ZEPPELIN-3141. Fixed Checkstyle errors and warnings in the pig module

pig/pom.xml

@@ -190,6 +190,13 @@
                     <forkMode>always</forkMode>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <configuration>
+                    <skip>false</skip>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 </project>

pig/src/main/java/org/apache/zeppelin/pig/BasePigInterpreter.java

@@ -23,10 +23,6 @@
 import org.apache.pig.backend.BackendException;
 import org.apache.pig.backend.hadoop.executionengine.HExecutionEngine;
 import org.apache.pig.backend.hadoop.executionengine.Launcher;
-import org.apache.zeppelin.interpreter.Interpreter;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.scheduler.Scheduler;
-import org.apache.zeppelin.scheduler.SchedulerFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -35,12 +31,16 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.apache.zeppelin.interpreter.Interpreter;
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.scheduler.Scheduler;
+import org.apache.zeppelin.scheduler.SchedulerFactory;
+
 /**
  *
  */
 public abstract class BasePigInterpreter extends Interpreter {
-
-  private static Logger LOGGER = LoggerFactory.getLogger(BasePigInterpreter.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(BasePigInterpreter.class);
 
   protected ConcurrentHashMap<String, PigScriptListener> listenerMap = new ConcurrentHashMap<>();
 

pig/src/main/java/org/apache/zeppelin/pig/PigInterpreter.java

@@ -22,23 +22,26 @@
 import org.apache.pig.PigServer;
 import org.apache.pig.impl.logicalLayer.FrontendException;
 import org.apache.pig.tools.pigscript.parser.ParseException;
-import org.apache.pig.tools.pigstats.*;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.interpreter.InterpreterResult;
-import org.apache.zeppelin.interpreter.InterpreterResult.Code;
+import org.apache.pig.tools.pigstats.PigStats;
+import org.apache.pig.tools.pigstats.ScriptState;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.IOException;
 import java.io.PrintStream;
-import java.util.*;
+import java.util.Map;
+import java.util.Properties;
+
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.interpreter.InterpreterResult;
+import org.apache.zeppelin.interpreter.InterpreterResult.Code;
 
 /**
  * Pig interpreter for Zeppelin.
  */
 public class PigInterpreter extends BasePigInterpreter {
-  private static Logger LOGGER = LoggerFactory.getLogger(PigInterpreter.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(PigInterpreter.class);
 
   private PigServer pigServer;
   private boolean includeJobStats = false;

pig/src/main/java/org/apache/zeppelin/pig/PigQueryInterpreter.java

@@ -15,10 +15,8 @@
  * limitations under the License.
  */
 
-
 package org.apache.zeppelin.pig;
 
-
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.exception.ExceptionUtils;
 import org.apache.pig.PigServer;
@@ -28,8 +26,6 @@
 import org.apache.pig.tools.pigscript.parser.ParseException;
 import org.apache.pig.tools.pigstats.PigStats;
 import org.apache.pig.tools.pigstats.ScriptState;
-import org.apache.zeppelin.interpreter.*;
-import org.apache.zeppelin.interpreter.InterpreterResult.Code;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -40,12 +36,20 @@
 import java.util.List;
 import java.util.Properties;
 
+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.InterpreterResult.Code;
+import org.apache.zeppelin.interpreter.LazyOpenInterpreter;
+import org.apache.zeppelin.interpreter.ResultMessages;
+import org.apache.zeppelin.interpreter.WrappedInterpreter;
+
 /**
  *
  */
 public class PigQueryInterpreter extends BasePigInterpreter {
-
-  private static Logger LOGGER = LoggerFactory.getLogger(PigQueryInterpreter.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(PigQueryInterpreter.class);
   private static final String MAX_RESULTS = "zeppelin.pig.maxResult";
   private PigServer pigServer;
   private int maxResult;

pig/src/main/java/org/apache/zeppelin/pig/PigScriptListener.java

@@ -15,7 +15,6 @@
  * limitations under the License.
  */
 
-
 package org.apache.zeppelin.pig;
 
 import org.apache.pig.impl.plan.OperatorPlan;
@@ -32,8 +31,7 @@
  *
  */
 public class PigScriptListener implements PigProgressNotificationListener {
-
-  private static Logger LOGGER = LoggerFactory.getLogger(PigScriptListener.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(PigScriptListener.class);
 
   private Set<String> jobIds = new HashSet();
   private int progress;

pig/src/main/java/org/apache/zeppelin/pig/PigUtils.java

@@ -17,40 +17,21 @@
 
 package org.apache.zeppelin.pig;
 
-
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
-import org.apache.commons.lang.exception.ExceptionUtils;
-import org.apache.pig.PigRunner;
-import org.apache.pig.backend.hadoop.executionengine.spark.plan.SparkOperator;
-import org.apache.pig.backend.hadoop.executionengine.tez.TezExecType;
-import org.apache.pig.tools.pigstats.InputStats;
-import org.apache.pig.tools.pigstats.JobStats;
-import org.apache.pig.tools.pigstats.OutputStats;
-import org.apache.pig.tools.pigstats.PigStats;
-import org.apache.pig.tools.pigstats.mapreduce.MRJobStats;
-import org.apache.pig.tools.pigstats.mapreduce.SimplePigStats;
-import org.apache.pig.tools.pigstats.spark.SparkJobStats;
-import org.apache.pig.tools.pigstats.spark.SparkPigStats;
-import org.apache.pig.tools.pigstats.spark.SparkScriptState;
-import org.apache.pig.tools.pigstats.tez.TezDAGStats;
-import org.apache.pig.tools.pigstats.tez.TezPigScriptStats;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
-import java.lang.reflect.Field;
-import java.text.SimpleDateFormat;
-import java.util.*;
+import java.util.List;
 
 /**
  *
  */
 public class PigUtils {
-
-  private static Logger LOGGER = LoggerFactory.getLogger(PigUtils.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(PigUtils.class);
 
   protected static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
 
@@ -66,5 +47,4 @@ public static File createTempPigScript(String content) throws IOException {
   public static File createTempPigScript(List<String> lines) throws IOException {
     return createTempPigScript(StringUtils.join(lines, "\n"));
   }
-
 }

pig/src/test/java/org/apache/zeppelin/pig/PigInterpreterSparkTest.java

@@ -16,12 +16,12 @@
  * limitations under the License.
  */
 
-
 package org.apache.zeppelin.pig;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 import org.apache.commons.io.IOUtils;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.interpreter.InterpreterResult;
 import org.junit.After;
 import org.junit.Test;
 
@@ -30,9 +30,8 @@
 import java.io.IOException;
 import java.util.Properties;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.interpreter.InterpreterResult;
 
 public class PigInterpreterSparkTest {
   private PigInterpreter pigInterpreter;
@@ -86,7 +85,8 @@ public void testBasics() throws IOException {
     result = pigInterpreter.interpret(pigscript, context);
     assertEquals(InterpreterResult.Type.TEXT, result.message().get(0).getType());
     assertEquals(InterpreterResult.Code.ERROR, result.code());
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // syntax error
     pigscript = "a = load '" + tmpFile.getAbsolutePath() + "';"
@@ -133,7 +133,8 @@ public void testIncludeJobStats() throws IOException {
     assertEquals(InterpreterResult.Type.TEXT, result.message().get(0).getType());
     assertEquals(InterpreterResult.Code.ERROR, result.code());
     // no job is launched, so no jobStats
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // execution error
     pigscript = "a = load 'invalid_path';"

pig/src/test/java/org/apache/zeppelin/pig/PigInterpreterTest.java

@@ -16,25 +16,24 @@
  * limitations under the License.
  */
 
-
 package org.apache.zeppelin.pig;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 import org.apache.commons.io.IOUtils;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.interpreter.InterpreterResult;
-import org.apache.zeppelin.interpreter.InterpreterResult.Code;
-import org.apache.zeppelin.interpreter.InterpreterResult.Type;
 import org.junit.After;
-import org.junit.Before;
 import org.junit.Test;
 
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.util.Properties;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.interpreter.InterpreterResult;
+import org.apache.zeppelin.interpreter.InterpreterResult.Code;
+import org.apache.zeppelin.interpreter.InterpreterResult.Type;
 
 public class PigInterpreterTest {
 
@@ -48,7 +47,7 @@ private void setUpLocal(boolean includeJobStats) {
     pigInterpreter = new PigInterpreter(properties);
     pigInterpreter.open();
     context = new InterpreterContext(null, "paragraph_id", null, null, null,
-        null, null, null, null, null, null,null, null);
+        null, null, null, null, null, null, null, null);
   }
 
   @After
@@ -89,7 +88,8 @@ public void testBasics() throws IOException {
     result = pigInterpreter.interpret(pigscript, context);
     assertEquals(Type.TEXT, result.message().get(0).getType());
     assertEquals(Code.ERROR, result.code());
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // execution error
     pigscript = "a = load 'invalid_path';"
@@ -139,7 +139,8 @@ public void testIncludeJobStats() throws IOException {
     assertEquals(Code.ERROR, result.code());
     // no job is launched, so no jobStats
     assertTrue(!result.message().get(0).getData().contains("Counters:"));
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // execution error
     pigscript = "a = load 'invalid_path';"

pig/src/test/java/org/apache/zeppelin/pig/PigInterpreterTezTest.java

@@ -16,25 +16,24 @@
  * limitations under the License.
  */
 
-
 package org.apache.zeppelin.pig;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 import org.apache.commons.io.IOUtils;
-import org.apache.zeppelin.interpreter.InterpreterContext;
-import org.apache.zeppelin.interpreter.InterpreterResult;
-import org.apache.zeppelin.interpreter.InterpreterResult.Code;
-import org.apache.zeppelin.interpreter.InterpreterResult.Type;
 import org.junit.After;
-import org.junit.Before;
 import org.junit.Test;
 
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.util.Properties;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import org.apache.zeppelin.interpreter.InterpreterContext;
+import org.apache.zeppelin.interpreter.InterpreterResult;
+import org.apache.zeppelin.interpreter.InterpreterResult.Code;
+import org.apache.zeppelin.interpreter.InterpreterResult.Type;
 
 public class PigInterpreterTezTest {
 
@@ -94,7 +93,8 @@ public void testBasics() throws IOException {
     result = pigInterpreter.interpret(pigscript, context);
     assertEquals(Type.TEXT, result.message().get(0).getType());
     assertEquals(Code.ERROR, result.code());
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // syntax error
     pigscript = "a = load '" + tmpFile.getAbsolutePath() + "';"
@@ -143,7 +143,8 @@ public void testIncludeJobStats() throws IOException {
     assertEquals(Code.ERROR, result.code());
     // no job is launched, so no jobStats
     assertTrue(!result.message().get(0).getData().contains("Vertex Stats"));
-    assertTrue(result.message().get(0).getData().contains("Syntax error, unexpected symbol at or near 'a'"));
+    assertTrue(result.message().get(0).getData().contains(
+            "Syntax error, unexpected symbol at or near 'a'"));
 
     // execution error
     pigscript = "a = load 'invalid_path';"