HADOOP-16830. Checkstyles and findbugs

Change-Id: I5f64704a82a196fd8ff66cbde10d4970722e1fd7

Author: steveloughran

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/IOStatisticsSnapshot.java

@@ -111,7 +111,7 @@ public IOStatisticsSnapshot(IOStatistics source) {
   /**
    * Create the maps.
    */
-  private void createMaps() {
+  private synchronized void createMaps() {
     counters = new ConcurrentHashMap<>();
     gauges = new ConcurrentHashMap<>();
     minimums = new ConcurrentHashMap<>();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/StoreStatisticNames.java

@@ -253,11 +253,12 @@ public final class StoreStatisticNames {
 
 
   /**
-   * The name of the statistic collected for executor aquisition if
+   * The name of the statistic collected for executor acquisition if
    * a duration tracker factory is passed in to the constructor.
    * {@value}.
    */
-  public static String ACTION_EXECUTOR_ACQUIRED = "action_executor_acquired";
+  public static final String ACTION_EXECUTOR_ACQUIRED =
+      "action_executor_acquired";
 
   /**
    * An HTTP HEAD request was made: {@value}.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsBinding.java

@@ -21,7 +21,6 @@
 import java.io.Serializable;
 import java.util.Iterator;
 import java.util.Map;
-import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.BiFunction;

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsStoreImpl.java

@@ -257,11 +257,11 @@ public synchronized boolean aggregate(
     Map<String, Long> sourceCounters = source.counters();
     counterMap.entrySet().
         forEach(e -> {
-      Long sourceValue = lookupQuietly(sourceCounters, e.getKey());
-      if (sourceValue != null) {
-        e.getValue().addAndGet(sourceValue);
-      }
-    });
+          Long sourceValue = lookupQuietly(sourceCounters, e.getKey());
+          if (sourceValue != null) {
+            e.getValue().addAndGet(sourceValue);
+          }
+        });
     // gauge: add positive values only
     Map<String, Long> sourceGauges = source.gauges();
     gaugeMap.entrySet().forEach(e -> {

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/StubDurationTrackerFactory.java

@@ -25,7 +25,8 @@
  * This is a stub factory which always returns no-op duration
  * trackers. Allows for code to always be handed a factory.
  */
-public final class StubDurationTrackerFactory implements DurationTrackerFactory {
+public final class StubDurationTrackerFactory
+    implements DurationTrackerFactory {
 
   /**
    * Single instance.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/functional/RemoteIterators.java

@@ -568,7 +568,7 @@ private MaybeClose(Object o) {
     }
 
     /**
-     * Construct -close the object if it is closeable and close==true
+     * Construct -close the object if it is closeable and close==true.
      * @param o object to close.
      * @param close should close?
      */

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/contract/AbstractContractStreamIOStatisticsTest.java

@@ -31,7 +31,6 @@
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.statistics.IOStatistics;
-import org.apache.hadoop.fs.statistics.IOStatisticsLogging;
 
 import static org.apache.hadoop.fs.contract.ContractTestUtils.dataset;
 import static org.apache.hadoop.fs.statistics.IOStatisticAssertions.extractStatistics;

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/statistics/TestIOStatisticsSnapshot.java

@@ -115,6 +115,16 @@ public void testJsonRoundTrip() throws Throwable {
     String json = serializer.toJson(snapshot);
     LOG.info("serialized form\n{}", json);
     IOStatisticsSnapshot deser = serializer.fromJson(json);
+    verifyDeserializedInstance(deser);
+  }
+
+  /**
+   * Verify the deserialized instance's data
+   * matches the expected values.
+   * @param deser deserialized vlaue.
+   */
+  public void verifyDeserializedInstance(
+      final IOStatistics deser) {
     LOG.info("deserialized {}", deser);
     verifyCounterStatisticValue(deser, "c1", 0L);
     verifyGaugeStatisticValue(deser, "g1", 1L);
@@ -127,7 +137,9 @@ public void testJsonRoundTrip() throws Throwable {
 
   @Test
   public void testJavaRoundTrip() throws Throwable {
-    IOStatisticsSnapshot deser = (IOStatisticsSnapshot) IOStatisticAssertions.javaRoundTrip(snapshot);
+    verifyDeserializedInstance(
+        IOStatisticAssertions.javaRoundTrip(
+            snapshot));
 
 
   }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/util/functional/TestRemoteIterators.java

@@ -54,27 +54,27 @@ public class TestRemoteIterators extends AbstractHadoopTestBase {
   private static final Logger LOG = LoggerFactory.getLogger(
       TestRemoteIterators.class);
 
-  private static final String[] data = {"a", "b", "c"};
+  private static final String[] DATA = {"a", "b", "c"};
 
   /** Counter for lambda-expressions. */
   private int counter;
 
   @Test
   public void testIterateArray() throws Throwable {
-    verifySize(remoteIteratorFromArray(data), data.length,
+    verifySize(remoteIteratorFromArray(DATA), DATA.length,
         (s) -> LOG.info(s));
   }
 
   @Test
   public void testIterateArrayMapped() throws Throwable {
     verifySize(
         mappingRemoteIterator(
-            remoteIteratorFromArray(data),
+            remoteIteratorFromArray(DATA),
             (d) -> {
               counter += d.length();
               return d;
             }),
-        data.length,
+        DATA.length,
         this::log);
     assertCounterValue(3);
   }
@@ -335,7 +335,7 @@ public IOStatistics getIOStatistics() {
   /**
    * Iterator which counts down.
    */
-  private static class CountdownRemoteIterator extends CloseCounter
+  private static final class CountdownRemoteIterator extends CloseCounter
       implements RemoteIterator<Integer> {
 
     private int limit;
@@ -365,7 +365,7 @@ public String toString() {
   /**
    * Iterator which counts down.
    */
-  private static class CountdownIterator extends CloseCounter
+  private static final class CountdownIterator extends CloseCounter
       implements Iterator<Integer> {
 
     private int limit;
@@ -396,7 +396,7 @@ public String toString() {
    * Iterable for countdown iterators.
    * Once closed, calls to iterator() raise an exception.
    */
-  private static class CountdownIterable extends CloseCounter
+  private static final class CountdownIterable extends CloseCounter
       implements Iterable<Integer> {
 
     private int limit;