[MINOR][BUILD] Fix Java linter errors

## What changes were proposed in this pull request?

This PR fixes the minor Java linter errors like the following.
```
-    public int read(char cbuf[], int off, int len) throws IOException {
+    public int read(char[] cbuf, int off, int len) throws IOException {
```

## How was this patch tested?

Manual.
```
$ build/mvn -T 4 -q -DskipTests -Pyarn -Phadoop-2.3 -Pkinesis-asl -Phive -Phive-thriftserver install
$ dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.
```

Author: Dongjoon Hyun <[email protected]>

Closes #14017 from dongjoon-hyun/minor_build_java_linter_error.

Author: dongjoon-hyun

core/src/main/java/org/apache/spark/shuffle/sort/ShuffleExternalSorter.java

@@ -376,7 +376,8 @@ public void insertRecord(Object recordBase, long recordOffset, int length, int p
     // for tests
     assert(inMemSorter != null);
     if (inMemSorter.numRecords() >= numElementsForSpillThreshold) {
-      logger.info("Spilling data because number of spilledRecords crossed the threshold " + numElementsForSpillThreshold);
+      logger.info("Spilling data because number of spilledRecords crossed the threshold " +
+        numElementsForSpillThreshold);
       spill();
     }
 

core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java

@@ -27,7 +27,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import org.apache.spark.SparkEnv;
 import org.apache.spark.TaskContext;
 import org.apache.spark.executor.ShuffleWriteMetrics;
 import org.apache.spark.memory.MemoryConsumer;
@@ -99,8 +98,8 @@ public static UnsafeExternalSorter createWithExistingInMemorySorter(
       long numElementsForSpillThreshold,
       UnsafeInMemorySorter inMemorySorter) throws IOException {
     UnsafeExternalSorter sorter = new UnsafeExternalSorter(taskMemoryManager, blockManager,
-      serializerManager, taskContext, recordComparator, prefixComparator, initialSize, numElementsForSpillThreshold,
-        pageSizeBytes, inMemorySorter, false /* ignored */);
+      serializerManager, taskContext, recordComparator, prefixComparator, initialSize,
+        numElementsForSpillThreshold, pageSizeBytes, inMemorySorter, false /* ignored */);
     sorter.spill(Long.MAX_VALUE, sorter);
     // The external sorter will be used to insert records, in-memory sorter is not needed.
     sorter.inMemSorter = null;
@@ -119,8 +118,8 @@ public static UnsafeExternalSorter create(
       long numElementsForSpillThreshold,
       boolean canUseRadixSort) {
     return new UnsafeExternalSorter(taskMemoryManager, blockManager, serializerManager,
-      taskContext, recordComparator, prefixComparator, initialSize, pageSizeBytes, numElementsForSpillThreshold, null,
-      canUseRadixSort);
+      taskContext, recordComparator, prefixComparator, initialSize, pageSizeBytes,
+      numElementsForSpillThreshold, null, canUseRadixSort);
   }
 
   private UnsafeExternalSorter(
@@ -387,7 +386,8 @@ public void insertRecord(
 
     assert(inMemSorter != null);
     if (inMemSorter.numRecords() >= numElementsForSpillThreshold) {
-      logger.info("Spilling data because number of spilledRecords crossed the threshold " + numElementsForSpillThreshold);
+      logger.info("Spilling data because number of spilledRecords crossed the threshold " +
+        numElementsForSpillThreshold);
       spill();
     }
 

sql/catalyst/src/main/java/org/apache/spark/sql/catalyst/expressions/xml/UDFXPathUtil.java

@@ -19,7 +19,6 @@
 
 import java.io.IOException;
 import java.io.Reader;
-import java.io.StringReader;
 
 import javax.xml.namespace.QName;
 import javax.xml.xpath.XPath;
@@ -71,7 +70,7 @@ public Object eval(String xml, String path, QName qname) {
     try {
       return expression.evaluate(inputSource, qname);
     } catch (XPathExpressionException e) {
-      throw new RuntimeException ("Invalid expression '" + oldPath + "'", e);
+      throw new RuntimeException("Invalid expression '" + oldPath + "'", e);
     }
   }
 
@@ -96,7 +95,7 @@ public NodeList evalNodeList(String xml, String path) {
   }
 
   /**
-   * Reusable, non-threadsafe version of {@link StringReader}.
+   * Reusable, non-threadsafe version of {@link java.io.StringReader}.
    */
   public static class ReusableStringReader extends Reader {
 
@@ -117,29 +116,32 @@ public void set(String s) {
 
     /** Check to make sure that the stream has not been closed */
     private void ensureOpen() throws IOException {
-      if (str == null)
+      if (str == null) {
         throw new IOException("Stream closed");
+      }
     }
 
     @Override
     public int read() throws IOException {
       ensureOpen();
-      if (next >= length)
+      if (next >= length) {
         return -1;
+      }
       return str.charAt(next++);
     }
 
     @Override
-    public int read(char cbuf[], int off, int len) throws IOException {
+    public int read(char[] cbuf, int off, int len) throws IOException {
       ensureOpen();
       if ((off < 0) || (off > cbuf.length) || (len < 0)
         || ((off + len) > cbuf.length) || ((off + len) < 0)) {
         throw new IndexOutOfBoundsException();
       } else if (len == 0) {
         return 0;
       }
-      if (next >= length)
+      if (next >= length) {
         return -1;
+      }
       int n = Math.min(length - next, len);
       str.getChars(next, next + n, cbuf, off);
       next += n;
@@ -149,8 +151,9 @@ public int read(char cbuf[], int off, int len) throws IOException {
     @Override
     public long skip(long ns) throws IOException {
       ensureOpen();
-      if (next >= length)
+      if (next >= length) {
         return 0;
+      }
       // Bound skip by beginning and end of the source
       long n = Math.min(length - next, ns);
       n = Math.max(-next, n);

sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java

@@ -89,8 +89,8 @@ public UnsafeExternalRowSorter(
       sparkEnv.conf().getInt("spark.shuffle.sort.initialBufferSize",
                              DEFAULT_INITIAL_SORT_BUFFER_SIZE),
       pageSizeBytes,
-      SparkEnv.get().conf().getLong("spark.shuffle.spill.numElementsForceSpillThreshold", UnsafeExternalSorter
-          .DEFAULT_NUM_ELEMENTS_FOR_SPILL_THRESHOLD),
+      SparkEnv.get().conf().getLong("spark.shuffle.spill.numElementsForceSpillThreshold",
+        UnsafeExternalSorter.DEFAULT_NUM_ELEMENTS_FOR_SPILL_THRESHOLD),
       canUseRadixSort
     );
   }

sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java

@@ -247,8 +247,8 @@ public UnsafeKVExternalSorter destructAndCreateExternalSorter() throws IOExcepti
       SparkEnv.get().blockManager(),
       SparkEnv.get().serializerManager(),
       map.getPageSizeBytes(),
-      SparkEnv.get().conf().getLong("spark.shuffle.spill.numElementsForceSpillThreshold", UnsafeExternalSorter
-          .DEFAULT_NUM_ELEMENTS_FOR_SPILL_THRESHOLD),
+      SparkEnv.get().conf().getLong("spark.shuffle.spill.numElementsForceSpillThreshold",
+        UnsafeExternalSorter.DEFAULT_NUM_ELEMENTS_FOR_SPILL_THRESHOLD),
       map);
   }
 }

sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeKVExternalSorter.java

@@ -57,7 +57,8 @@ public UnsafeKVExternalSorter(
       SerializerManager serializerManager,
       long pageSizeBytes,
       long numElementsForSpillThreshold) throws IOException {
-    this(keySchema, valueSchema, blockManager, serializerManager, pageSizeBytes, numElementsForSpillThreshold, null);
+    this(keySchema, valueSchema, blockManager, serializerManager, pageSizeBytes,
+      numElementsForSpillThreshold, null);
   }
 
   public UnsafeKVExternalSorter(