ namespace Lucene.Net.Index
                 {
                     return ((ThreadAffinityDocumentsWriterThreadPool)indexerThreadPool).MaxThreadStates;
                 }
-                catch (System.InvalidCastException cce)
+                catch (InvalidCastException cce)
                 {
                     throw new InvalidOperationException(cce.Message, cce);
                 }
diff --git a/src/Lucene.Net/Index/LiveIndexWriterConfig.cs b/src/Lucene.Net/Index/LiveIndexWriterConfig.cs
index a65b282..f031115 100644
--- a/src/Lucene.Net/Index/LiveIndexWriterConfig.cs
+++ b/src/Lucene.Net/Index/LiveIndexWriterConfig.cs
@@ -163,7 +163,7 @@ namespace Lucene.Net.Index
             codec = Codec.Default;
             if (codec == null)
             {
-                throw new System.NullReferenceException();
+                throw new NullReferenceException();
             }
             infoStream = Util.InfoStream.Default;
             mergePolicy = new TieredMergePolicy();
@@ -506,7 +506,7 @@ namespace Lucene.Net.Index
                 {
                     return ((ThreadAffinityDocumentsWriterThreadPool)indexerThreadPool).MaxThreadStates;
                 }
-                catch (System.InvalidCastException cce)
+                catch (InvalidCastException cce)
                 {
                     throw new InvalidOperationException(cce.Message, cce);
                 }
diff --git a/src/Lucene.Net/Index/SegmentReader.cs b/src/Lucene.Net/Index/SegmentReader.cs
index 4070bbc..ea01688 100644
--- a/src/Lucene.Net/Index/SegmentReader.cs
+++ b/src/Lucene.Net/Index/SegmentReader.cs
@@ -1,5 +1,6 @@
 using J2N.Runtime.CompilerServices;
 using Lucene.Net.Util;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
@@ -395,7 +396,7 @@ namespace Lucene.Net.Index
         {
             if (docID < 0 || docID >= MaxDoc)
             {
-                throw new System.IndexOutOfRangeException("docID must be >= 0 and < maxDoc=" + MaxDoc + " (got docID=" + docID + ")");
+                throw new IndexOutOfRangeException("docID must be >= 0 and < maxDoc=" + MaxDoc + " (got docID=" + docID + ")");
             }
         }
 
diff --git a/src/Lucene.Net/Search/ConstantScoreQuery.cs b/src/Lucene.Net/Search/ConstantScoreQuery.cs
index 7729124..1f73ff9 100644
--- a/src/Lucene.Net/Search/ConstantScoreQuery.cs
+++ b/src/Lucene.Net/Search/ConstantScoreQuery.cs
@@ -45,12 +45,8 @@ namespace Lucene.Net.Search
         /// </summary>
         public ConstantScoreQuery(Query query)
         {
-            if (query == null)
-            {
-                throw new System.NullReferenceException("Query may not be null");
-            }
             this.m_filter = null;
-            this.m_query = query;
+            this.m_query = query ?? throw new NullReferenceException("Query may not be null");
         }
 
         /// <summary>
@@ -62,11 +58,7 @@ namespace Lucene.Net.Search
         /// </summary>
         public ConstantScoreQuery(Filter filter)
         {
-            if (filter == null)
-            {
-                throw new System.NullReferenceException("Filter may not be null");
-            }
-            this.m_filter = filter;
+            this.m_filter = filter ?? throw new NullReferenceException("Filter may not be null");
             this.m_query = null;
         }
 
diff --git a/src/Lucene.Net/Search/FieldCacheImpl.cs b/src/Lucene.Net/Search/FieldCacheImpl.cs
index ac8aa7d..3e4049b 100644
--- a/src/Lucene.Net/Search/FieldCacheImpl.cs
+++ b/src/Lucene.Net/Search/FieldCacheImpl.cs
@@ -973,7 +973,7 @@ namespace Lucene.Net.Search
                         return wrapper.GetInt32s(reader, key.field, FieldCache.DEFAULT_INT32_PARSER, setDocsWithField);
 #pragma warning restore 612, 618
                     }
-                    catch (System.FormatException)
+                    catch (FormatException)
                     {
                         return wrapper.GetInt32s(reader, key.field, FieldCache.NUMERIC_UTILS_INT32_PARSER, setDocsWithField);
                     }
@@ -1023,7 +1023,7 @@ namespace Lucene.Net.Search
                     if (values == null)
                     {
                         // Lazy alloc so for the numeric field case
-                        // (which will hit a System.FormatException
+                        // (which will hit a FormatException
                         // when we first try the DEFAULT_INT32_PARSER),
                         // we don't double-alloc:
                         int startBitsPerValue;
@@ -1246,7 +1246,7 @@ namespace Lucene.Net.Search
                         return wrapper.GetSingles(reader, key.field, FieldCache.DEFAULT_SINGLE_PARSER, setDocsWithField);
 #pragma warning restore 612, 618
                     }
-                    catch (System.FormatException)
+                    catch (FormatException)
                     {
                         return wrapper.GetSingles(reader, key.field, FieldCache.NUMERIC_UTILS_SINGLE_PARSER, setDocsWithField);
                     }
@@ -1296,7 +1296,7 @@ namespace Lucene.Net.Search
                     if (values == null)
                     {
                         // Lazy alloc so for the numeric field case
-                        // (which will hit a System.FormatException
+                        // (which will hit a FormatException
                         // when we first try the DEFAULT_INT32_PARSER),
                         // we don't double-alloc:
                         values = new float[reader.MaxDoc];
@@ -1419,7 +1419,7 @@ namespace Lucene.Net.Search
                         return wrapper.GetInt64s(reader, key.field, FieldCache.DEFAULT_INT64_PARSER, setDocsWithField);
 #pragma warning restore 612, 618
                     }
-                    catch (System.FormatException)
+                    catch (FormatException)
                     {
                         return wrapper.GetInt64s(reader, key.field, FieldCache.NUMERIC_UTILS_INT64_PARSER, setDocsWithField);
                     }
@@ -1469,7 +1469,7 @@ namespace Lucene.Net.Search
                     if (values == null)
                     {
                         // Lazy alloc so for the numeric field case
-                        // (which will hit a System.FormatException
+                        // (which will hit a FormatException
                         // when we first try the DEFAULT_INT32_PARSER),
                         // we don't double-alloc:
                         int startBitsPerValue;
@@ -1594,7 +1594,7 @@ namespace Lucene.Net.Search
                         return wrapper.GetDoubles(reader, key.field, FieldCache.DEFAULT_DOUBLE_PARSER, setDocsWithField);
 #pragma warning restore 612, 618
                     }
-                    catch (System.FormatException)
+                    catch (FormatException)
                     {
                         return wrapper.GetDoubles(reader, key.field, FieldCache.NUMERIC_UTILS_DOUBLE_PARSER, setDocsWithField);
                     }
@@ -1643,7 +1643,7 @@ namespace Lucene.Net.Search
                     if (values == null)
                     {
                         // Lazy alloc so for the numeric field case
-                        // (which will hit a System.FormatException
+                        // (which will hit a FormatException
                         // when we first try the DEFAULT_INT32_PARSER),
                         // we don't double-alloc:
                         values = new double[reader.MaxDoc];
diff --git a/src/Lucene.Net/Search/QueryWrapperFilter.cs b/src/Lucene.Net/Search/QueryWrapperFilter.cs
index 5284053..95ebe61 100644
--- a/src/Lucene.Net/Search/QueryWrapperFilter.cs
+++ b/src/Lucene.Net/Search/QueryWrapperFilter.cs
@@ -1,21 +1,22 @@
 namespace Lucene.Net.Search
 {
+    using System;
     /*
-     * Licensed to the Apache Software Foundation (ASF) under one or more
-     * contributor license agreements.  See the NOTICE file distributed with
-     * this work for additional information regarding copyright ownership.
-     * The ASF licenses this file to You under the Apache License, Version 2.0
-     * (the "License"); you may not use this file except in compliance with
-     * the License.  You may obtain a copy of the License at
-     *
-     *     http://www.apache.org/licenses/LICENSE-2.0
-     *
-     * Unless required by applicable law or agreed to in writing, software
-     * distributed under the License is distributed on an "AS IS" BASIS,
-     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     * See the License for the specific language governing permissions and
-     * limitations under the License.
-     */
+* Licensed to the Apache Software Foundation (ASF) under one or more
+* contributor license agreements.  See the NOTICE file distributed with
+* this work for additional information regarding copyright ownership.
+* The ASF licenses this file to You under the Apache License, Version 2.0
+* (the "License"); you may not use this file except in compliance with
+* the License.  You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
 
     using AtomicReaderContext = Lucene.Net.Index.AtomicReaderContext;
     using IBits = Lucene.Net.Util.IBits;
@@ -41,7 +42,7 @@ namespace Lucene.Net.Search
         {
             if (query == null)
             {
-                throw new System.NullReferenceException("Query may not be null");
+                throw new NullReferenceException("Query may not be null");
             }
             this.query = query;
         }
diff --git a/src/Lucene.Net/Search/Similarities/DFRSimilarity.cs b/src/Lucene.Net/Search/Similarities/DFRSimilarity.cs
index f3c8129..172f4b3 100644
--- a/src/Lucene.Net/Search/Similarities/DFRSimilarity.cs
+++ b/src/Lucene.Net/Search/Similarities/DFRSimilarity.cs
@@ -1,3 +1,5 @@
+using System;
+
 namespace Lucene.Net.Search.Similarities
 {
     /*
@@ -110,7 +112,7 @@ namespace Lucene.Net.Search.Similarities
         {
             if (basicModel == null || afterEffect == null || normalization == null)
             {
-                throw new System.NullReferenceException("null parameters not allowed.");
+                throw new NullReferenceException("null parameters not allowed.");
             }
             this.m_basicModel = basicModel;
             this.m_afterEffect = afterEffect;
diff --git a/src/Lucene.Net/Search/Weight.cs b/src/Lucene.Net/Search/Weight.cs
index 3d974c4..3168f05 100644
--- a/src/Lucene.Net/Search/Weight.cs
+++ b/src/Lucene.Net/Search/Weight.cs
@@ -1,3 +1,4 @@
+using System;
 using System.IO;
 
 namespace Lucene.Net.Search
@@ -148,11 +149,7 @@ namespace Lucene.Net.Search
 
             public DefaultBulkScorer(Scorer scorer)
             {
-                if (scorer == null)
-                {
-                    throw new System.NullReferenceException();
-                }
-                this.scorer = scorer;
+                this.scorer = scorer ?? throw new NullReferenceException();
             }
 
             public override bool Score(ICollector collector, int max)
diff --git a/src/Lucene.Net/Store/FSDirectory.cs b/src/Lucene.Net/Store/FSDirectory.cs
index a13cb26..ecfdf1c 100644
--- a/src/Lucene.Net/Store/FSDirectory.cs
+++ b/src/Lucene.Net/Store/FSDirectory.cs
@@ -6,6 +6,9 @@ using System.Globalization;
 using System.IO;
 using System.Linq;// Used only for WRITE_LOCK_NAME in deprecated create=true case:
 using System.Runtime.CompilerServices;
+using System.Security;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace Lucene.Net.Store
 {
@@ -52,8 +55,8 @@ namespace Lucene.Net.Store
     ///         href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6265734">Sun
     ///         JRE bug</a> this is a poor choice for Windows, but
     ///         on all other platforms this is the preferred
-    ///         choice. Applications using <see cref="System.Threading.Thread.Interrupt()"/> or
-    ///         <see cref="System.Threading.Tasks.Task{TResult}"/> should use
+    ///         choice. Applications using <see cref="Thread.Interrupt()"/> or
+    ///         <see cref="Task{TResult}"/> should use
     ///         <see cref="SimpleFSDirectory"/> instead. See <see cref="NIOFSDirectory"/> java doc
     ///         for details.</description></item>
     ///
@@ -64,8 +67,8 @@ namespace Lucene.Net.Store
     ///         running on a 32 bit runtime but your index sizes are
     ///         small enough to fit into the virtual memory space.
     ///         <para/>
-    ///         Applications using <see cref="System.Threading.Thread.Interrupt()"/> or
-    ///         <see cref="System.Threading.Tasks.Task"/> should use
+    ///         Applications using <see cref="Thread.Interrupt()"/> or
+    ///         <see cref="Task{TResult}"/> should use
     ///         <see cref="SimpleFSDirectory"/> instead. See <see cref="MMapDirectory"/>
     ///         doc for details.</description></item>
     /// </list>
@@ -232,7 +235,7 @@ namespace Lucene.Net.Store
         /// <exception cref="DirectoryNotFoundException"> if the directory
         /// does not exist, or does exist but is not a
         /// directory or is invalid (for example, it is on an unmapped drive). </exception>
-        /// <exception cref="System.Security.SecurityException">The caller does not have the required permission.</exception>
+        /// <exception cref="SecurityException">The caller does not have the required permission.</exception>
         public static string[] ListAll(DirectoryInfo dir)
         {
             if (!System.IO.Directory.Exists(dir.FullName))
diff --git a/src/Lucene.Net/Store/RateLimitedDirectoryWrapper.cs b/src/Lucene.Net/Store/RateLimitedDirectoryWrapper.cs
index 4134b02..08bc05a 100644
--- a/src/Lucene.Net/Store/RateLimitedDirectoryWrapper.cs
+++ b/src/Lucene.Net/Store/RateLimitedDirectoryWrapper.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -87,7 +88,7 @@ namespace Lucene.Net.Store
         /// <para/>
         /// @lucene.experimental
         /// </summary>
-        /// <exception cref="System.ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
+        /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
         /// </exception>
         public void SetMaxWriteMBPerSec(double? mbPerSec, IOContext.UsageContext context)
         {
@@ -132,7 +133,7 @@ namespace Lucene.Net.Store
         /// <para/>
         /// @lucene.experimental
         /// </summary>
-        /// <exception cref="System.ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
+        /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
         /// </exception>
         public void SetRateLimiter(RateLimiter mergeWriteRateLimiter, IOContext.UsageContext context)
         {
@@ -145,7 +146,7 @@ namespace Lucene.Net.Store
         /// <para/>
         /// @lucene.experimental
         /// </summary>
-        /// <exception cref="System.ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
+        /// <exception cref="ObjectDisposedException"> if the <see cref="Directory"/> is already disposed
         /// </exception>
         public double GetMaxWriteMBPerSec(IOContext.UsageContext context)
         {
diff --git a/src/Lucene.Net/Support/ConcurrentHashSet.cs b/src/Lucene.Net/Support/ConcurrentHashSet.cs
index 389f1c4..60a18d6 100644
--- a/src/Lucene.Net/Support/ConcurrentHashSet.cs
+++ b/src/Lucene.Net/Support/ConcurrentHashSet.cs
@@ -282,7 +282,7 @@ namespace Lucene.Net.Support
         /// <param name="item">The item to add.</param>
         /// <returns>true if the items was added to the <see cref="ConcurrentHashSet{T}"/>
         /// successfully; false if it already exists.</returns>
-        /// <exception cref="T:System.OverflowException">The <see cref="ConcurrentHashSet{T}"/>
+        /// <exception cref="T:OverflowException">The <see cref="ConcurrentHashSet{T}"/>
         /// contains too many items.</exception>
         public bool Add(T item) =>
             AddInternal(item, _comparer.GetHashCode(item), true);
diff --git a/src/Lucene.Net/Support/Document/Extensions/DocumentExtensions.cs b/src/Lucene.Net/Support/Document/Extensions/DocumentExtensions.cs
index a70d096..8e43620 100644
--- a/src/Lucene.Net/Support/Document/Extensions/DocumentExtensions.cs
+++ b/src/Lucene.Net/Support/Document/Extensions/DocumentExtensions.cs
@@ -35,7 +35,7 @@ namespace Lucene.Net.Documents.Extensions
         /// </summary>
         /// <param name="document">This <see cref="Document"/>.</param>
         /// <param name="name">Field name</param>
-        /// <exception cref="System.InvalidCastException">If the field type cannot be cast to <typeparamref name="T"/>.</exception>
+        /// <exception cref="InvalidCastException">If the field type cannot be cast to <typeparamref name="T"/>.</exception>
         public static T GetField<T>(this Document document, string name) where T : IIndexableField
         {
             return (T)document.GetField(name);
@@ -49,7 +49,7 @@ namespace Lucene.Net.Documents.Extensions
         /// <param name="document">This <see cref="Document"/>.</param>
         /// <param name="name"> the name of the field </param>
         /// <returns> a <see cref="T:IndexableField[]"/> array </returns>
-        /// <exception cref="System.InvalidCastException">If the field type cannot be cast to <typeparam name="T"/>.</exception>
+        /// <exception cref="InvalidCastException">If the field type cannot be cast to <typeparam name="T"/>.</exception>
         public static T[] GetFields<T>(this Document document, string name) where T : IIndexableField
         {
             var fields = document.GetFields(name);
diff --git a/src/Lucene.Net/Util/ArrayUtil.cs b/src/Lucene.Net/Util/ArrayUtil.cs
index 610cad5..b13b0c0 100644
--- a/src/Lucene.Net/Util/ArrayUtil.cs
+++ b/src/Lucene.Net/Util/ArrayUtil.cs
@@ -97,17 +97,17 @@ namespace Lucene.Net.Util
             int minRadix = 2, maxRadix = 36;
             if (chars == null || radix < minRadix || radix > maxRadix)
             {
-                throw new System.FormatException();
+                throw new FormatException();
             }
             int i = 0;
             if (len == 0)
             {
-                throw new System.FormatException("chars length is 0");
+                throw new FormatException("chars length is 0");
             }
             bool negative = chars[offset + i] == '-';
             if (negative && ++i == len)
             {
-                throw new System.FormatException("can't convert to an int");
+                throw new FormatException("can't convert to an int");
             }
             if (negative == true)
             {
@@ -123,19 +123,19 @@ namespace Lucene.Net.Util
             int result = 0;
             for (int i = 0; i < len; i++)
             {
-                int digit = (int)System.Char.GetNumericValue(chars[i + offset]);
+                int digit = (int)char.GetNumericValue(chars[i + offset]);
                 if (digit == -1)
                 {
-                    throw new System.FormatException("Unable to parse");
+                    throw new FormatException("Unable to parse");
                 }
                 if (max > result)
                 {
-                    throw new System.FormatException("Unable to parse");
+                    throw new FormatException("Unable to parse");
                 }
                 int next = result * radix - digit;
                 if (next > result)
                 {
-                    throw new System.FormatException("Unable to parse");
+                    throw new FormatException("Unable to parse");
                 }
                 result = next;
             }
@@ -146,7 +146,7 @@ namespace Lucene.Net.Util
                 result = -result;
                 if (result < 0)
                 {
-                    throw new System.FormatException("Unable to parse");
+                    throw new FormatException("Unable to parse");
                 }
             }
             return result;
diff --git a/src/Lucene.Net/Util/Automaton/RegExp.cs b/src/Lucene.Net/Util/Automaton/RegExp.cs
index 06ba550..67e4c22 100644
--- a/src/Lucene.Net/Util/Automaton/RegExp.cs
+++ b/src/Lucene.Net/Util/Automaton/RegExp.cs
@@ -1263,7 +1263,7 @@ namespace Lucene.Net.Util.Automaton
                         return MakeInterval(imin, imax, digits);
                     }
 #pragma warning disable 168
-                    catch (System.FormatException e)
+                    catch (FormatException e)
 #pragma warning restore 168
                     {
                         throw new ArgumentException("interval syntax error at position " + (pos - 1), e);
diff --git a/src/Lucene.Net/Util/BytesRefArray.cs b/src/Lucene.Net/Util/BytesRefArray.cs
index f832be6..ac798af 100644
--- a/src/Lucene.Net/Util/BytesRefArray.cs
+++ b/src/Lucene.Net/Util/BytesRefArray.cs
@@ -103,7 +103,7 @@ namespace Lucene.Net.Util
                 pool.ReadBytes(offset, spare.Bytes, spare.Offset, spare.Length);
                 return spare;
             }
-            throw new System.IndexOutOfRangeException("index " + index + " must be less than the size: " + lastElement);
+            throw new IndexOutOfRangeException("index " + index + " must be less than the size: " + lastElement);
         }
 
         private int[] Sort(IComparer<BytesRef> comp)
diff --git a/src/Lucene.Net/Util/CharsRef.cs b/src/Lucene.Net/Util/CharsRef.cs
index 0301738..76c9704 100644
--- a/src/Lucene.Net/Util/CharsRef.cs
+++ b/src/Lucene.Net/Util/CharsRef.cs
@@ -281,7 +281,7 @@ namespace Lucene.Net.Util
         //    // NOTE: must do a real check here to meet the specs of CharSequence
         //    if (index < 0 || index >= Length)
         //    {
-        //        throw new System.IndexOutOfRangeException();
+        //        throw new IndexOutOfRangeException();
         //    }
         //    return Chars[Offset + index];
         //}
@@ -305,7 +305,7 @@ namespace Lucene.Net.Util
             // NOTE: must do a real check here to meet the specs of CharSequence
             //if (start < 0 || end > Length || start > end)
             //{
-            //    throw new System.IndexOutOfRangeException();
+            //    throw new IndexOutOfRangeException();
             //}
 
             // LUCENENET specific - changed semantics from start/end to startIndex/length to match .NET
diff --git a/src/Lucene.Net/Util/CommandLineUtil.cs b/src/Lucene.Net/Util/CommandLineUtil.cs
index e3f5e31..10d9129 100644
--- a/src/Lucene.Net/Util/CommandLineUtil.cs
+++ b/src/Lucene.Net/Util/CommandLineUtil.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Reflection;
 
 namespace Lucene.Net.Util
 {
@@ -48,7 +49,7 @@ namespace Lucene.Net.Util
             {
                 throw new ArgumentException(typeof(FSDirectory).Name + " implementation not found: " + clazzName, e);
             }
-            catch (System.InvalidCastException e)
+            catch (InvalidCastException e)
             {
                 throw new ArgumentException(clazzName + " is not a " + typeof(FSDirectory).Name + " implementation", e);
             }
@@ -66,7 +67,7 @@ namespace Lucene.Net.Util
         /// Loads a specific <see cref="Directory"/> implementation. </summary>
         /// <param name="clazzName"> The name of the <see cref="Directory"/> class to load. </param>
         /// <returns> The <see cref="Directory"/> class loaded. </returns>
-        /// <exception cref="System.TypeLoadException"> If the specified class cannot be found. </exception>
+        /// <exception cref="TypeLoadException"> If the specified class cannot be found. </exception>
         public static Type LoadDirectoryClass(string clazzName)
         {
             return Type.GetType(AdjustDirectoryClassName(clazzName));
@@ -76,7 +77,7 @@ namespace Lucene.Net.Util
         /// Loads a specific <see cref="FSDirectory"/> implementation. </summary>
         /// <param name="clazzName"> The name of the <see cref="FSDirectory"/> class to load. </param>
         /// <returns> The <see cref="FSDirectory"/> class loaded. </returns>
-        /// <exception cref="System.TypeLoadException"> If the specified class cannot be found. </exception>
+        /// <exception cref="TypeLoadException"> If the specified class cannot be found. </exception>
         public static Type LoadFSDirectoryClass(string clazzName)
         {
             return Type.GetType(AdjustDirectoryClassName(clazzName));
@@ -108,7 +109,7 @@ namespace Lucene.Net.Util
         /// <exception cref="MissingMethodException"> If the <see cref="Directory"/> does not have a constructor that takes <see cref="DirectoryInfo"/>. </exception>
         /// <exception cref="MemberAccessException"> If the class is abstract or an interface. </exception>
         /// <exception cref="TypeLoadException"> If the constructor does not have public visibility. </exception>
-        /// <exception cref="System.Reflection.TargetInvocationException"> If the constructor throws an exception </exception>
+        /// <exception cref="TargetInvocationException"> If the constructor throws an exception </exception>
         public static FSDirectory NewFSDirectory(Type clazz, DirectoryInfo dir)
         {
             // Assuming every FSDirectory has a ctor(File):
diff --git a/src/Lucene.Net/Util/FieldCacheSanityChecker.cs b/src/Lucene.Net/Util/FieldCacheSanityChecker.cs
index 5b002e3..de64801 100644
--- a/src/Lucene.Net/Util/FieldCacheSanityChecker.cs
+++ b/src/Lucene.Net/Util/FieldCacheSanityChecker.cs
@@ -319,7 +319,7 @@ namespace Lucene.Net.Util
                             }
                         }
                     }
-                    catch (System.ObjectDisposedException)
+                    catch (ObjectDisposedException)
                     {
                         // ignore this reader
                     }
diff --git a/src/Lucene.Net/Util/NumericUtils.cs b/src/Lucene.Net/Util/NumericUtils.cs
index 38582dd..d49a151 100644
--- a/src/Lucene.Net/Util/NumericUtils.cs
+++ b/src/Lucene.Net/Util/NumericUtils.cs
@@ -220,7 +220,7 @@ namespace Lucene.Net.Util
             int shift = val.Bytes[val.Offset] - SHIFT_START_INT64;
             if (shift > 63 || shift < 0)
             {
-                throw new System.FormatException("Invalid shift value (" + shift + ") in prefixCoded bytes (is encoded value really an INT?)");
+                throw new FormatException("Invalid shift value (" + shift + ") in prefixCoded bytes (is encoded value really an INT?)");
             }
             return shift;
         }
@@ -238,7 +238,7 @@ namespace Lucene.Net.Util
             int shift = val.Bytes[val.Offset] - SHIFT_START_INT32;
             if (shift > 31 || shift < 0)
             {
-                throw new System.FormatException("Invalid shift value in prefixCoded bytes (is encoded value really an INT?)");
+                throw new FormatException("Invalid shift value in prefixCoded bytes (is encoded value really an INT?)");
             }
             return shift;
         }
@@ -262,7 +262,7 @@ namespace Lucene.Net.Util
                 var b = val.Bytes[i];
                 if (b < 0)
                 {
-                    throw new System.FormatException("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
+                    throw new FormatException("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
                 }
                 sortableBits |= (byte)b;
             }
@@ -288,7 +288,7 @@ namespace Lucene.Net.Util
                 var b = val.Bytes[i];
                 if (b < 0)
                 {
-                    throw new System.FormatException("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
+                    throw new FormatException("Invalid prefixCoded numerical value representation (byte " + (b & 0xff).ToString("x") + " at position " + (i - val.Offset) + " is invalid)");
                 }
                 sortableBits |= b;
             }
diff --git a/src/Lucene.Net/Util/Packed/Packed16ThreeBlocks.cs b/src/Lucene.Net/Util/Packed/Packed16ThreeBlocks.cs
index a152c90..d5579ab 100644
--- a/src/Lucene.Net/Util/Packed/Packed16ThreeBlocks.cs
+++ b/src/Lucene.Net/Util/Packed/Packed16ThreeBlocks.cs
@@ -41,7 +41,7 @@ namespace Lucene.Net.Util.Packed
         {
             if (valueCount > MAX_SIZE)
             {
-                throw new System.IndexOutOfRangeException("MAX_SIZE exceeded");
+                throw new IndexOutOfRangeException("MAX_SIZE exceeded");
             }
             blocks = new short[valueCount * 3];
         }
diff --git a/src/Lucene.Net/Util/Packed/Packed8ThreeBlocks.cs b/src/Lucene.Net/Util/Packed/Packed8ThreeBlocks.cs
index 5fe7079..a5a08ae 100644
--- a/src/Lucene.Net/Util/Packed/Packed8ThreeBlocks.cs
+++ b/src/Lucene.Net/Util/Packed/Packed8ThreeBlocks.cs
@@ -41,7 +41,7 @@ namespace Lucene.Net.Util.Packed
         {
             if (valueCount > MAX_SIZE)
             {
-                throw new System.IndexOutOfRangeException("MAX_SIZE exceeded");
+                throw new IndexOutOfRangeException("MAX_SIZE exceeded");
             }
             blocks = new byte[valueCount * 3];
         }
diff --git a/src/dotnet/Lucene.Net.Replicator.AspNetCore/AspNetCoreReplicationRequest.cs b/src/dotnet/Lucene.Net.Replicator.AspNetCore/AspNetCoreReplicationRequest.cs
index b3cef44..61893bb 100644
--- a/src/dotnet/Lucene.Net.Replicator.AspNetCore/AspNetCoreReplicationRequest.cs
+++ b/src/dotnet/Lucene.Net.Replicator.AspNetCore/AspNetCoreReplicationRequest.cs
@@ -1,5 +1,6 @@
 using Lucene.Net.Replicator.Http.Abstractions;
 using Microsoft.AspNetCore.Http;
+using System;
 using System.Linq;
 
 namespace Lucene.Net.Replicator.AspNetCore
@@ -52,7 +53,7 @@ namespace Lucene.Net.Replicator.AspNetCore
         /// </summary>
         /// <param name="name">the name of the requested parameter</param>
         /// <returns>the value of the requested parameter or null if not present</returns>
-        /// <exception cref="System.InvalidOperationException">More than one parameter with the name was given.</exception>
+        /// <exception cref="InvalidOperationException">More than one parameter with the name was given.</exception>
         public string QueryParam(string name)
         {
             return request.Query[name].SingleOrDefault();