[SPARK-14011][CORE][SQL] Enable `LineLength` Java checkstyle rule

## What changes were proposed in this pull request?

[Spark Coding Style Guide](https://cwiki.apache.org/confluence/display/SPARK/Spark+Code+Style+Guide) has 100-character limit on lines, but it's disabled for Java since 11/09/15. This PR enables **LineLength** checkstyle again. To help that, this also introduces **RedundantImport** and **RedundantModifier**, too. The following is the diff on `checkstyle.xml`.

```xml
-        <!-- TODO: 11/09/15 disabled - the lengths are currently > 100 in many places -->
-        <!--
         <module name="LineLength">
             <property name="max" value="100"/>
             <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
         </module>
-        -->
         <module name="NoLineWrap"/>
         <module name="EmptyBlock">
             <property name="option" value="TEXT"/>
 -167,5 +164,7
         </module>
         <module name="CommentsIndentation"/>
         <module name="UnusedImports"/>
+        <module name="RedundantImport"/>
+        <module name="RedundantModifier"/>
```

## How was this patch tested?

Currently, `lint-java` is disabled in Jenkins. It needs a manual test.
After passing the Jenkins tests, `dev/lint-java` should passes locally.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11831 from dongjoon-hyun/SPARK-14011.

8 files changed, 128 insertions, 126 deletions

diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
index 57e8218f3b..acf6c583bb 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
@@ -236,8 +236,8 @@ public final class UnsafeFixedWidthAggregationMap {
   /**
    * Sorts the map's records in place, spill them to disk, and returns an [[UnsafeKVExternalSorter]]
    *
-   * Note that the map will be reset for inserting new records, and the returned sorter can NOT be used
-   * to insert records.
+   * Note that the map will be reset for inserting new records, and the returned sorter can NOT be
+   * used to insert records.
    */
   public UnsafeKVExternalSorter destructAndCreateExternalSorter() throws IOException {
     return new UnsafeKVExternalSorter(
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeKVExternalSorter.java b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeKVExternalSorter.java
index 51e10b0e93..9e08675c3e 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeKVExternalSorter.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeKVExternalSorter.java
@@ -198,7 +198,7 @@ public final class UnsafeKVExternalSorter {
     private final UnsafeRow row2;
     private final int numKeyFields;
 
-    public KVComparator(BaseOrdering ordering, int numKeyFields) {
+    KVComparator(BaseOrdering ordering, int numKeyFields) {
       this.numKeyFields = numKeyFields;
       this.row1 = new UnsafeRow(numKeyFields);
       this.row2 = new UnsafeRow(numKeyFields);
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnVector.java b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnVector.java
index ffcc9c2ace..04adf1fb6d 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnVector.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnVector.java
@@ -94,7 +94,7 @@ public abstract class ColumnVector {
     }
 
     @Override
-    public final int numElements() { return length; }
+    public int numElements() { return length; }
 
     @Override
     public ArrayData copy() {
@@ -175,10 +175,10 @@ public abstract class ColumnVector {
     }
 
     @Override
-    public final boolean isNullAt(int ordinal) { return data.getIsNull(offset + ordinal); }
+    public boolean isNullAt(int ordinal) { return data.getIsNull(offset + ordinal); }
 
     @Override
-    public final boolean getBoolean(int ordinal) {
+    public boolean getBoolean(int ordinal) {
       throw new NotImplementedException();
     }
 
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnarBatch.java b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnarBatch.java
index c462ab1a13..b6fa9a0b9e 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnarBatch.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ColumnarBatch.java
@@ -115,20 +115,20 @@ public final class ColumnarBatch {
      * Marks this row as being filtered out. This means a subsequent iteration over the rows
      * in this batch will not include this row.
      */
-    public final void markFiltered() {
+    public void markFiltered() {
       parent.markFiltered(rowId);
     }
 
     public ColumnVector[] columns() { return columns; }
 
     @Override
-    public final int numFields() { return columns.length; }
+    public int numFields() { return columns.length; }
 
     @Override
     /**
      * Revisit this. This is expensive. This is currently only used in test paths.
      */
-    public final InternalRow copy() {
+    public InternalRow copy() {
       GenericMutableRow row = new GenericMutableRow(columns.length);
       for (int i = 0; i < numFields(); i++) {
         if (isNullAt(i)) {
@@ -163,73 +163,73 @@ public final class ColumnarBatch {
     }
 
     @Override
-    public final boolean anyNull() {
+    public boolean anyNull() {
       throw new NotImplementedException();
     }
 
     @Override
-    public final boolean isNullAt(int ordinal) { return columns[ordinal].getIsNull(rowId); }
+    public boolean isNullAt(int ordinal) { return columns[ordinal].getIsNull(rowId); }
 
     @Override
-    public final boolean getBoolean(int ordinal) { return columns[ordinal].getBoolean(rowId); }
+    public boolean getBoolean(int ordinal) { return columns[ordinal].getBoolean(rowId); }
 
     @Override
-    public final byte getByte(int ordinal) { return columns[ordinal].getByte(rowId); }
+    public byte getByte(int ordinal) { return columns[ordinal].getByte(rowId); }
 
     @Override
-    public final short getShort(int ordinal) { return columns[ordinal].getShort(rowId); }
+    public short getShort(int ordinal) { return columns[ordinal].getShort(rowId); }
 
     @Override
-    public final int getInt(int ordinal) { return columns[ordinal].getInt(rowId); }
+    public int getInt(int ordinal) { return columns[ordinal].getInt(rowId); }
 
     @Override
-    public final long getLong(int ordinal) { return columns[ordinal].getLong(rowId); }
+    public long getLong(int ordinal) { return columns[ordinal].getLong(rowId); }
 
     @Override
-    public final float getFloat(int ordinal) { return columns[ordinal].getFloat(rowId); }
+    public float getFloat(int ordinal) { return columns[ordinal].getFloat(rowId); }
 
     @Override
-    public final double getDouble(int ordinal) { return columns[ordinal].getDouble(rowId); }
+    public double getDouble(int ordinal) { return columns[ordinal].getDouble(rowId); }
 
     @Override
-    public final Decimal getDecimal(int ordinal, int precision, int scale) {
+    public Decimal getDecimal(int ordinal, int precision, int scale) {
       return columns[ordinal].getDecimal(rowId, precision, scale);
     }
 
     @Override
-    public final UTF8String getUTF8String(int ordinal) {
+    public UTF8String getUTF8String(int ordinal) {
       return columns[ordinal].getUTF8String(rowId);
     }
 
     @Override
-    public final byte[] getBinary(int ordinal) {
+    public byte[] getBinary(int ordinal) {
       return columns[ordinal].getBinary(rowId);
     }
 
     @Override
-    public final CalendarInterval getInterval(int ordinal) {
+    public CalendarInterval getInterval(int ordinal) {
       final int months = columns[ordinal].getChildColumn(0).getInt(rowId);
       final long microseconds = columns[ordinal].getChildColumn(1).getLong(rowId);
       return new CalendarInterval(months, microseconds);
     }
 
     @Override
-    public final InternalRow getStruct(int ordinal, int numFields) {
+    public InternalRow getStruct(int ordinal, int numFields) {
       return columns[ordinal].getStruct(rowId);
     }
 
     @Override
-    public final ArrayData getArray(int ordinal) {
+    public ArrayData getArray(int ordinal) {
       return columns[ordinal].getArray(rowId);
     }
 
     @Override
-    public final MapData getMap(int ordinal) {
+    public MapData getMap(int ordinal) {
       throw new NotImplementedException();
     }
 
     @Override
-    public final Object get(int ordinal, DataType dataType) {
+    public Object get(int ordinal, DataType dataType) {
       throw new NotImplementedException();
     }
   }
@@ -357,7 +357,7 @@ public final class ColumnarBatch {
    * Marks this row as being filtered out. This means a subsequent iteration over the rows
    * in this batch will not include this row.
    */
-  public final void markFiltered(int rowId) {
+  public void markFiltered(int rowId) {
     assert(!filteredRows[rowId]);
     filteredRows[rowId] = true;
     ++numRowsFiltered;
@@ -367,7 +367,7 @@ public final class ColumnarBatch {
    * Marks a given column as non-nullable. Any row that has a NULL value for the corresponding
    * attribute is filtered out.
    */
-  public final void filterNullsInColumn(int ordinal) {
+  public void filterNullsInColumn(int ordinal) {
     nullFilteredColumns.add(ordinal);
   }
 
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OffHeapColumnVector.java b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OffHeapColumnVector.java
index b06b7f2457..d5a9163274 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OffHeapColumnVector.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OffHeapColumnVector.java
@@ -52,7 +52,7 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final long valuesNativeAddress() {
+  public long valuesNativeAddress() {
     return data;
   }
 
@@ -62,7 +62,7 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void close() {
+  public void close() {
     Platform.freeMemory(nulls);
     Platform.freeMemory(data);
     Platform.freeMemory(lengthData);
@@ -78,19 +78,19 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putNotNull(int rowId) {
+  public void putNotNull(int rowId) {
     Platform.putByte(null, nulls + rowId, (byte) 0);
   }
 
   @Override
-  public final void putNull(int rowId) {
+  public void putNull(int rowId) {
     Platform.putByte(null, nulls + rowId, (byte) 1);
     ++numNulls;
     anyNullsSet = true;
   }
 
   @Override
-  public final void putNulls(int rowId, int count) {
+  public void putNulls(int rowId, int count) {
     long offset = nulls + rowId;
     for (int i = 0; i < count; ++i, ++offset) {
       Platform.putByte(null, offset, (byte) 1);
@@ -100,7 +100,7 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putNotNulls(int rowId, int count) {
+  public void putNotNulls(int rowId, int count) {
     if (!anyNullsSet) return;
     long offset = nulls + rowId;
     for (int i = 0; i < count; ++i, ++offset) {
@@ -109,7 +109,7 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final boolean getIsNull(int rowId) {
+  public boolean getIsNull(int rowId) {
     return Platform.getByte(null, nulls + rowId) == 1;
   }
 
@@ -118,12 +118,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putBoolean(int rowId, boolean value) {
+  public void putBoolean(int rowId, boolean value) {
     Platform.putByte(null, data + rowId, (byte)((value) ? 1 : 0));
   }
 
   @Override
-  public final void putBooleans(int rowId, int count, boolean value) {
+  public void putBooleans(int rowId, int count, boolean value) {
     byte v = (byte)((value) ? 1 : 0);
     for (int i = 0; i < count; ++i) {
       Platform.putByte(null, data + rowId + i, v);
@@ -131,32 +131,32 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final boolean getBoolean(int rowId) { return Platform.getByte(null, data + rowId) == 1; }
+  public boolean getBoolean(int rowId) { return Platform.getByte(null, data + rowId) == 1; }
 
   //
   // APIs dealing with Bytes
   //
 
   @Override
-  public final void putByte(int rowId, byte value) {
+  public void putByte(int rowId, byte value) {
     Platform.putByte(null, data + rowId, value);
 
   }
 
   @Override
-  public final void putBytes(int rowId, int count, byte value) {
+  public void putBytes(int rowId, int count, byte value) {
     for (int i = 0; i < count; ++i) {
       Platform.putByte(null, data + rowId + i, value);
     }
   }
 
   @Override
-  public final void putBytes(int rowId, int count, byte[] src, int srcIndex) {
+  public void putBytes(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.BYTE_ARRAY_OFFSET + srcIndex, null, data + rowId, count);
   }
 
   @Override
-  public final byte getByte(int rowId) {
+  public byte getByte(int rowId) {
     if (dictionary == null) {
       return Platform.getByte(null, data + rowId);
     } else {
@@ -169,12 +169,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putShort(int rowId, short value) {
+  public void putShort(int rowId, short value) {
     Platform.putShort(null, data + 2 * rowId, value);
   }
 
   @Override
-  public final void putShorts(int rowId, int count, short value) {
+  public void putShorts(int rowId, int count, short value) {
     long offset = data + 2 * rowId;
     for (int i = 0; i < count; ++i, offset += 4) {
       Platform.putShort(null, offset, value);
@@ -182,13 +182,13 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putShorts(int rowId, int count, short[] src, int srcIndex) {
+  public void putShorts(int rowId, int count, short[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.SHORT_ARRAY_OFFSET + srcIndex * 2,
         null, data + 2 * rowId, count * 2);
   }
 
   @Override
-  public final short getShort(int rowId) {
+  public short getShort(int rowId) {
     if (dictionary == null) {
       return Platform.getShort(null, data + 2 * rowId);
     } else {
@@ -201,12 +201,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putInt(int rowId, int value) {
+  public void putInt(int rowId, int value) {
     Platform.putInt(null, data + 4 * rowId, value);
   }
 
   @Override
-  public final void putInts(int rowId, int count, int value) {
+  public void putInts(int rowId, int count, int value) {
     long offset = data + 4 * rowId;
     for (int i = 0; i < count; ++i, offset += 4) {
       Platform.putInt(null, offset, value);
@@ -214,19 +214,19 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putInts(int rowId, int count, int[] src, int srcIndex) {
+  public void putInts(int rowId, int count, int[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.INT_ARRAY_OFFSET + srcIndex * 4,
         null, data + 4 * rowId, count * 4);
   }
 
   @Override
-  public final void putIntsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
+  public void putIntsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, srcIndex + Platform.BYTE_ARRAY_OFFSET,
         null, data + 4 * rowId, count * 4);
   }
 
   @Override
-  public final int getInt(int rowId) {
+  public int getInt(int rowId) {
     if (dictionary == null) {
       return Platform.getInt(null, data + 4 * rowId);
     } else {
@@ -239,12 +239,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putLong(int rowId, long value) {
+  public void putLong(int rowId, long value) {
     Platform.putLong(null, data + 8 * rowId, value);
   }
 
   @Override
-  public final void putLongs(int rowId, int count, long value) {
+  public void putLongs(int rowId, int count, long value) {
     long offset = data + 8 * rowId;
     for (int i = 0; i < count; ++i, offset += 8) {
       Platform.putLong(null, offset, value);
@@ -252,19 +252,19 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putLongs(int rowId, int count, long[] src, int srcIndex) {
+  public void putLongs(int rowId, int count, long[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.LONG_ARRAY_OFFSET + srcIndex * 8,
         null, data + 8 * rowId, count * 8);
   }
 
   @Override
-  public final void putLongsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
+  public void putLongsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, srcIndex + Platform.BYTE_ARRAY_OFFSET,
         null, data + 8 * rowId, count * 8);
   }
 
   @Override
-  public final long getLong(int rowId) {
+  public long getLong(int rowId) {
     if (dictionary == null) {
       return Platform.getLong(null, data + 8 * rowId);
     } else {
@@ -277,12 +277,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putFloat(int rowId, float value) {
+  public void putFloat(int rowId, float value) {
     Platform.putFloat(null, data + rowId * 4, value);
   }
 
   @Override
-  public final void putFloats(int rowId, int count, float value) {
+  public void putFloats(int rowId, int count, float value) {
     long offset = data + 4 * rowId;
     for (int i = 0; i < count; ++i, offset += 4) {
       Platform.putFloat(null, offset, value);
@@ -290,19 +290,19 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putFloats(int rowId, int count, float[] src, int srcIndex) {
+  public void putFloats(int rowId, int count, float[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.FLOAT_ARRAY_OFFSET + srcIndex * 4,
         null, data + 4 * rowId, count * 4);
   }
 
   @Override
-  public final void putFloats(int rowId, int count, byte[] src, int srcIndex) {
+  public void putFloats(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.BYTE_ARRAY_OFFSET + srcIndex,
         null, data + rowId * 4, count * 4);
   }
 
   @Override
-  public final float getFloat(int rowId) {
+  public float getFloat(int rowId) {
     if (dictionary == null) {
       return Platform.getFloat(null, data + rowId * 4);
     } else {
@@ -316,12 +316,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putDouble(int rowId, double value) {
+  public void putDouble(int rowId, double value) {
     Platform.putDouble(null, data + rowId * 8, value);
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, double value) {
+  public void putDoubles(int rowId, int count, double value) {
     long offset = data + 8 * rowId;
     for (int i = 0; i < count; ++i, offset += 8) {
       Platform.putDouble(null, offset, value);
@@ -329,19 +329,19 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, double[] src, int srcIndex) {
+  public void putDoubles(int rowId, int count, double[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.DOUBLE_ARRAY_OFFSET + srcIndex * 8,
       null, data + 8 * rowId, count * 8);
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, byte[] src, int srcIndex) {
+  public void putDoubles(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.BYTE_ARRAY_OFFSET + srcIndex,
         null, data + rowId * 8, count * 8);
   }
 
   @Override
-  public final double getDouble(int rowId) {
+  public double getDouble(int rowId) {
     if (dictionary == null) {
       return Platform.getDouble(null, data + rowId * 8);
     } else {
@@ -353,25 +353,25 @@ public final class OffHeapColumnVector extends ColumnVector {
   // APIs dealing with Arrays.
   //
   @Override
-  public final void putArray(int rowId, int offset, int length) {
+  public void putArray(int rowId, int offset, int length) {
     assert(offset >= 0 && offset + length <= childColumns[0].capacity);
     Platform.putInt(null, lengthData + 4 * rowId, length);
     Platform.putInt(null, offsetData + 4 * rowId, offset);
   }
 
   @Override
-  public final int getArrayLength(int rowId) {
+  public int getArrayLength(int rowId) {
     return Platform.getInt(null, lengthData + 4 * rowId);
   }
 
   @Override
-  public final int getArrayOffset(int rowId) {
+  public int getArrayOffset(int rowId) {
     return Platform.getInt(null, offsetData + 4 * rowId);
   }
 
   // APIs dealing with ByteArrays
   @Override
-  public final int putByteArray(int rowId, byte[] value, int offset, int length) {
+  public int putByteArray(int rowId, byte[] value, int offset, int length) {
     int result = arrayData().appendBytes(length, value, offset);
     Platform.putInt(null, lengthData + 4 * rowId, length);
     Platform.putInt(null, offsetData + 4 * rowId, result);
@@ -379,7 +379,7 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void loadBytes(ColumnVector.Array array) {
+  public void loadBytes(ColumnVector.Array array) {
     if (array.tmpByteArray.length < array.length) array.tmpByteArray = new byte[array.length];
     Platform.copyMemory(
         null, data + array.offset, array.tmpByteArray, Platform.BYTE_ARRAY_OFFSET, array.length);
@@ -388,12 +388,12 @@ public final class OffHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void reserve(int requiredCapacity) {
+  public void reserve(int requiredCapacity) {
     if (requiredCapacity > capacity) reserveInternal(requiredCapacity * 2);
   }
 
   // Split out the slow path.
-  private final void reserveInternal(int newCapacity) {
+  private void reserveInternal(int newCapacity) {
     if (this.resultArray != null) {
       this.lengthData =
           Platform.reallocateMemory(lengthData, elementsAppended * 4, newCapacity * 4);
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OnHeapColumnVector.java b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OnHeapColumnVector.java
index 03160d1ec3..5b671a7432 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OnHeapColumnVector.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OnHeapColumnVector.java
@@ -52,16 +52,16 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final long valuesNativeAddress() {
+  public long valuesNativeAddress() {
     throw new RuntimeException("Cannot get native address for on heap column");
   }
   @Override
-  public final long nullsNativeAddress() {
+  public long nullsNativeAddress() {
     throw new RuntimeException("Cannot get native address for on heap column");
   }
 
   @Override
-  public final void close() {
+  public void close() {
   }
 
   //
@@ -69,19 +69,19 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putNotNull(int rowId) {
+  public void putNotNull(int rowId) {
     nulls[rowId] = (byte)0;
   }
 
   @Override
-  public final void putNull(int rowId) {
+  public void putNull(int rowId) {
     nulls[rowId] = (byte)1;
     ++numNulls;
     anyNullsSet = true;
   }
 
   @Override
-  public final void putNulls(int rowId, int count) {
+  public void putNulls(int rowId, int count) {
     for (int i = 0; i < count; ++i) {
       nulls[rowId + i] = (byte)1;
     }
@@ -90,7 +90,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void putNotNulls(int rowId, int count) {
+  public void putNotNulls(int rowId, int count) {
     if (!anyNullsSet) return;
     for (int i = 0; i < count; ++i) {
       nulls[rowId + i] = (byte)0;
@@ -98,7 +98,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final boolean getIsNull(int rowId) {
+  public boolean getIsNull(int rowId) {
     return nulls[rowId] == 1;
   }
 
@@ -107,12 +107,12 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putBoolean(int rowId, boolean value) {
+  public void putBoolean(int rowId, boolean value) {
     byteData[rowId] = (byte)((value) ? 1 : 0);
   }
 
   @Override
-  public final void putBooleans(int rowId, int count, boolean value) {
+  public void putBooleans(int rowId, int count, boolean value) {
     byte v = (byte)((value) ? 1 : 0);
     for (int i = 0; i < count; ++i) {
       byteData[i + rowId] = v;
@@ -120,7 +120,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final boolean getBoolean(int rowId) {
+  public boolean getBoolean(int rowId) {
     return byteData[rowId] == 1;
   }
 
@@ -131,24 +131,24 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putByte(int rowId, byte value) {
+  public void putByte(int rowId, byte value) {
     byteData[rowId] = value;
   }
 
   @Override
-  public final void putBytes(int rowId, int count, byte value) {
+  public void putBytes(int rowId, int count, byte value) {
     for (int i = 0; i < count; ++i) {
       byteData[i + rowId] = value;
     }
   }
 
   @Override
-  public final void putBytes(int rowId, int count, byte[] src, int srcIndex) {
+  public void putBytes(int rowId, int count, byte[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, byteData, rowId, count);
   }
 
   @Override
-  public final byte getByte(int rowId) {
+  public byte getByte(int rowId) {
     if (dictionary == null) {
       return byteData[rowId];
     } else {
@@ -161,24 +161,24 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putShort(int rowId, short value) {
+  public void putShort(int rowId, short value) {
     shortData[rowId] = value;
   }
 
   @Override
-  public final void putShorts(int rowId, int count, short value) {
+  public void putShorts(int rowId, int count, short value) {
     for (int i = 0; i < count; ++i) {
       shortData[i + rowId] = value;
     }
   }
 
   @Override
-  public final void putShorts(int rowId, int count, short[] src, int srcIndex) {
+  public void putShorts(int rowId, int count, short[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, shortData, rowId, count);
   }
 
   @Override
-  public final short getShort(int rowId) {
+  public short getShort(int rowId) {
     if (dictionary == null) {
       return shortData[rowId];
     } else {
@@ -192,24 +192,24 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putInt(int rowId, int value) {
+  public void putInt(int rowId, int value) {
     intData[rowId] = value;
   }
 
   @Override
-  public final void putInts(int rowId, int count, int value) {
+  public void putInts(int rowId, int count, int value) {
     for (int i = 0; i < count; ++i) {
       intData[i + rowId] = value;
     }
   }
 
   @Override
-  public final void putInts(int rowId, int count, int[] src, int srcIndex) {
+  public void putInts(int rowId, int count, int[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, intData, rowId, count);
   }
 
   @Override
-  public final void putIntsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
+  public void putIntsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
     int srcOffset = srcIndex + Platform.BYTE_ARRAY_OFFSET;
     for (int i = 0; i < count; ++i) {
       intData[i + rowId] = Platform.getInt(src, srcOffset);;
@@ -219,7 +219,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final int getInt(int rowId) {
+  public int getInt(int rowId) {
     if (dictionary == null) {
       return intData[rowId];
     } else {
@@ -232,24 +232,24 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putLong(int rowId, long value) {
+  public void putLong(int rowId, long value) {
     longData[rowId] = value;
   }
 
   @Override
-  public final void putLongs(int rowId, int count, long value) {
+  public void putLongs(int rowId, int count, long value) {
     for (int i = 0; i < count; ++i) {
       longData[i + rowId] = value;
     }
   }
 
   @Override
-  public final void putLongs(int rowId, int count, long[] src, int srcIndex) {
+  public void putLongs(int rowId, int count, long[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, longData, rowId, count);
   }
 
   @Override
-  public final void putLongsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
+  public void putLongsLittleEndian(int rowId, int count, byte[] src, int srcIndex) {
     int srcOffset = srcIndex + Platform.BYTE_ARRAY_OFFSET;
     for (int i = 0; i < count; ++i) {
       longData[i + rowId] = Platform.getLong(src, srcOffset);
@@ -259,7 +259,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final long getLong(int rowId) {
+  public long getLong(int rowId) {
     if (dictionary == null) {
       return longData[rowId];
     } else {
@@ -272,26 +272,26 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putFloat(int rowId, float value) { floatData[rowId] = value; }
+  public void putFloat(int rowId, float value) { floatData[rowId] = value; }
 
   @Override
-  public final void putFloats(int rowId, int count, float value) {
+  public void putFloats(int rowId, int count, float value) {
     Arrays.fill(floatData, rowId, rowId + count, value);
   }
 
   @Override
-  public final void putFloats(int rowId, int count, float[] src, int srcIndex) {
+  public void putFloats(int rowId, int count, float[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, floatData, rowId, count);
   }
 
   @Override
-  public final void putFloats(int rowId, int count, byte[] src, int srcIndex) {
+  public void putFloats(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.BYTE_ARRAY_OFFSET + srcIndex,
         floatData, Platform.DOUBLE_ARRAY_OFFSET + rowId * 4, count * 4);
   }
 
   @Override
-  public final float getFloat(int rowId) {
+  public float getFloat(int rowId) {
     if (dictionary == null) {
       return floatData[rowId];
     } else {
@@ -304,28 +304,28 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final void putDouble(int rowId, double value) {
+  public void putDouble(int rowId, double value) {
     doubleData[rowId] = value;
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, double value) {
+  public void putDoubles(int rowId, int count, double value) {
     Arrays.fill(doubleData, rowId, rowId + count, value);
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, double[] src, int srcIndex) {
+  public void putDoubles(int rowId, int count, double[] src, int srcIndex) {
     System.arraycopy(src, srcIndex, doubleData, rowId, count);
   }
 
   @Override
-  public final void putDoubles(int rowId, int count, byte[] src, int srcIndex) {
+  public void putDoubles(int rowId, int count, byte[] src, int srcIndex) {
     Platform.copyMemory(src, Platform.BYTE_ARRAY_OFFSET + srcIndex, doubleData,
         Platform.DOUBLE_ARRAY_OFFSET + rowId * 8, count * 8);
   }
 
   @Override
-  public final double getDouble(int rowId) {
+  public double getDouble(int rowId) {
     if (dictionary == null) {
       return doubleData[rowId];
     } else {
@@ -338,22 +338,22 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final int getArrayLength(int rowId) {
+  public int getArrayLength(int rowId) {
     return arrayLengths[rowId];
   }
   @Override
-  public final int getArrayOffset(int rowId) {
+  public int getArrayOffset(int rowId) {
     return arrayOffsets[rowId];
   }
 
   @Override
-  public final void putArray(int rowId, int offset, int length) {
+  public void putArray(int rowId, int offset, int length) {
     arrayOffsets[rowId] = offset;
     arrayLengths[rowId] = length;
   }
 
   @Override
-  public final void loadBytes(ColumnVector.Array array) {
+  public void loadBytes(ColumnVector.Array array) {
     array.byteArray = byteData;
     array.byteArrayOffset = array.offset;
   }
@@ -363,7 +363,7 @@ public final class OnHeapColumnVector extends ColumnVector {
   //
 
   @Override
-  public final int putByteArray(int rowId, byte[] value, int offset, int length) {
+  public int putByteArray(int rowId, byte[] value, int offset, int length) {
     int result = arrayData().appendBytes(length, value, offset);
     arrayOffsets[rowId] = result;
     arrayLengths[rowId] = length;
@@ -371,12 +371,12 @@ public final class OnHeapColumnVector extends ColumnVector {
   }
 
   @Override
-  public final void reserve(int requiredCapacity) {
+  public void reserve(int requiredCapacity) {
     if (requiredCapacity > capacity) reserveInternal(requiredCapacity * 2);
   }
 
   // Spilt this function out since it is the slow path.
-  private final void reserveInternal(int newCapacity) {
+  private void reserveInternal(int newCapacity) {
     if (this.resultArray != null || DecimalType.isByteArrayDecimalType(type)) {
       int[] newLengths = new int[newCapacity];
       int[] newOffsets = new int[newCapacity];
diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
index ae9c8cc1ba..189cc3972c 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
@@ -145,12 +145,13 @@ public class JavaApplySchemaSuite implements Serializable {
 
     Dataset<Row> df = sqlContext.createDataFrame(rowRDD, schema);
     df.registerTempTable("people");
-    List<String> actual = sqlContext.sql("SELECT * FROM people").toJavaRDD().map(new Function<Row, String>() {
-      @Override
-      public String call(Row row) {
-        return row.getString(0) + "_" + row.get(1);
-      }
-    }).collect();
+    List<String> actual = sqlContext.sql("SELECT * FROM people").toJavaRDD()
+      .map(new Function<Row, String>() {
+        @Override
+        public String call(Row row) {
+          return row.getString(0) + "_" + row.get(1);
+        }
+      }).collect();
 
     List<String> expected = new ArrayList<>(2);
     expected.add("Michael_29");
diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
index f3c5a86e20..cf764c645f 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
@@ -220,7 +220,8 @@ public class JavaDataFrameSuite {
     StructType schema1 = StructType$.MODULE$.apply(fields1);
     Assert.assertEquals(0, schema1.fieldIndex("id"));
 
-    List<StructField> fields2 = Arrays.asList(new StructField("id", DataTypes.StringType, true, Metadata.empty()));
+    List<StructField> fields2 =
+        Arrays.asList(new StructField("id", DataTypes.StringType, true, Metadata.empty()));
     StructType schema2 = StructType$.MODULE$.apply(fields2);
     Assert.assertEquals(0, schema2.fieldIndex("id"));
   }