HBASE-23622 Reduced the number of Checkstyle violations in hbase-common

hbase-common/src/main/java/org/apache/hadoop/hbase/CellComparator.java

@@ -55,7 +55,7 @@ public int compare(Cell a, Cell b) {
    * @param a
    * @param b
    * @param ignoreSequenceid True if we are to compare the key portion only and ignore
-   * the sequenceid. Set to false to compare key and consider sequenceid.
+   *    the sequenceid. Set to false to compare key and consider sequenceid.
    * @return 0 if equal, -1 if a < b, and +1 if a > b.
    */
   public static int compare(final Cell a, final Cell b, boolean ignoreSequenceid) {

hbase-common/src/main/java/org/apache/hadoop/hbase/net/Address.java

@@ -26,7 +26,7 @@
  * An immutable type to hold a hostname and port combo, like an Endpoint
  * or java.net.InetSocketAddress (but without danger of our calling
  * resolve -- we do NOT want a resolve happening every time we want
- * to hold a hostname and port combo). This class is also <<Comparable>>.
+ * to hold a hostname and port combo). This class is also {@link Comparable}
  * <p>In implementation this class is a facade over Guava's {@link HostAndPort}.
  * We cannot have Guava classes in our API hence this Type.
  */
@@ -83,7 +83,10 @@ public int hashCode() {
   @Override
   public int compareTo(Address that) {
     int compare = this.getHostname().compareTo(that.getHostname());
-    if (compare != 0) return compare;
+    if (compare != 0) {
+      return compare;
+    }
+
     return this.getPort() - that.getPort();
   }
 }

hbase-common/src/main/java/org/apache/hadoop/hbase/trace/SpanReceiverHost.java

@@ -43,7 +43,7 @@ public class SpanReceiverHost {
   private boolean closed = false;
 
   @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="SE_BAD_FIELD")
-  private static enum SingletonHolder {
+  private enum SingletonHolder {
     INSTANCE;
     final Object lock = new Object();
     SpanReceiverHost host = null; // FindBugs: SE_BAD_FIELD
@@ -64,14 +64,13 @@ public static SpanReceiverHost getInstance(Configuration conf) {
   }
 
   SpanReceiverHost(Configuration conf) {
-    receivers = new HashSet<SpanReceiver>();
+    receivers = new HashSet<>();
     this.conf = conf;
   }
 
   /**
    * Reads the names of classes specified in the {@code hbase.trace.spanreceiver.classes} property
    * and instantiates and registers them with the Tracer.
-   *
    */
   public void loadSpanReceivers() {
     String[] receiverNames = conf.getStrings(SPAN_RECEIVERS_CONF_KEY);
@@ -98,7 +97,10 @@ public void loadSpanReceivers() {
    * Calls close() on all SpanReceivers created by this SpanReceiverHost.
    */
   public synchronized void closeReceivers() {
-    if (closed) return;
+    if (closed) {
+      return;
+    }
+
     closed = true;
     for (SpanReceiver rcvr : receivers) {
       try {

hbase-common/src/main/java/org/apache/hadoop/hbase/util/ByteRangeUtils.java

@@ -33,12 +33,16 @@
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
-public class ByteRangeUtils {
+public final class ByteRangeUtils {
+  private ByteRangeUtils() {
+  }
 
   public static int numEqualPrefixBytes(ByteRange left, ByteRange right, int rightInnerOffset) {
     int maxCompares = Math.min(left.getLength(), right.getLength() - rightInnerOffset);
-    final byte[] lbytes = left.getBytes(), rbytes = right.getBytes();
-    final int loffset = left.getOffset(), roffset = right.getOffset();
+    final byte[] lbytes = left.getBytes();
+    final byte[] rbytes = right.getBytes();
+    final int loffset = left.getOffset();
+    final int roffset = right.getOffset();
     for (int i = 0; i < maxCompares; ++i) {
       if (lbytes[loffset + i] != rbytes[roffset + rightInnerOffset + i]) {
         return i;
@@ -49,7 +53,7 @@ public static int numEqualPrefixBytes(ByteRange left, ByteRange right, int right
 
   public static ArrayList<byte[]> copyToNewArrays(Collection<ByteRange> ranges) {
     if (ranges == null) {
-      return new ArrayList<byte[]>(0);
+      return new ArrayList<>(0);
     }
     ArrayList<byte[]> arrays = Lists.newArrayListWithCapacity(ranges.size());
     for (ByteRange range : ranges) {
@@ -60,7 +64,7 @@ public static ArrayList<byte[]> copyToNewArrays(Collection<ByteRange> ranges) {
 
   public static ArrayList<ByteRange> fromArrays(Collection<byte[]> arrays) {
     if (arrays == null) {
-      return new ArrayList<ByteRange>(0);
+      return new ArrayList<>(0);
     }
     ArrayList<ByteRange> ranges = Lists.newArrayListWithCapacity(arrays.size());
     for (byte[] array : arrays) {
@@ -78,5 +82,4 @@ public static void write(OutputStream os, ByteRange byteRange, int byteRangeInne
     os.write(byteRange.getBytes(), byteRange.getOffset() + byteRangeInnerOffset,
       byteRange.getLength() - byteRangeInnerOffset);
   }
-
 }

hbase-common/src/main/java/org/apache/hadoop/hbase/util/CommonFSUtils.java

@@ -137,8 +137,7 @@ public static boolean isMatchingTail(final Path pathToSearch, final Path pathTai
    * @return True if deleted <code>dir</code>
    * @throws IOException e
    */
-  public static boolean deleteDirectory(final FileSystem fs, final Path dir)
-  throws IOException {
+  public static boolean deleteDirectory(final FileSystem fs, final Path dir) throws IOException {
     return fs.exists(dir) && fs.delete(dir, true);
   }
 
@@ -157,7 +156,7 @@ public static long getDefaultBlockSize(final FileSystem fs, final Path path) thr
     Method m = null;
     Class<? extends FileSystem> cls = fs.getClass();
     try {
-      m = cls.getMethod("getDefaultBlockSize", new Class<?>[] { Path.class });
+      m = cls.getMethod("getDefaultBlockSize", Path.class);
     } catch (NoSuchMethodException e) {
       LOG.info("FileSystem doesn't support getDefaultBlockSize");
     } catch (SecurityException e) {
@@ -192,7 +191,7 @@ public static short getDefaultReplication(final FileSystem fs, final Path path)
     Method m = null;
     Class<? extends FileSystem> cls = fs.getClass();
     try {
-      m = cls.getMethod("getDefaultReplication", new Class<?>[] { Path.class });
+      m = cls.getMethod("getDefaultReplication", Path.class);
     } catch (NoSuchMethodException e) {
       LOG.info("FileSystem doesn't support getDefaultReplication");
     } catch (SecurityException e) {
@@ -358,11 +357,11 @@ public static Path getRootDir(final Configuration c) throws IOException {
     return p.makeQualified(fs);
   }
 
-  public static void setRootDir(final Configuration c, final Path root) throws IOException {
+  public static void setRootDir(final Configuration c, final Path root) {
     c.set(HConstants.HBASE_DIR, root.toString());
   }
 
-  public static void setFsDefault(final Configuration c, final Path root) throws IOException {
+  public static void setFsDefault(final Configuration c, final Path root) {
     c.set("fs.defaultFS", root.toString());    // for hadoop 0.21+
   }
 
@@ -387,7 +386,7 @@ public static Path getWALRootDir(final Configuration c) throws IOException {
   }
 
   @VisibleForTesting
-  public static void setWALRootDir(final Configuration c, final Path root) throws IOException {
+  public static void setWALRootDir(final Configuration c, final Path root) {
     c.set(HBASE_WAL_DIR, root.toString());
   }
 
@@ -481,8 +480,7 @@ public static void setStoragePolicy(final FileSystem fs, final Configuration con
     setStoragePolicy(fs, path, storagePolicy);
   }
 
-  private static final Map<FileSystem, Boolean> warningMap =
-      new ConcurrentHashMap<FileSystem, Boolean>();
+  private static final Map<FileSystem, Boolean> warningMap = new ConcurrentHashMap<>();
 
   /**
    * Sets storage policy for given path.
@@ -560,8 +558,7 @@ private static void invokeSetStoragePolicy(final FileSystem fs, final Path path,
     Method m = null;
     Exception toThrow = null;
     try {
-      m = fs.getClass().getDeclaredMethod("setStoragePolicy",
-        new Class<?>[] { Path.class, String.class });
+      m = fs.getClass().getDeclaredMethod("setStoragePolicy", Path.class, String.class);
       m.setAccessible(true);
     } catch (NoSuchMethodException e) {
       toThrow = e;
@@ -621,7 +618,6 @@ private static void invokeSetStoragePolicy(final FileSystem fs, final Path path,
     }
   }
 
-
   /**
    * @param conf must not be null
    * @return True if this filesystem whose scheme is 'hdfs'.
@@ -647,8 +643,7 @@ public static boolean isRecoveredEdits(Path path) {
    * @return Returns the filesystem of the hbase rootdir.
    * @throws IOException from underlying FileSystem
    */
-  public static FileSystem getCurrentFileSystem(Configuration conf)
-  throws IOException {
+  public static FileSystem getCurrentFileSystem(Configuration conf) throws IOException {
     return getRootDir(conf).getFileSystem(conf);
   }
 
@@ -666,7 +661,7 @@ public static FileSystem getCurrentFileSystem(Configuration conf)
    * @param filter path filter
    * @return null if dir is empty or doesn't exist, otherwise FileStatus array
    */
-  public static FileStatus [] listStatus(final FileSystem fs,
+  public static FileStatus[] listStatus(final FileSystem fs,
       final Path dir, final PathFilter filter) throws IOException {
     FileStatus [] status = null;
     try {
@@ -753,21 +748,21 @@ public static boolean isExists(final FileSystem fs, final Path path) throws IOEx
    * Log the current state of the filesystem from a certain root directory
    * @param fs filesystem to investigate
    * @param root root file/directory to start logging from
-   * @param LOG log to output information
+   * @param log log to output information
    * @throws IOException if an unexpected exception occurs
    */
-  public static void logFileSystemState(final FileSystem fs, final Path root, Log LOG)
+  public static void logFileSystemState(final FileSystem fs, final Path root, Log log)
       throws IOException {
-    LOG.debug("Current file system:");
-    logFSTree(LOG, fs, root, "|-");
+    log.debug("Current file system:");
+    logFSTree(log, fs, root, "|-");
   }
 
   /**
    * Recursive helper to log the state of the FS
    *
    * @see #logFileSystemState(FileSystem, Path, Log)
    */
-  private static void logFSTree(Log LOG, final FileSystem fs, final Path root, String prefix)
+  private static void logFSTree(Log log, final FileSystem fs, final Path root, String prefix)
       throws IOException {
     FileStatus[] files = listStatus(fs, root, null);
     if (files == null) {
@@ -776,10 +771,10 @@ private static void logFSTree(Log LOG, final FileSystem fs, final Path root, Str
 
     for (FileStatus file : files) {
       if (file.isDirectory()) {
-        LOG.debug(prefix + file.getPath().getName() + "/");
-        logFSTree(LOG, fs, file.getPath(), prefix + "---");
+        log.debug(prefix + file.getPath().getName() + "/");
+        logFSTree(log, fs, file.getPath(), prefix + "---");
       } else {
-        LOG.debug(prefix + file.getPath().getName());
+        log.debug(prefix + file.getPath().getName());
       }
     }
   }
@@ -791,25 +786,6 @@ public static boolean renameAndSetModifyTime(final FileSystem fs, final Path src
     return fs.rename(src, dest);
   }
 
-  /**
-   * Do our short circuit read setup.
-   * Checks buffer size to use and whether to do checksumming in hbase or hdfs.
-   * @param conf must not be null
-   */
-  public static void setupShortCircuitRead(final Configuration conf) {
-    // Check that the user has not set the "dfs.client.read.shortcircuit.skip.checksum" property.
-    boolean shortCircuitSkipChecksum =
-      conf.getBoolean("dfs.client.read.shortcircuit.skip.checksum", false);
-    boolean useHBaseChecksum = conf.getBoolean(HConstants.HBASE_CHECKSUM_VERIFICATION, true);
-    if (shortCircuitSkipChecksum) {
-      LOG.warn("Configuration \"dfs.client.read.shortcircuit.skip.checksum\" should not " +
-        "be set to true." + (useHBaseChecksum ? " HBase checksum doesn't require " +
-        "it, see https://issues.apache.org/jira/browse/HBASE-6868." : ""));
-      assert !shortCircuitSkipChecksum; //this will fail if assertions are on
-    }
-    checkShortCircuitReadBufferSize(conf);
-  }
-
   /**
    * Check if short circuit read buffer size is set and if not, set it to hbase value.
    * @param conf must not be null
@@ -912,5 +888,4 @@ public StreamLacksCapabilityException(String message) {
       super(message);
     }
   }
-
 }

hbase-common/src/main/java/org/apache/hadoop/hbase/util/ConcatenatedLists.java

@@ -79,7 +79,10 @@ public T next() {
       if (!components.isEmpty()) {
         this.nextWasCalled = true;
         List<T> src = components.get(currentComponent);
-        if (++indexWithinComponent < src.size()) return src.get(indexWithinComponent);
+        if (++indexWithinComponent < src.size()) {
+          return src.get(indexWithinComponent);
+        }
+
         if (++currentComponent < components.size()) {
           indexWithinComponent = 0;
           src = components.get(currentComponent);

hbase-common/src/main/java/org/apache/hadoop/hbase/util/Order.java

@@ -29,22 +29,31 @@
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
 public enum Order {
-
   ASCENDING {
     @Override
-    public int cmp(int cmp) { /* noop */ return cmp; }
+    public int cmp(int cmp) {
+      /* noop */ return cmp;
+    }
 
     @Override
-    public byte apply(byte val) { /* noop */ return val; }
+    public byte apply(byte val) {
+      /* noop */ return val;
+    }
 
     @Override
-    public void apply(byte[] val) { /* noop */ }
+    public void apply(byte[] val) {
+      /* noop */
+    }
 
     @Override
-    public void apply(byte[] val, int offset, int length) { /* noop */ }
+    public void apply(byte[] val, int offset, int length) {
+      /* noop */
+    }
 
     @Override
-    public String toString() { return "ASCENDING"; }
+    public String toString() {
+      return "ASCENDING";
+    }
   },
 
   DESCENDING {
@@ -55,23 +64,33 @@ public void apply(byte[] val, int offset, int length) { /* noop */ }
     private static final byte MASK = (byte) 0xff;
 
     @Override
-    public int cmp(int cmp) { return -1 * cmp; }
+    public int cmp(int cmp) {
+      return -1 * cmp;
+    }
 
     @Override
-    public byte apply(byte val) { return (byte) (val ^ MASK); }
+    public byte apply(byte val) {
+      return (byte) (val ^ MASK);
+    }
 
     @Override
     public void apply(byte[] val) {
-      for (int i = 0; i < val.length; i++) { val[i] ^= MASK; }
+      for (int i = 0; i < val.length; i++) {
+        val[i] ^= MASK;
+      }
     }
 
     @Override
     public void apply(byte[] val, int offset, int length) {
-      for (int i = 0; i < length; i++) { val[offset + i] ^= MASK; }
+      for (int i = 0; i < length; i++) {
+        val[offset + i] ^= MASK;
+      }
     }
 
     @Override
-    public String toString() { return "DESCENDING"; }
+    public String toString() {
+      return "DESCENDING";
+    }
   };
 
   /**