HBASE-19482 Fixed remaining Checkstyle errors in hbase-spark-it and enabled Checkstyle to fail on violations

hbase-spark-it/pom.xml

@@ -178,7 +178,22 @@
           </execution>
         </executions>
       </plugin>
-
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>checkstyle</id>
+            <phase>validate</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+            <configuration>
+              <failOnViolation>true</failOnViolation>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 

hbase-spark-it/src/test/java/org/apache/hadoop/hbase/spark/IntegrationTestSparkBulkLoad.java

@@ -19,6 +19,18 @@
 package org.apache.hadoop.hbase.spark;
 
 import com.google.common.collect.Sets;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.commons.logging.Log;
@@ -35,7 +47,6 @@ import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.IntegrationTestBase;
 import org.apache.hadoop.hbase.IntegrationTestingUtility;
 import org.apache.hadoop.hbase.TableName;
-
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -44,41 +55,29 @@ import org.apache.hadoop.hbase.client.RegionLocator;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Table;
-
 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
-
 import org.apache.hadoop.hbase.mapreduce.IntegrationTestBulkLoad;
 import org.apache.hadoop.hbase.tool.LoadIncrementalHFiles;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.hbase.util.RegionSplitter;
-
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.util.ToolRunner;
+
+import org.apache.spark.Partitioner;
 import org.apache.spark.SerializableWritable;
 import org.apache.spark.SparkConf;
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
-
-import org.apache.spark.Partitioner;
-
 import org.apache.spark.api.java.function.Function;
 import org.apache.spark.api.java.function.Function2;
 import org.apache.spark.api.java.function.PairFlatMapFunction;
 import org.apache.spark.api.java.function.VoidFunction;
+
 import org.junit.Test;
+
 import scala.Tuple2;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.Random;
-import java.util.Set;
 
 /**
  * Test Bulk Load and Spark on a distributed cluster.
@@ -89,7 +88,8 @@ import java.util.Set;
  *   First add hbase related jars and hbase-spark.jar into spark classpath.
  *
  *   spark-submit --class org.apache.hadoop.hbase.spark.IntegrationTestSparkBulkLoad
- *                HBASE_HOME/lib/hbase-spark-it-XXX-tests.jar -m slowDeterministic -Dhbase.spark.bulkload.chainlength=300
+ *                HBASE_HOME/lib/hbase-spark-it-XXX-tests.jar -m slowDeterministic
+ *                -Dhbase.spark.bulkload.chainlength=300
  */
 public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
 
@@ -140,7 +140,7 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   /**
    * Running spark job to create LinkedList for testing
    * @param iteration iteration th of this job
-   * @throws Exception
+   * @throws Exception if an HBase operation or getting the test directory fails
    */
   public void runLinkedListSparkJob(int iteration) throws Exception {
     String jobName =  IntegrationTestSparkBulkLoad.class.getSimpleName() + " _load " +
@@ -168,7 +168,8 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
     LOG.info("Partition RDD into " + partitionNum + " parts");
     List<String> temp = new ArrayList<>();
     JavaRDD<List<byte[]>> rdd = jsc.parallelize(temp, partitionNum).
-        mapPartitionsWithIndex(new LinkedListCreationMapper(new SerializableWritable<>(hbaseConf)), false);
+        mapPartitionsWithIndex(new LinkedListCreationMapper(new SerializableWritable<>(hbaseConf)),
+                false);
 
     hbaseContext.bulkLoad(rdd, getTablename(), new ListToKeyValueFunc(), output.toUri().getPath(),
         new HashMap<>(), false, HConstants.DEFAULT_MAX_FILE_SIZE);
@@ -267,14 +268,12 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   }
 
   /**
-   * After adding data to the table start a mr job to
+   * After adding data to the table start a mr job to check the bulk load.
-   * @throws IOException
-   * @throws ClassNotFoundException
-   * @throws InterruptedException
    */
   public void runCheck() throws Exception {
     LOG.info("Running check");
-    String jobName = IntegrationTestSparkBulkLoad.class.getSimpleName() + "_check" + EnvironmentEdgeManager.currentTime();
+    String jobName = IntegrationTestSparkBulkLoad.class.getSimpleName() + "_check" +
+            EnvironmentEdgeManager.currentTime();
 
     SparkConf sparkConf = new SparkConf().setAppName(jobName).setMaster("local");
     Configuration hbaseConf = new Configuration(getConf());
@@ -318,14 +317,15 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   }
 
   /**
-   * PairFlatMapFunction used to transfer <Row, Result> to Tuple <SparkLinkKey, SparkLinkChain>
+   * PairFlatMapFunction used to transfer {@code <Row, Result>} to
+   * {@code Tuple<SparkLinkKey, SparkLinkChain>}.
    */
   public static class LinkedListCheckingFlatMapFunc implements
       PairFlatMapFunction<Tuple2<ImmutableBytesWritable, Result>, SparkLinkKey, SparkLinkChain> {
 
     @Override
-    public Iterable<Tuple2<SparkLinkKey, SparkLinkChain>> call(Tuple2<ImmutableBytesWritable, Result> v)
+    public Iterable<Tuple2<SparkLinkKey, SparkLinkChain>> call(Tuple2<ImmutableBytesWritable,
-        throws Exception {
+            Result> v) throws Exception {
       Result value = v._2();
       long longRk = Bytes.toLong(value.getRow());
       List<Tuple2<SparkLinkKey, SparkLinkChain>> list = new LinkedList<>();
@@ -357,8 +357,10 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
       Function2<List<SparkLinkChain>, SparkLinkChain, List<SparkLinkChain>> {
     @Override
     public List<SparkLinkChain> call(List<SparkLinkChain> v1, SparkLinkChain v2) throws Exception {
-      if (v1 == null)
+      if (v1 == null) {
         v1 = new LinkedList<>();
+      }
+
       v1.add(v2);
       return v1;
     }
@@ -367,7 +369,8 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   public static class mergeCombinersFunc implements
       Function2<List<SparkLinkChain>, List<SparkLinkChain>, List<SparkLinkChain>> {
     @Override
-    public List<SparkLinkChain> call(List<SparkLinkChain> v1, List<SparkLinkChain> v2) throws Exception {
+    public List<SparkLinkChain> call(List<SparkLinkChain> v1, List<SparkLinkChain> v2)
+            throws Exception {
       v1.addAll(v2);
       return v1;
     }
@@ -393,8 +396,10 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
 
     @Override
     public int getPartition(Object key) {
-      if (!(key instanceof SparkLinkKey))
+      if (!(key instanceof SparkLinkKey)) {
         return -1;
+      }
+
       int hash = ((SparkLinkKey) key).getChainId().hashCode();
       return Math.abs(hash % numPartions);
 
@@ -402,7 +407,7 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   }
 
   /**
-   * Sort all LinkChain for one LinkKey, and test List<LinkChain>
+   * Sort all LinkChain for one LinkKey, and test {@code List<LinkChain>}.
    */
   public static class LinkedListCheckingForeachFunc
       implements VoidFunction<Tuple2<SparkLinkKey, List<SparkLinkChain>>> {
@@ -483,8 +488,10 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
 
     @Override
     public boolean equals(Object other) {
-      if (!(other instanceof SparkLinkKey))
+      if (!(other instanceof SparkLinkKey)) {
         return false;
+      }
+
       SparkLinkKey otherKey = (SparkLinkKey) other;
       return this.getChainId().equals(otherKey.getChainId());
     }
@@ -492,8 +499,11 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
     @Override
     public int compareTo(SparkLinkKey other) {
       int res = getChainId().compareTo(other.getChainId());
-      if (res == 0)
+
+      if (res == 0) {
         res = getOrder().compareTo(other.getOrder());
+      }
+
       return res;
     }
   }
@@ -536,8 +546,10 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
 
     @Override
     public boolean equals(Object other) {
-      if (!(other instanceof SparkLinkChain))
+      if (!(other instanceof SparkLinkChain)) {
         return false;
+      }
+
       SparkLinkChain otherKey = (SparkLinkChain) other;
       return this.getRk().equals(otherKey.getRk()) && this.getNext().equals(otherKey.getNext());
     }
@@ -547,12 +559,15 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
   /**
    * Allow the scan to go to replica, this would not affect the runCheck()
    * Since data are BulkLoaded from HFile into table
-   * @throws IOException
+   * @throws IOException if an HBase operation fails
-   * @throws InterruptedException
+   * @throws InterruptedException if modifying the table fails
    */
   private void installSlowingCoproc() throws IOException, InterruptedException {
     int replicaCount = conf.getInt(NUM_REPLICA_COUNT_KEY, DEFAULT_NUM_REPLICA_COUNT);
-    if (replicaCount == DEFAULT_NUM_REPLICA_COUNT) return;
+
+    if (replicaCount == DEFAULT_NUM_REPLICA_COUNT) {
+      return;
+    }
 
     TableName t = getTablename();
     Admin admin = util.getAdmin();
@@ -588,7 +603,10 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
     );
 
     int replicaCount = conf.getInt(NUM_REPLICA_COUNT_KEY, DEFAULT_NUM_REPLICA_COUNT);
-    if (replicaCount == DEFAULT_NUM_REPLICA_COUNT) return;
+
+    if (replicaCount == DEFAULT_NUM_REPLICA_COUNT) {
+      return;
+    }
 
     TableName t = getTablename();
     HBaseTestingUtility.setReplicas(util.getAdmin(), t, replicaCount);
@@ -605,7 +623,8 @@ public class IntegrationTestSparkBulkLoad extends IntegrationTestBase {
 
     // Scale this up on a real cluster
     if (util.isDistributedCluster()) {
-      util.getConfiguration().setIfUnset(BULKLOAD_PARTITIONS_NUM, String.valueOf(DEFAULT_BULKLOAD_PARTITIONS_NUM));
+      util.getConfiguration().setIfUnset(BULKLOAD_PARTITIONS_NUM,
+              String.valueOf(DEFAULT_BULKLOAD_PARTITIONS_NUM));
       util.getConfiguration().setIfUnset(BULKLOAD_IMPORT_ROUNDS, "1");
     } else {
       util.startMiniMapReduceCluster();