[MINOR][BUILD] Fix Java linter errors

## What changes were proposed in this pull request?

This PR cleans up a few Java linter errors for Apache Spark 2.3 release.

## How was this patch tested?

```bash
$ dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.
```

We can see the result from [Travis CI](https://travis-ci.org/dongjoon-hyun/spark/builds/322470787), too.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #20101 from dongjoon-hyun/fix-java-lint.

core/src/main/java/org/apache/spark/memory/MemoryConsumer.java

@@ -154,6 +154,7 @@ private void throwOom(final MemoryBlock page, final long required) {
       taskMemoryManager.freePage(page, this);
     }
     taskMemoryManager.showMemoryUsage();
-    throw new SparkOutOfMemoryError("Unable to acquire " + required + " bytes of memory, got " + got);
+    throw new SparkOutOfMemoryError("Unable to acquire " + required + " bytes of memory, got " +
+      got);
   }
 }

external/kinesis-asl/src/main/java/org/apache/spark/streaming/kinesis/KinesisInitialPositions.java

@@ -67,9 +67,10 @@ public Date getTimestamp() {
 
 
     /**
-     * Returns instance of [[KinesisInitialPosition]] based on the passed [[InitialPositionInStream]].
-     * This method is used in KinesisUtils for translating the InitialPositionInStream
-     * to InitialPosition. This function would be removed when we deprecate the KinesisUtils.
+     * Returns instance of [[KinesisInitialPosition]] based on the passed
+     * [[InitialPositionInStream]]. This method is used in KinesisUtils for translating the
+     * InitialPositionInStream to InitialPosition. This function would be removed when we deprecate
+     * the KinesisUtils.
      *
      * @return [[InitialPosition]]
      */
@@ -83,9 +84,10 @@ public static KinesisInitialPosition fromKinesisInitialPosition(
             // InitialPositionInStream.AT_TIMESTAMP is not supported.
             // Use InitialPosition.atTimestamp(timestamp) instead.
             throw new UnsupportedOperationException(
-                    "Only InitialPositionInStream.LATEST and InitialPositionInStream.TRIM_HORIZON " +
-                            "supported in initialPositionInStream(). Please use the initialPosition() from " +
-                            "builder API in KinesisInputDStream for using InitialPositionInStream.AT_TIMESTAMP");
+                    "Only InitialPositionInStream.LATEST and InitialPositionInStream." +
+                            "TRIM_HORIZON supported in initialPositionInStream(). Please use " +
+                            "the initialPosition() from builder API in KinesisInputDStream for " +
+                            "using InitialPositionInStream.AT_TIMESTAMP");
         }
     }
 }

sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedColumnReader.java

@@ -31,7 +31,6 @@
 import org.apache.parquet.schema.PrimitiveType;
 
 import org.apache.spark.sql.catalyst.util.DateTimeUtils;
-import org.apache.spark.sql.execution.vectorized.ColumnVector;
 import org.apache.spark.sql.execution.vectorized.WritableColumnVector;
 import org.apache.spark.sql.types.DataTypes;
 import org.apache.spark.sql.types.DecimalType;
@@ -96,7 +95,7 @@ public class VectorizedColumnReader {
   private final OriginalType originalType;
   // The timezone conversion to apply to int96 timestamps. Null if no conversion.
   private final TimeZone convertTz;
-  private final static TimeZone UTC = DateTimeUtils.TimeZoneUTC();
+  private static final TimeZone UTC = DateTimeUtils.TimeZoneUTC();
 
   public VectorizedColumnReader(
       ColumnDescriptor descriptor,

sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedParquetRecordReader.java

@@ -79,8 +79,8 @@ public class VectorizedParquetRecordReader extends SpecificParquetRecordReaderBa
   private boolean[] missingColumns;
 
   /**
-   * The timezone that timestamp INT96 values should be converted to. Null if no conversion. Here to workaround
-   * incompatibilities between different engines when writing timestamp values.
+   * The timezone that timestamp INT96 values should be converted to. Null if no conversion. Here to
+   * workaround incompatibilities between different engines when writing timestamp values.
    */
   private TimeZone convertTz = null;
 

sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnarRow.java

@@ -28,7 +28,8 @@
  * to be reused, callers should copy the data out if it needs to be stored.
  */
 public final class ColumnarRow extends InternalRow {
-  // The data for this row. E.g. the value of 3rd int field is `data.getChildColumn(3).getInt(rowId)`.
+  // The data for this row.
+  // E.g. the value of 3rd int field is `data.getChildColumn(3).getInt(rowId)`.
   private final ColumnVector data;
   private final int rowId;
   private final int numFields;

sql/core/src/main/java/org/apache/spark/sql/sources/v2/SessionConfigSupport.java

@@ -19,9 +19,6 @@
 
 import org.apache.spark.annotation.InterfaceStability;
 
-import java.util.List;
-import java.util.Map;
-
 /**
  * A mix-in interface for {@link DataSourceV2}. Data sources can implement this interface to
  * propagate session configs with the specified key-prefix to all data source operations in this

sql/core/src/main/java/org/apache/spark/sql/sources/v2/streaming/ContinuousReadSupport.java

@@ -39,5 +39,8 @@ public interface ContinuousReadSupport extends DataSourceV2 {
    * @param options the options for the returned data source reader, which is an immutable
    *                case-insensitive string-to-string map.
    */
-  ContinuousReader createContinuousReader(Optional<StructType> schema, String checkpointLocation, DataSourceV2Options options);
+  ContinuousReader createContinuousReader(
+    Optional<StructType> schema,
+    String checkpointLocation,
+    DataSourceV2Options options);
 }

sql/core/src/main/java/org/apache/spark/sql/sources/v2/streaming/ContinuousWriteSupport.java

@@ -39,9 +39,9 @@ public interface ContinuousWriteSupport extends BaseStreamingSink {
      * Creates an optional {@link ContinuousWriter} to save the data to this data source. Data
      * sources can return None if there is no writing needed to be done.
      *
-     * @param queryId A unique string for the writing query. It's possible that there are many writing
-     *                queries running at the same time, and the returned {@link DataSourceV2Writer}
-     *                can use this id to distinguish itself from others.
+     * @param queryId A unique string for the writing query. It's possible that there are many
+     *                writing queries running at the same time, and the returned
+     *                {@link DataSourceV2Writer} can use this id to distinguish itself from others.
      * @param schema the schema of the data to be written.
      * @param mode the output mode which determines what successive epoch output means to this
      *             sink, please refer to {@link OutputMode} for more details.

sql/core/src/main/java/org/apache/spark/sql/sources/v2/streaming/reader/Offset.java

@@ -42,7 +42,8 @@ public abstract class Offset extends org.apache.spark.sql.execution.streaming.Of
     @Override
     public boolean equals(Object obj) {
         if (obj instanceof org.apache.spark.sql.execution.streaming.Offset) {
-            return this.json().equals(((org.apache.spark.sql.execution.streaming.Offset) obj).json());
+            return this.json()
+                .equals(((org.apache.spark.sql.execution.streaming.Offset) obj).json());
         } else {
             return false;
         }

sql/core/src/main/java/org/apache/spark/sql/sources/v2/streaming/reader/PartitionOffset.java

@@ -26,5 +26,4 @@
  * These offsets must be serializable.
  */
 public interface PartitionOffset extends Serializable {
-
 }

sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/operation/SQLOperation.java

@@ -42,7 +42,6 @@
 import org.apache.hadoop.hive.ql.metadata.HiveException;
 import org.apache.hadoop.hive.ql.parse.VariableSubstitution;
 import org.apache.hadoop.hive.ql.processors.CommandProcessorResponse;
-import org.apache.hadoop.hive.ql.session.OperationLog;
 import org.apache.hadoop.hive.ql.session.SessionState;
 import org.apache.hadoop.hive.serde.serdeConstants;
 import org.apache.hadoop.hive.serde2.SerDe;