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Posted to commits@zeppelin.apache.org by jo...@apache.org on 2018/08/26 04:44:25 UTC

[42/49] zeppelin git commit: [ZEPPELIN-3740] Adopt `google-java-format` and `fmt-maven-plugin`

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
index 95674ea..4c21136 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
@@ -20,7 +20,22 @@ package org.apache.zeppelin.livy;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.annotations.SerializedName;
-
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.security.KeyStore;
+import java.security.Principal;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import javax.net.ssl.SSLContext;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.exception.ExceptionUtils;
 import org.apache.http.auth.AuthSchemeProvider;
@@ -38,6 +53,13 @@ import org.apache.http.impl.auth.SPNegoSchemeFactory;
 import org.apache.http.impl.client.BasicCredentialsProvider;
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.impl.client.HttpClients;
+import org.apache.zeppelin.interpreter.Interpreter;
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.interpreter.InterpreterException;
+import org.apache.zeppelin.interpreter.InterpreterResult;
+import org.apache.zeppelin.interpreter.InterpreterResultMessage;
+import org.apache.zeppelin.interpreter.InterpreterUtils;
+import org.apache.zeppelin.interpreter.thrift.InterpreterCompletion;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.http.HttpEntity;
@@ -53,35 +75,7 @@ import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.nio.charset.Charset;
-import java.security.KeyStore;
-import java.security.Principal;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Properties;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-import javax.net.ssl.SSLContext;
-
-import org.apache.zeppelin.interpreter.Interpreter;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.interpreter.InterpreterException;
-import org.apache.zeppelin.interpreter.InterpreterResult;
-import org.apache.zeppelin.interpreter.InterpreterResultMessage;
-import org.apache.zeppelin.interpreter.InterpreterUtils;
-import org.apache.zeppelin.interpreter.thrift.InterpreterCompletion;
-
-/**
- * Base class for livy interpreters.
- */
+/** Base class for livy interpreters. */
 public abstract class BaseLivyInterpreter extends Interpreter {
 
   protected static final Logger LOGGER = LoggerFactory.getLogger(BaseLivyInterpreter.class);
@@ -102,32 +96,34 @@ public abstract class BaseLivyInterpreter extends Interpreter {
   // delegate to sharedInterpreter when it is available
   protected LivySharedInterpreter sharedInterpreter;
 
-  Set<Object> paragraphsToCancel = Collections.newSetFromMap(
-      new ConcurrentHashMap<Object, Boolean>());
+  Set<Object> paragraphsToCancel =
+      Collections.newSetFromMap(new ConcurrentHashMap<Object, Boolean>());
   private ConcurrentHashMap<String, Integer> paragraphId2StmtProgressMap =
       new ConcurrentHashMap<>();
 
   public BaseLivyInterpreter(Properties property) {
     super(property);
     this.livyURL = property.getProperty("zeppelin.livy.url");
-    this.displayAppInfo = Boolean.parseBoolean(
-        property.getProperty("zeppelin.livy.displayAppInfo", "true"));
-    this.restartDeadSession = Boolean.parseBoolean(
-        property.getProperty("zeppelin.livy.restart_dead_session", "false"));
-    this.sessionCreationTimeout = Integer.parseInt(
-        property.getProperty("zeppelin.livy.session.create_timeout", 120 + ""));
-    this.pullStatusInterval = Integer.parseInt(
-        property.getProperty("zeppelin.livy.pull_status.interval.millis", 1000 + ""));
-    this.maxLogLines = Integer.parseInt(property.getProperty("zeppelin.livy.maxLogLines",
-        "1000"));
+    this.displayAppInfo =
+        Boolean.parseBoolean(property.getProperty("zeppelin.livy.displayAppInfo", "true"));
+    this.restartDeadSession =
+        Boolean.parseBoolean(property.getProperty("zeppelin.livy.restart_dead_session", "false"));
+    this.sessionCreationTimeout =
+        Integer.parseInt(property.getProperty("zeppelin.livy.session.create_timeout", 120 + ""));
+    this.pullStatusInterval =
+        Integer.parseInt(
+            property.getProperty("zeppelin.livy.pull_status.interval.millis", 1000 + ""));
+    this.maxLogLines = Integer.parseInt(property.getProperty("zeppelin.livy.maxLogLines", "1000"));
     this.restTemplate = createRestTemplate();
     if (!StringUtils.isBlank(property.getProperty("zeppelin.livy.http.headers"))) {
       String[] headers = property.getProperty("zeppelin.livy.http.headers").split(";");
       for (String header : headers) {
         String[] splits = header.split(":", -1);
         if (splits.length != 2) {
-          throw new RuntimeException("Invalid format of http headers: " + header +
-              ", valid http header format is HEADER_NAME:HEADER_VALUE");
+          throw new RuntimeException(
+              "Invalid format of http headers: "
+                  + header
+                  + ", valid http header format is HEADER_NAME:HEADER_VALUE");
         }
         customHeaders.put(splits[0].trim(), envSubstitute(splits[1].trim()));
       }
@@ -163,8 +159,8 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         initLivySession();
       }
     } catch (LivyException e) {
-      String msg = "Fail to create session, please check livy interpreter log and " +
-          "livy server log";
+      String msg =
+          "Fail to create session, please check livy interpreter log and " + "livy server log";
       throw new InterpreterException(msg, e);
     }
   }
@@ -191,14 +187,17 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         sessionInfo.appId = extractAppId();
       }
 
-      if (sessionInfo.appInfo == null ||
-          StringUtils.isEmpty(sessionInfo.appInfo.get("sparkUiUrl"))) {
+      if (sessionInfo.appInfo == null
+          || StringUtils.isEmpty(sessionInfo.appInfo.get("sparkUiUrl"))) {
         sessionInfo.webUIAddress = extractWebUIAddress();
       } else {
         sessionInfo.webUIAddress = sessionInfo.appInfo.get("sparkUiUrl");
       }
-      LOGGER.info("Create livy session successfully with sessionId: {}, appId: {}, webUI: {}",
-          sessionInfo.id, sessionInfo.appId, sessionInfo.webUIAddress);
+      LOGGER.info(
+          "Create livy session successfully with sessionId: {}, appId: {}, webUI: {}",
+          sessionInfo.id,
+          sessionInfo.appId,
+          sessionInfo.webUIAddress);
     } else {
       LOGGER.info("Create livy session successfully with sessionId: {}", this.sessionInfo.id);
     }
@@ -235,20 +234,20 @@ public abstract class BaseLivyInterpreter extends Interpreter {
       return interpret(st, null, context.getParagraphId(), this.displayAppInfo, true, true);
     } catch (LivyException e) {
       LOGGER.error("Fail to interpret:" + st, e);
-      return new InterpreterResult(InterpreterResult.Code.ERROR,
-          InterpreterUtils.getMostRelevantMessage(e));
+      return new InterpreterResult(
+          InterpreterResult.Code.ERROR, InterpreterUtils.getMostRelevantMessage(e));
     }
   }
 
   @Override
-  public List<InterpreterCompletion> completion(String buf, int cursor,
-      InterpreterContext interpreterContext) {
+  public List<InterpreterCompletion> completion(
+      String buf, int cursor, InterpreterContext interpreterContext) {
     List<InterpreterCompletion> candidates = Collections.emptyList();
     try {
       candidates = callCompletion(new CompletionRequest(buf, getSessionKind(), cursor));
     } catch (SessionNotFoundException e) {
-      LOGGER.warn("Livy session {} is expired. Will return empty list of candidates.",
-          getSessionInfo().id);
+      LOGGER.warn(
+          "Livy session {} is expired. Will return empty list of candidates.", getSessionInfo().id);
     } catch (LivyException le) {
       logger.error("Failed to call code completions. Will return empty list of candidates", le);
     }
@@ -258,8 +257,10 @@ public abstract class BaseLivyInterpreter extends Interpreter {
   private List<InterpreterCompletion> callCompletion(CompletionRequest req) throws LivyException {
     List<InterpreterCompletion> candidates = new ArrayList<>();
     try {
-      CompletionResponse resp = CompletionResponse.fromJson(
-          callRestAPI("/sessions/" + getSessionInfo().id + "/completion", "POST", req.toJson()));
+      CompletionResponse resp =
+          CompletionResponse.fromJson(
+              callRestAPI(
+                  "/sessions/" + getSessionInfo().id + "/completion", "POST", req.toJson()));
       for (String candidate : resp.candidates) {
         candidates.add(new InterpreterCompletion(candidate, candidate, StringUtils.EMPTY));
       }
@@ -298,37 +299,51 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     return 0;
   }
 
-  private SessionInfo createSession(String user, String kind)
-      throws LivyException {
+  private SessionInfo createSession(String user, String kind) throws LivyException {
     try {
       Map<String, String> conf = new HashMap<>();
       for (Map.Entry<Object, Object> entry : getProperties().entrySet()) {
-        if (entry.getKey().toString().startsWith("livy.spark.") &&
-            !entry.getValue().toString().isEmpty()) {
+        if (entry.getKey().toString().startsWith("livy.spark.")
+            && !entry.getValue().toString().isEmpty()) {
           conf.put(entry.getKey().toString().substring(5), entry.getValue().toString());
         }
       }
 
-      CreateSessionRequest request = new CreateSessionRequest(kind,
-          user == null || user.equals("anonymous") ? null : user, conf);
-      SessionInfo sessionInfo = SessionInfo.fromJson(
-          callRestAPI("/sessions", "POST", request.toJson()));
+      CreateSessionRequest request =
+          new CreateSessionRequest(
+              kind, user == null || user.equals("anonymous") ? null : user, conf);
+      SessionInfo sessionInfo =
+          SessionInfo.fromJson(callRestAPI("/sessions", "POST", request.toJson()));
       long start = System.currentTimeMillis();
       // pull the session status until it is idle or timeout
       while (!sessionInfo.isReady()) {
         if ((System.currentTimeMillis() - start) / 1000 > sessionCreationTimeout) {
-          String msg = "The creation of session " + sessionInfo.id + " is timeout within "
-              + sessionCreationTimeout + " seconds, appId: " + sessionInfo.appId
-              + ", log:\n" + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
+          String msg =
+              "The creation of session "
+                  + sessionInfo.id
+                  + " is timeout within "
+                  + sessionCreationTimeout
+                  + " seconds, appId: "
+                  + sessionInfo.appId
+                  + ", log:\n"
+                  + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
           throw new LivyException(msg);
         }
         Thread.sleep(pullStatusInterval);
         sessionInfo = getSessionInfo(sessionInfo.id);
-        LOGGER.info("Session {} is in state {}, appId {}", sessionInfo.id, sessionInfo.state,
+        LOGGER.info(
+            "Session {} is in state {}, appId {}",
+            sessionInfo.id,
+            sessionInfo.state,
             sessionInfo.appId);
         if (sessionInfo.isFinished()) {
-          String msg = "Session " + sessionInfo.id + " is finished, appId: " + sessionInfo.appId
-              + ", log:\n" + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
+          String msg =
+              "Session "
+                  + sessionInfo.id
+                  + " is finished, appId: "
+                  + sessionInfo.appId
+                  + ", log:\n"
+                  + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
           throw new LivyException(msg);
         }
       }
@@ -344,25 +359,34 @@ public abstract class BaseLivyInterpreter extends Interpreter {
   }
 
   private SessionLog getSessionLog(int sessionId) throws LivyException {
-    return SessionLog.fromJson(callRestAPI("/sessions/" + sessionId + "/log?size=" + maxLogLines,
-        "GET"));
+    return SessionLog.fromJson(
+        callRestAPI("/sessions/" + sessionId + "/log?size=" + maxLogLines, "GET"));
   }
 
-  public InterpreterResult interpret(String code,
-                                     String paragraphId,
-                                     boolean displayAppInfo,
-                                     boolean appendSessionExpired,
-                                     boolean appendSessionDead) throws LivyException {
-    return interpret(code, sharedInterpreter.isSupported() ? getSessionKind() : null,
-        paragraphId, displayAppInfo, appendSessionExpired, appendSessionDead);
-  }
-
-  public InterpreterResult interpret(String code,
-                                     String codeType,
-                                     String paragraphId,
-                                     boolean displayAppInfo,
-                                     boolean appendSessionExpired,
-                                     boolean appendSessionDead) throws LivyException {
+  public InterpreterResult interpret(
+      String code,
+      String paragraphId,
+      boolean displayAppInfo,
+      boolean appendSessionExpired,
+      boolean appendSessionDead)
+      throws LivyException {
+    return interpret(
+        code,
+        sharedInterpreter.isSupported() ? getSessionKind() : null,
+        paragraphId,
+        displayAppInfo,
+        appendSessionExpired,
+        appendSessionDead);
+  }
+
+  public InterpreterResult interpret(
+      String code,
+      String codeType,
+      String paragraphId,
+      boolean displayAppInfo,
+      boolean appendSessionExpired,
+      boolean appendSessionDead)
+      throws LivyException {
     StatementInfo stmtInfo = null;
     boolean sessionExpired = false;
     boolean sessionDead = false;
@@ -393,8 +417,9 @@ public abstract class BaseLivyInterpreter extends Interpreter {
           }
           stmtInfo = executeStatement(new ExecuteRequest(code, codeType));
         } else {
-          throw new LivyException("%html <font color=\"red\">Livy session is dead somehow, " +
-              "please check log to see why it is dead, and then restart livy interpreter</font>");
+          throw new LivyException(
+              "%html <font color=\"red\">Livy session is dead somehow, "
+                  + "please check log to see why it is dead, and then restart livy interpreter</font>");
         }
       }
 
@@ -416,8 +441,8 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         }
       }
       if (appendSessionExpired || appendSessionDead) {
-        return appendSessionExpireDead(getResultFromStatementInfo(stmtInfo, displayAppInfo),
-            sessionExpired, sessionDead);
+        return appendSessionExpireDead(
+            getResultFromStatementInfo(stmtInfo, displayAppInfo), sessionExpired, sessionDead);
       } else {
         return getResultFromStatementInfo(stmtInfo, displayAppInfo);
       }
@@ -460,20 +485,20 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     }
   }
 
-  private InterpreterResult appendSessionExpireDead(InterpreterResult result,
-                                                    boolean sessionExpired,
-                                                    boolean sessionDead) {
+  private InterpreterResult appendSessionExpireDead(
+      InterpreterResult result, boolean sessionExpired, boolean sessionDead) {
     InterpreterResult result2 = new InterpreterResult(result.code());
     if (sessionExpired) {
-      result2.add(InterpreterResult.Type.HTML,
-          "<font color=\"red\">Previous livy session is expired, new livy session is created. " +
-              "Paragraphs that depend on this paragraph need to be re-executed!</font>");
-
+      result2.add(
+          InterpreterResult.Type.HTML,
+          "<font color=\"red\">Previous livy session is expired, new livy session is created. "
+              + "Paragraphs that depend on this paragraph need to be re-executed!</font>");
     }
     if (sessionDead) {
-      result2.add(InterpreterResult.Type.HTML,
-          "<font color=\"red\">Previous livy session is dead, new livy session is created. " +
-              "Paragraphs that depend on this paragraph need to be re-executed!</font>");
+      result2.add(
+          InterpreterResult.Type.HTML,
+          "<font color=\"red\">Previous livy session is dead, new livy session is created. "
+              + "Paragraphs that depend on this paragraph need to be re-executed!</font>");
     }
 
     for (InterpreterResultMessage message : result.message()) {
@@ -482,8 +507,8 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     return result2;
   }
 
-  private InterpreterResult getResultFromStatementInfo(StatementInfo stmtInfo,
-                                                       boolean displayAppInfo) {
+  private InterpreterResult getResultFromStatementInfo(
+      StatementInfo stmtInfo, boolean displayAppInfo) {
     if (stmtInfo.output != null && stmtInfo.output.isError()) {
       InterpreterResult result = new InterpreterResult(InterpreterResult.Code.ERROR);
       StringBuilder sb = new StringBuilder();
@@ -505,7 +530,7 @@ public abstract class BaseLivyInterpreter extends Interpreter {
       // This case should never happen, just in case
       return new InterpreterResult(InterpreterResult.Code.ERROR, "Empty output");
     } else {
-      //TODO(zjffdu) support other types of data (like json, image and etc)
+      // TODO(zjffdu) support other types of data (like json, image and etc)
       String result = stmtInfo.output.data.plainText;
 
       // check table magic result first
@@ -526,11 +551,13 @@ public abstract class BaseLivyInterpreter extends Interpreter {
           outputBuilder.append(StringUtils.join(row, "\t"));
           outputBuilder.append("\n");
         }
-        return new InterpreterResult(InterpreterResult.Code.SUCCESS,
-            InterpreterResult.Type.TABLE, outputBuilder.toString());
+        return new InterpreterResult(
+            InterpreterResult.Code.SUCCESS, InterpreterResult.Type.TABLE, outputBuilder.toString());
       } else if (stmtInfo.output.data.imagePng != null) {
-        return new InterpreterResult(InterpreterResult.Code.SUCCESS,
-            InterpreterResult.Type.IMG, (String) stmtInfo.output.data.imagePng);
+        return new InterpreterResult(
+            InterpreterResult.Code.SUCCESS,
+            InterpreterResult.Type.IMG,
+            (String) stmtInfo.output.data.imagePng);
       } else if (result != null) {
         result = result.trim();
         if (result.startsWith("<link")
@@ -544,9 +571,15 @@ public abstract class BaseLivyInterpreter extends Interpreter {
       if (displayAppInfo) {
         InterpreterResult interpreterResult = new InterpreterResult(InterpreterResult.Code.SUCCESS);
         interpreterResult.add(result);
-        String appInfoHtml = "<hr/>Spark Application Id: " + sessionInfo.appId + "<br/>"
-            + "Spark WebUI: <a href=\"" + sessionInfo.webUIAddress + "\">"
-            + sessionInfo.webUIAddress + "</a>";
+        String appInfoHtml =
+            "<hr/>Spark Application Id: "
+                + sessionInfo.appId
+                + "<br/>"
+                + "Spark WebUI: <a href=\""
+                + sessionInfo.webUIAddress
+                + "\">"
+                + sessionInfo.webUIAddress
+                + "</a>";
         interpreterResult.add(InterpreterResult.Type.HTML, appInfoHtml);
         return interpreterResult;
       } else {
@@ -555,14 +588,13 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     }
   }
 
-  private StatementInfo executeStatement(ExecuteRequest executeRequest)
-      throws LivyException {
-    return StatementInfo.fromJson(callRestAPI("/sessions/" + sessionInfo.id + "/statements", "POST",
-        executeRequest.toJson()));
+  private StatementInfo executeStatement(ExecuteRequest executeRequest) throws LivyException {
+    return StatementInfo.fromJson(
+        callRestAPI(
+            "/sessions/" + sessionInfo.id + "/statements", "POST", executeRequest.toJson()));
   }
 
-  private StatementInfo getStatementInfo(int statementId)
-      throws LivyException {
+  private StatementInfo getStatementInfo(int statementId) throws LivyException {
     return StatementInfo.fromJson(
         callRestAPI("/sessions/" + sessionInfo.id + "/statements/" + statementId, "GET"));
   }
@@ -571,12 +603,11 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     callRestAPI("/sessions/" + sessionInfo.id + "/statements/" + statementId + "/cancel", "POST");
   }
 
-
   private RestTemplate createRestTemplate() {
     String keytabLocation = getProperty("zeppelin.livy.keytab");
     String principal = getProperty("zeppelin.livy.principal");
-    boolean isSpnegoEnabled = StringUtils.isNotEmpty(keytabLocation) &&
-        StringUtils.isNotEmpty(principal);
+    boolean isSpnegoEnabled =
+        StringUtils.isNotEmpty(keytabLocation) && StringUtils.isNotEmpty(principal);
 
     HttpClient httpClient = null;
     if (livyURL.startsWith("https:")) {
@@ -586,37 +617,37 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         throw new RuntimeException("No zeppelin.livy.ssl.trustStore specified for livy ssl");
       }
       if (StringUtils.isBlank(password)) {
-        throw new RuntimeException("No zeppelin.livy.ssl.trustStorePassword specified " +
-            "for livy ssl");
+        throw new RuntimeException(
+            "No zeppelin.livy.ssl.trustStorePassword specified " + "for livy ssl");
       }
       FileInputStream inputStream = null;
       try {
         inputStream = new FileInputStream(keystoreFile);
         KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
         trustStore.load(new FileInputStream(keystoreFile), password.toCharArray());
-        SSLContext sslContext = SSLContexts.custom()
-            .loadTrustMaterial(trustStore)
-            .build();
+        SSLContext sslContext = SSLContexts.custom().loadTrustMaterial(trustStore).build();
         SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext);
         HttpClientBuilder httpClientBuilder = HttpClients.custom().setSSLSocketFactory(csf);
-        RequestConfig reqConfig = new RequestConfig() {
-          @Override
-          public boolean isAuthenticationEnabled() {
-            return true;
-          }
-        };
+        RequestConfig reqConfig =
+            new RequestConfig() {
+              @Override
+              public boolean isAuthenticationEnabled() {
+                return true;
+              }
+            };
         httpClientBuilder.setDefaultRequestConfig(reqConfig);
-        Credentials credentials = new Credentials() {
-          @Override
-          public String getPassword() {
-            return null;
-          }
-
-          @Override
-          public Principal getUserPrincipal() {
-            return null;
-          }
-        };
+        Credentials credentials =
+            new Credentials() {
+              @Override
+              public String getPassword() {
+                return null;
+              }
+
+              @Override
+              public Principal getUserPrincipal() {
+                return null;
+              }
+            };
         CredentialsProvider credsProvider = new BasicCredentialsProvider();
         credsProvider.setCredentials(AuthScope.ANY, credentials);
         httpClientBuilder.setDefaultCredentialsProvider(credsProvider);
@@ -656,8 +687,9 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory(httpClient));
       }
     }
-    restTemplate.getMessageConverters().add(0,
-            new StringHttpMessageConverter(Charset.forName("UTF-8")));
+    restTemplate
+        .getMessageConverters()
+        .add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));
     return restTemplate;
   }
 
@@ -689,8 +721,10 @@ public abstract class BaseLivyInterpreter extends Interpreter {
       }
     } catch (HttpClientErrorException e) {
       response = new ResponseEntity(e.getResponseBodyAsString(), e.getStatusCode());
-      LOGGER.error(String.format("Error with %s StatusCode: %s",
-          response.getStatusCode().value(), e.getResponseBodyAsString()));
+      LOGGER.error(
+          String.format(
+              "Error with %s StatusCode: %s",
+              response.getStatusCode().value(), e.getResponseBodyAsString()));
     } catch (RestClientException e) {
       // Exception happens when kerberos is enabled.
       if (e.getCause() instanceof HttpClientErrorException) {
@@ -698,8 +732,10 @@ public abstract class BaseLivyInterpreter extends Interpreter {
         if (cause.getResponseBodyAsString().matches(SESSION_NOT_FOUND_PATTERN)) {
           throw new SessionNotFoundException(cause.getResponseBodyAsString());
         }
-        throw new LivyException(cause.getResponseBodyAsString() + "\n"
-            + ExceptionUtils.getFullStackTrace(ExceptionUtils.getRootCause(e)));
+        throw new LivyException(
+            cause.getResponseBodyAsString()
+                + "\n"
+                + ExceptionUtils.getFullStackTrace(ExceptionUtils.getRootCause(e)));
       }
       if (e instanceof HttpServerErrorException) {
         HttpServerErrorException errorException = (HttpServerErrorException) e;
@@ -714,25 +750,27 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     if (response == null) {
       throw new LivyException("No http response returned");
     }
-    LOGGER.debug("Get response, StatusCode: {}, responseBody: {}", response.getStatusCode(),
+    LOGGER.debug(
+        "Get response, StatusCode: {}, responseBody: {}",
+        response.getStatusCode(),
         response.getBody());
-    if (response.getStatusCode().value() == 200
-        || response.getStatusCode().value() == 201) {
+    if (response.getStatusCode().value() == 200 || response.getStatusCode().value() == 201) {
       return response.getBody();
     } else if (response.getStatusCode().value() == 404) {
       if (response.getBody().matches(SESSION_NOT_FOUND_PATTERN)) {
         throw new SessionNotFoundException(response.getBody());
       } else {
-        throw new APINotFoundException("No rest api found for " + targetURL +
-            ", " + response.getStatusCode());
+        throw new APINotFoundException(
+            "No rest api found for " + targetURL + ", " + response.getStatusCode());
       }
     } else {
       String responseString = response.getBody();
       if (responseString.contains("CreateInteractiveRequest[\\\"master\\\"]")) {
         return responseString;
       }
-      throw new LivyException(String.format("Error with %s StatusCode: %s",
-          response.getStatusCode().value(), responseString));
+      throw new LivyException(
+          String.format(
+              "Error with %s StatusCode: %s", response.getStatusCode().value(), responseString));
     }
   }
 
@@ -740,21 +778,23 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     try {
       callRestAPI("/sessions/" + sessionId, "DELETE");
     } catch (Exception e) {
-      LOGGER.error(String.format("Error closing session for user with session ID: %s",
-          sessionId), e);
+      LOGGER.error(
+          String.format("Error closing session for user with session ID: %s", sessionId), e);
     }
   }
 
   /*
-  * We create these POJO here to accommodate livy 0.3 which is not released yet. livy rest api has
-  * some changes from version to version. So we create these POJO in zeppelin side to accommodate
-  * incompatibility between versions. Later, when livy become more stable, we could just depend on
-  * livy client jar.
-  */
+   * We create these POJO here to accommodate livy 0.3 which is not released yet. livy rest api has
+   * some changes from version to version. So we create these POJO in zeppelin side to accommodate
+   * incompatibility between versions. Later, when livy become more stable, we could just depend on
+   * livy client jar.
+   */
   private static class CreateSessionRequest {
     public final String kind;
+
     @SerializedName("proxyUser")
     public final String user;
+
     public final Map<String, String> conf;
 
     CreateSessionRequest(String kind, String user, Map<String, String> conf) {
@@ -768,9 +808,7 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     }
   }
 
-  /**
-   *
-   */
+  /** */
   public static class SessionInfo {
 
     public final int id;
@@ -783,8 +821,15 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     public final Map<String, String> appInfo;
     public final List<String> log;
 
-    public SessionInfo(int id, String appId, String owner, String proxyUser, String state,
-                       String kind, Map<String, String> appInfo, List<String> log) {
+    public SessionInfo(
+        int id,
+        String appId,
+        String owner,
+        String proxyUser,
+        String state,
+        String kind,
+        Map<String, String> appInfo,
+        List<String> log) {
       this.id = id;
       this.appId = appId;
       this.owner = owner;
@@ -814,8 +859,7 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     public int size;
     public List<String> log;
 
-    SessionLog() {
-    }
+    SessionLog() {}
 
     public static SessionLog fromJson(String json) {
       return gson.fromJson(json, SessionLog.class);
@@ -842,8 +886,7 @@ public abstract class BaseLivyInterpreter extends Interpreter {
     public double progress;
     public StatementOutput output;
 
-    StatementInfo() {
-    }
+    StatementInfo() {}
 
     public static StatementInfo fromJson(String json) {
       String rightJson = "";
@@ -888,10 +931,13 @@ public abstract class BaseLivyInterpreter extends Interpreter {
       private static class Data {
         @SerializedName("text/plain")
         public String plainText;
+
         @SerializedName("image/png")
         public String imagePng;
+
         @SerializedName("application/json")
         public String applicationJson;
+
         @SerializedName("application/vnd.livy.table.v1+json")
         public TableMagic applicationLivyTableJson;
       }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivyException.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivyException.java b/livy/src/main/java/org/apache/zeppelin/livy/LivyException.java
index c14351f..4039004 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivyException.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivyException.java
@@ -19,12 +19,9 @@ package org.apache.zeppelin.livy;
 
 import org.apache.zeppelin.interpreter.InterpreterException;
 
-/**
- * Livy api related exception.
- */
+/** Livy api related exception. */
 public class LivyException extends InterpreterException {
-  public LivyException() {
-  }
+  public LivyException() {}
 
   public LivyException(String message) {
     super(message);
@@ -38,8 +35,8 @@ public class LivyException extends InterpreterException {
     super(cause);
   }
 
-  public LivyException(String message, Throwable cause, boolean enableSuppression,
-                       boolean writableStackTrace) {
+  public LivyException(
+      String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
     super(message, cause, enableSuppression, writableStackTrace);
   }
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivyPySpark3Interpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySpark3Interpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySpark3Interpreter.java
index 174c2c0..d074e32 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySpark3Interpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySpark3Interpreter.java
@@ -19,10 +19,7 @@ package org.apache.zeppelin.livy;
 
 import java.util.Properties;
 
-
-/**
- * Livy PySpark interpreter for Zeppelin.
- */
+/** Livy PySpark interpreter for Zeppelin. */
 public class LivyPySpark3Interpreter extends LivyPySparkBaseInterpreter {
 
   public LivyPySpark3Interpreter(Properties property) {
@@ -33,5 +30,4 @@ public class LivyPySpark3Interpreter extends LivyPySparkBaseInterpreter {
   public String getSessionKind() {
     return "pyspark3";
   }
-
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkBaseInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkBaseInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkBaseInterpreter.java
index 32399c6..c5729d1 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkBaseInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkBaseInterpreter.java
@@ -19,9 +19,7 @@ package org.apache.zeppelin.livy;
 
 import java.util.Properties;
 
-/**
- * Base class for PySpark Interpreter.
- */
+/** Base class for PySpark Interpreter. */
 public abstract class LivyPySparkBaseInterpreter extends BaseLivyInterpreter {
 
   public LivyPySparkBaseInterpreter(Properties property) {
@@ -31,22 +29,21 @@ public abstract class LivyPySparkBaseInterpreter extends BaseLivyInterpreter {
   @Override
   protected String extractAppId() throws LivyException {
     return extractStatementResult(
-        interpret("sc.applicationId", null, false, false, false).message()
-            .get(0).getData());
+        interpret("sc.applicationId", null, false, false, false).message().get(0).getData());
   }
 
   @Override
   protected String extractWebUIAddress() throws LivyException {
     return extractStatementResult(
-        interpret(
-            "sc._jsc.sc().ui().get().appUIAddress()", null, false, false, false)
-            .message().get(0).getData());
+        interpret("sc._jsc.sc().ui().get().appUIAddress()", null, false, false, false)
+            .message()
+            .get(0)
+            .getData());
   }
 
   /**
-   * Extract the eval result of spark shell, e.g. extract application_1473129941656_0048
-   * from following:
-   * u'application_1473129941656_0048'
+   * Extract the eval result of spark shell, e.g. extract application_1473129941656_0048 from
+   * following: u'application_1473129941656_0048'
    *
    * @param result
    * @return
@@ -56,8 +53,8 @@ public abstract class LivyPySparkBaseInterpreter extends BaseLivyInterpreter {
     if ((pos = result.indexOf("'")) >= 0) {
       return result.substring(pos + 1, result.length() - 1).trim();
     } else {
-      throw new RuntimeException("No result can be extracted from '" + result + "', " +
-          "something must be wrong");
+      throw new RuntimeException(
+          "No result can be extracted from '" + result + "', " + "something must be wrong");
     }
   }
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkInterpreter.java
index d664bbe..9b15274 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivyPySparkInterpreter.java
@@ -19,10 +19,7 @@ package org.apache.zeppelin.livy;
 
 import java.util.Properties;
 
-
-/**
- * Livy PySpark interpreter for Zeppelin.
- */
+/** Livy PySpark interpreter for Zeppelin. */
 public class LivyPySparkInterpreter extends LivyPySparkBaseInterpreter {
 
   public LivyPySparkInterpreter(Properties property) {
@@ -33,6 +30,4 @@ public class LivyPySparkInterpreter extends LivyPySparkBaseInterpreter {
   public String getSessionKind() {
     return "pyspark";
   }
-
-
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivySharedInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivySharedInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivySharedInterpreter.java
index c912dc9..df0fd07 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivySharedInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivySharedInterpreter.java
@@ -17,20 +17,16 @@
 
 package org.apache.zeppelin.livy;
 
-import org.apache.commons.lang.StringUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.Properties;
-
+import org.apache.commons.lang.StringUtils;
 import org.apache.zeppelin.interpreter.InterpreterContext;
 import org.apache.zeppelin.interpreter.InterpreterException;
 import org.apache.zeppelin.interpreter.InterpreterResult;
 import org.apache.zeppelin.interpreter.InterpreterUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-/**
- * Livy Interpreter for shared kind which share SparkContext across spark/pyspark/r.
- */
+/** Livy Interpreter for shared kind which share SparkContext across spark/pyspark/r. */
 public class LivySharedInterpreter extends BaseLivyInterpreter {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(LivySharedInterpreter.class);
@@ -63,8 +59,8 @@ public class LivySharedInterpreter extends BaseLivyInterpreter {
         isSupported = false;
       }
     } catch (LivyException e) {
-      String msg = "Fail to create session, please check livy interpreter log and " +
-          "livy server log";
+      String msg =
+          "Fail to create session, please check livy interpreter log and " + "livy server log";
       throw new InterpreterException(msg, e);
     }
   }
@@ -82,8 +78,8 @@ public class LivySharedInterpreter extends BaseLivyInterpreter {
       return interpret(st, codeType, context.getParagraphId(), this.displayAppInfo, true, true);
     } catch (LivyException e) {
       LOGGER.error("Fail to interpret:" + st, e);
-      return new InterpreterResult(InterpreterResult.Code.ERROR,
-          InterpreterUtils.getMostRelevantMessage(e));
+      return new InterpreterResult(
+          InterpreterResult.Code.ERROR, InterpreterUtils.getMostRelevantMessage(e));
     }
   }
 

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivySparkInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkInterpreter.java
index ad62e9b..e7b3570 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkInterpreter.java
@@ -19,9 +19,7 @@ package org.apache.zeppelin.livy;
 
 import java.util.Properties;
 
-/**
- * Livy Spark interpreter for Zeppelin.
- */
+/** Livy Spark interpreter for Zeppelin. */
 public class LivySparkInterpreter extends BaseLivyInterpreter {
 
   public LivySparkInterpreter(Properties property) {
@@ -36,8 +34,7 @@ public class LivySparkInterpreter extends BaseLivyInterpreter {
   @Override
   protected String extractAppId() throws LivyException {
     return extractStatementResult(
-        interpret("sc.applicationId", null, false, false, false).message()
-            .get(0).getData());
+        interpret("sc.applicationId", null, false, false, false).message().get(0).getData());
   }
 
   @Override
@@ -45,17 +42,25 @@ public class LivySparkInterpreter extends BaseLivyInterpreter {
     interpret(
         "val webui=sc.getClass.getMethod(\"ui\").invoke(sc).asInstanceOf[Some[_]].get",
         null,
-        null, false, false, false);
+        null,
+        false,
+        false,
+        false);
     return extractStatementResult(
         interpret(
-            "webui.getClass.getMethod(\"appUIAddress\").invoke(webui)", null, false, false, false)
-            .message().get(0).getData());
+                "webui.getClass.getMethod(\"appUIAddress\").invoke(webui)",
+                null,
+                false,
+                false,
+                false)
+            .message()
+            .get(0)
+            .getData());
   }
 
   /**
-   * Extract the eval result of spark shell, e.g. extract application_1473129941656_0048
-   * from following:
-   * res0: String = application_1473129941656_0048
+   * Extract the eval result of spark shell, e.g. extract application_1473129941656_0048 from
+   * following: res0: String = application_1473129941656_0048
    *
    * @param result
    * @return
@@ -65,8 +70,8 @@ public class LivySparkInterpreter extends BaseLivyInterpreter {
     if ((pos = result.indexOf("=")) >= 0) {
       return result.substring(pos + 1).trim();
     } else {
-      throw new RuntimeException("No result can be extracted from '" + result + "', " +
-          "something must be wrong");
+      throw new RuntimeException(
+          "No result can be extracted from '" + result + "', " + "something must be wrong");
     }
   }
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivySparkRInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkRInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkRInterpreter.java
index c270437..6aab4f0 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkRInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkRInterpreter.java
@@ -19,10 +19,7 @@ package org.apache.zeppelin.livy;
 
 import java.util.Properties;
 
-
-/**
- * Livy PySpark interpreter for Zeppelin.
- */
+/** Livy PySpark interpreter for Zeppelin. */
 public class LivySparkRInterpreter extends BaseLivyInterpreter {
 
   public LivySparkRInterpreter(Properties property) {
@@ -36,13 +33,13 @@ public class LivySparkRInterpreter extends BaseLivyInterpreter {
 
   @Override
   protected String extractAppId() throws LivyException {
-    //TODO(zjffdu) depends on SparkR
+    // TODO(zjffdu) depends on SparkR
     return null;
   }
 
   @Override
   protected String extractWebUIAddress() throws LivyException {
-    //TODO(zjffdu) depends on SparkR
+    // TODO(zjffdu) depends on SparkR
     return null;
   }
 }

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivySparkSQLInterpreter.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkSQLInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkSQLInterpreter.java
index b2e18f3..12c641a 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivySparkSQLInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivySparkSQLInterpreter.java
@@ -17,6 +17,11 @@
 
 package org.apache.zeppelin.livy;
 
+import static org.apache.commons.lang.StringEscapeUtils.escapeJavaScript;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
 import org.apache.commons.lang.StringUtils;
 import org.apache.zeppelin.interpreter.InterpreterContext;
 import org.apache.zeppelin.interpreter.InterpreterException;
@@ -28,15 +33,7 @@ import org.apache.zeppelin.interpreter.ResultMessages;
 import org.apache.zeppelin.scheduler.Scheduler;
 import org.apache.zeppelin.scheduler.SchedulerFactory;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Properties;
-
-import static org.apache.commons.lang.StringEscapeUtils.escapeJavaScript;
-
-/**
- * Livy SparkSQL Interpreter for Zeppelin.
- */
+/** Livy SparkSQL Interpreter for Zeppelin. */
 public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
   public static final String ZEPPELIN_LIVY_SPARK_SQL_FIELD_TRUNCATE =
       "zeppelin.livy.spark.sql.field.truncate";
@@ -71,13 +68,13 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
     // As we don't know whether livyserver use spark2 or spark1, so we will detect SparkSession
     // to judge whether it is using spark2.
     try {
-      InterpreterContext context = InterpreterContext.builder()
-          .setInterpreterOut(new InterpreterOutput(null))
-          .build();
+      InterpreterContext context =
+          InterpreterContext.builder().setInterpreterOut(new InterpreterOutput(null)).build();
       InterpreterResult result = sparkInterpreter.interpret("spark", context);
-      if (result.code() == InterpreterResult.Code.SUCCESS &&
-          result.message().get(0).getData().contains("org.apache.spark.sql.SparkSession")) {
-        LOGGER.info("SparkSession is detected so we are using spark 2.x for session {}",
+      if (result.code() == InterpreterResult.Code.SUCCESS
+          && result.message().get(0).getData().contains("org.apache.spark.sql.SparkSession")) {
+        LOGGER.info(
+            "SparkSession is detected so we are using spark 2.x for session {}",
             sparkInterpreter.getSessionInfo().id);
         isSpark2 = true;
       } else {
@@ -89,12 +86,14 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
           // create SqlContext if it is not available, as in livy 0.2 sqlContext
           // is not available.
           LOGGER.info("sqlContext is not detected, try to create SQLContext by ourselves");
-          result = sparkInterpreter.interpret(
-              "val sqlContext = new org.apache.spark.sql.SQLContext(sc)\n"
-                  + "import sqlContext.implicits._", context);
+          result =
+              sparkInterpreter.interpret(
+                  "val sqlContext = new org.apache.spark.sql.SQLContext(sc)\n"
+                      + "import sqlContext.implicits._",
+                  context);
           if (result.code() == InterpreterResult.Code.ERROR) {
-            throw new LivyException("Fail to create SQLContext," +
-                result.message().get(0).getData());
+            throw new LivyException(
+                "Fail to create SQLContext," + result.message().get(0).getData());
           }
         }
       }
@@ -113,11 +112,10 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
       // use triple quote so that we don't need to do string escape.
       String sqlQuery = null;
       if (isSpark2) {
-        sqlQuery = "spark.sql(\"\"\"" + line + "\"\"\").show(" + maxResult + ", " +
-            truncate + ")";
+        sqlQuery = "spark.sql(\"\"\"" + line + "\"\"\").show(" + maxResult + ", " + truncate + ")";
       } else {
-        sqlQuery = "sqlContext.sql(\"\"\"" + line + "\"\"\").show(" + maxResult + ", " +
-            truncate + ")";
+        sqlQuery =
+            "sqlContext.sql(\"\"\"" + line + "\"\"\").show(" + maxResult + ", " + truncate + ")";
       }
       InterpreterResult result = sparkInterpreter.interpret(sqlQuery, context);
       if (result.code() == InterpreterResult.Code.SUCCESS) {
@@ -130,8 +128,9 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
             List<String> rows = parseSQLOutput(message.getData());
             result2.add(InterpreterResult.Type.TABLE, StringUtils.join(rows, "\n"));
             if (rows.size() >= (maxResult + 1)) {
-              result2.add(ResultMessages.getExceedsLimitRowsMessage(maxResult,
-                  ZEPPELIN_LIVY_SPARK_SQL_MAX_RESULT));
+              result2.add(
+                  ResultMessages.getExceedsLimitRowsMessage(
+                      maxResult, ZEPPELIN_LIVY_SPARK_SQL_MAX_RESULT));
             }
           } else {
             result2.add(message.getType(), message.getData());
@@ -143,8 +142,8 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
       }
     } catch (Exception e) {
       LOGGER.error("Exception in LivySparkSQLInterpreter while interpret ", e);
-      return new InterpreterResult(InterpreterResult.Code.ERROR,
-          InterpreterUtils.getMostRelevantMessage(e));
+      return new InterpreterResult(
+          InterpreterResult.Code.ERROR, InterpreterUtils.getMostRelevantMessage(e));
     }
   }
 
@@ -202,9 +201,7 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
     return rows;
   }
 
-  /**
-   * Represent the start and end index of each cell.
-   */
+  /** Represent the start and end index of each cell. */
   private static class Pair {
     private int start;
     private int end;
@@ -223,8 +220,9 @@ public class LivySparkSQLInterpreter extends BaseLivyInterpreter {
   public Scheduler getScheduler() {
     if (concurrentSQL()) {
       int maxConcurrency = 10;
-      return SchedulerFactory.singleton().createOrGetParallelScheduler(
-          LivySparkInterpreter.class.getName() + this.hashCode(), maxConcurrency);
+      return SchedulerFactory.singleton()
+          .createOrGetParallelScheduler(
+              LivySparkInterpreter.class.getName() + this.hashCode(), maxConcurrency);
     } else {
       if (sparkInterpreter != null) {
         return sparkInterpreter.getScheduler();

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/LivyVersion.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/LivyVersion.java b/livy/src/main/java/org/apache/zeppelin/livy/LivyVersion.java
index 55ebd57..1d56e83 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/LivyVersion.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/LivyVersion.java
@@ -20,9 +20,7 @@ package org.apache.zeppelin.livy;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-/**
- * Provide reading comparing capability of livy version.
- */
+/** Provide reading comparing capability of livy version. */
 public class LivyVersion {
   private static final Logger logger = LoggerFactory.getLogger(LivyVersion.class);
 
@@ -52,8 +50,8 @@ public class LivyVersion {
       // version is always 5 digits. (e.g. 2.0.0 -> 20000, 1.6.2 -> 10602)
       version = Integer.parseInt(String.format("%d%02d%02d", major, minor, patch));
     } catch (Exception e) {
-      logger.error("Can not recognize Livy version " + versionString +
-          ". Assume it's a future release", e);
+      logger.error(
+          "Can not recognize Livy version " + versionString + ". Assume it's a future release", e);
 
       // assume it is future release
       version = 99999;

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/SessionDeadException.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/SessionDeadException.java b/livy/src/main/java/org/apache/zeppelin/livy/SessionDeadException.java
index 5811790..dfbb56e 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/SessionDeadException.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/SessionDeadException.java
@@ -17,6 +17,4 @@
 
 package org.apache.zeppelin.livy;
 
-public class SessionDeadException extends LivyException {
-
-}
+public class SessionDeadException extends LivyException {}

http://git-wip-us.apache.org/repos/asf/zeppelin/blob/55f6c91c/livy/src/main/java/org/apache/zeppelin/livy/SessionNotFoundException.java
----------------------------------------------------------------------
diff --git a/livy/src/main/java/org/apache/zeppelin/livy/SessionNotFoundException.java b/livy/src/main/java/org/apache/zeppelin/livy/SessionNotFoundException.java
index 4547057..3f56116 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/SessionNotFoundException.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/SessionNotFoundException.java
@@ -17,9 +17,7 @@
 
 package org.apache.zeppelin.livy;
 
-/**
- *
- */
+/** */
 public class SessionNotFoundException extends LivyException {
 
   public SessionNotFoundException(String message) {