HBASE-19597 Fixed Checkstyle errors in hbase-spark and enabled Checkstyle to fail on violations

hbase-spark/pom.xml

@@ -713,6 +713,22 @@
           </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>
   <profiles>

hbase-spark/src/main/java/org/apache/hadoop/hbase/spark/SparkSQLPushDownFilter.java

@@ -17,10 +17,15 @@
 
 package org.apache.hadoop.hbase.spark;
 
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 import org.apache.hadoop.hbase.Cell;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.filter.FilterBase;
 import org.apache.hadoop.hbase.spark.datasources.BytesEncoder;
@@ -29,16 +34,12 @@ import org.apache.hadoop.hbase.spark.protobuf.generated.SparkFilterProtos;
 import org.apache.hadoop.hbase.util.ByteStringer;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.spark.sql.datasources.hbase.Field;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import scala.collection.mutable.MutableList;
 
-
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.ByteString;
-
 /**
  * This filter will push down all qualifier logic given to us
  * by SparkSQL so that we have make the filters at the region server level
@@ -179,7 +180,7 @@ public class SparkSQLPushDownFilter extends FilterBase{
   /**
    * @param pbBytes A pb serialized instance
    * @return An instance of SparkSQLPushDownFilter
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws DeserializationException if the filter cannot be parsed from the given bytes
    */
   @SuppressWarnings("unused")
   public static SparkSQLPushDownFilter parseFrom(final byte[] pbBytes)

hbase-spark/src/main/java/org/apache/hadoop/hbase/spark/example/hbasecontext/JavaHBaseBulkDeleteExample.java

@@ -16,6 +16,9 @@
  */
 package org.apache.hadoop.hbase.spark.example.hbasecontext;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.TableName;
@@ -27,9 +30,6 @@ import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
 import org.apache.spark.api.java.function.Function;
 
-import java.util.ArrayList;
-import java.util.List;
-
 /**
  * This is a simple example of deleting records in HBase
  * with the bulkDelete function.

hbase-spark/src/main/java/org/apache/hadoop/hbase/spark/example/hbasecontext/JavaHBaseBulkLoadExample.java

@@ -16,6 +16,10 @@
  */
 package org.apache.hadoop.hbase.spark.example.hbasecontext;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.HConstants;
@@ -25,23 +29,21 @@ import org.apache.hadoop.hbase.spark.JavaHBaseContext;
 import org.apache.hadoop.hbase.spark.KeyFamilyQualifier;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.spark.SparkConf;
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
-import org.apache.spark.SparkConf;
 import org.apache.spark.api.java.function.Function;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-
 /**
  * Run this example using command below:
  *
- *  SPARK_HOME/bin/spark-submit --master local[2] --class org.apache.hadoop.hbase.spark.example.hbasecontext.JavaHBaseBulkLoadExample
+ *  SPARK_HOME/bin/spark-submit --master local[2]
+ *  --class org.apache.hadoop.hbase.spark.example.hbasecontext.JavaHBaseBulkLoadExample
  *  path/to/hbase-spark.jar {path/to/output/HFiles}
  *
  * This example will output put hfiles in {path/to/output/HFiles}, and user can run
- * 'hbase org.apache.hadoop.hbase.tool.LoadIncrementalHFiles' to load the HFiles into table to verify this example.
+ * 'hbase org.apache.hadoop.hbase.tool.LoadIncrementalHFiles' to load the HFiles into table to
+ * verify this example.
  */
 final public class JavaHBaseBulkLoadExample {
   private JavaHBaseBulkLoadExample() {}
@@ -85,17 +87,21 @@ final public class JavaHBaseBulkLoadExample {
     }
   }
 
-  public static class BulkLoadFunction implements Function<String, Pair<KeyFamilyQualifier, byte[]>> {
+  public static class BulkLoadFunction
-
+          implements Function<String, Pair<KeyFamilyQualifier, byte[]>> {
     @Override
     public Pair<KeyFamilyQualifier, byte[]> call(String v1) throws Exception {
-      if (v1 == null)
+      if (v1 == null) {
         return null;
+      }
+
       String[] strs = v1.split(",");
-      if(strs.length != 4)
+      if(strs.length != 4) {
         return null;
-      KeyFamilyQualifier kfq = new KeyFamilyQualifier(Bytes.toBytes(strs[0]), Bytes.toBytes(strs[1]),
+      }
-          Bytes.toBytes(strs[2]));
+
+      KeyFamilyQualifier kfq = new KeyFamilyQualifier(Bytes.toBytes(strs[0]),
+              Bytes.toBytes(strs[1]), Bytes.toBytes(strs[2]));
       return new Pair(kfq, Bytes.toBytes(strs[3]));
     }
   }

hbase-spark/src/test/java/org/apache/hadoop/hbase/spark/TestJavaHBaseContext.java

@@ -20,16 +20,16 @@ import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
-import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
@@ -41,12 +41,11 @@ 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.tool.LoadIncrementalHFiles;
 import org.apache.hadoop.hbase.spark.example.hbasecontext.JavaHBaseBulkDeleteExample;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.MiscTests;
+import org.apache.hadoop.hbase.tool.LoadIncrementalHFiles;
 import org.apache.hadoop.hbase.util.Bytes;
-
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
@@ -61,6 +60,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import scala.Tuple2;
+
 import org.apache.hadoop.hbase.shaded.com.google.common.io.Files;
 
 @Category({MiscTests.class, MediumTests.class})
@@ -317,10 +317,12 @@ public class TestJavaHBaseContext implements Serializable {
 
 
 
-    hbaseContext.bulkLoad(rdd, TableName.valueOf(tableName), new BulkLoadFunction(), output.toUri().getPath(),
+    hbaseContext.bulkLoad(rdd, TableName.valueOf(tableName), new BulkLoadFunction(),
-        new HashMap<byte[], FamilyHFileWriteOptions>(), false, HConstants.DEFAULT_MAX_FILE_SIZE);
+            output.toUri().getPath(), new HashMap<byte[], FamilyHFileWriteOptions>(), false,
+            HConstants.DEFAULT_MAX_FILE_SIZE);
 
-    try (Connection conn = ConnectionFactory.createConnection(conf); Admin admin = conn.getAdmin()) {
+    try (Connection conn = ConnectionFactory.createConnection(conf);
+         Admin admin = conn.getAdmin()) {
       Table table = conn.getTable(TableName.valueOf(tableName));
       // Do bulk load
       LoadIncrementalHFiles load = new LoadIncrementalHFiles(conf);
@@ -387,11 +389,13 @@ public class TestJavaHBaseContext implements Serializable {
     Configuration conf = htu.getConfiguration();
     JavaHBaseContext hbaseContext = new JavaHBaseContext(jsc, conf);
 
-    hbaseContext.bulkLoadThinRows(rdd, TableName.valueOf(tableName), new BulkLoadThinRowsFunction(), output.toString(),
+    hbaseContext.bulkLoadThinRows(rdd, TableName.valueOf(tableName), new BulkLoadThinRowsFunction(),
-        new HashMap<byte[], FamilyHFileWriteOptions>(), false, HConstants.DEFAULT_MAX_FILE_SIZE);
+            output.toString(), new HashMap<byte[], FamilyHFileWriteOptions>(), false,
+            HConstants.DEFAULT_MAX_FILE_SIZE);
 
 
-    try (Connection conn = ConnectionFactory.createConnection(conf); Admin admin = conn.getAdmin()) {
+    try (Connection conn = ConnectionFactory.createConnection(conf);
+         Admin admin = conn.getAdmin()) {
       Table table = conn.getTable(TableName.valueOf(tableName));
       // Do bulk load
       LoadIncrementalHFiles load = new LoadIncrementalHFiles(conf);
@@ -429,25 +433,31 @@ public class TestJavaHBaseContext implements Serializable {
     }
 
   }
-  public static class BulkLoadFunction implements Function<String, Pair<KeyFamilyQualifier, byte[]>> {
+  public static class BulkLoadFunction
-
+          implements Function<String, Pair<KeyFamilyQualifier, byte[]>> {
     @Override public Pair<KeyFamilyQualifier, byte[]> call(String v1) throws Exception {
-      if (v1 == null)
+      if (v1 == null) {
         return null;
+      }
+
       String[] strs = v1.split(",");
-      if(strs.length != 4)
+      if(strs.length != 4) {
         return null;
-      KeyFamilyQualifier kfq = new KeyFamilyQualifier(Bytes.toBytes(strs[0]), Bytes.toBytes(strs[1]),
+      }
-          Bytes.toBytes(strs[2]));
+
+      KeyFamilyQualifier kfq = new KeyFamilyQualifier(Bytes.toBytes(strs[0]),
+              Bytes.toBytes(strs[1]), Bytes.toBytes(strs[2]));
       return new Pair(kfq, Bytes.toBytes(strs[3]));
     }
   }
 
-  public static class BulkLoadThinRowsFunction implements Function<List<String>, Pair<ByteArrayWrapper, FamiliesQualifiersValues>> {
+  public static class BulkLoadThinRowsFunction
-
+          implements Function<List<String>, Pair<ByteArrayWrapper, FamiliesQualifiersValues>> {
-    @Override public Pair<ByteArrayWrapper, FamiliesQualifiersValues> call(List<String> list) throws Exception {
+    @Override public Pair<ByteArrayWrapper, FamiliesQualifiersValues> call(List<String> list) {
-      if (list == null)
+      if (list == null) {
         return null;
+      }
+
       ByteArrayWrapper rowKey = null;
       FamiliesQualifiersValues fqv = new FamiliesQualifiersValues();
       for (String cell : list) {