HDFS-7515. Fix new findbugs warnings in hadoop-hdfs. Contributed by Haohui Mai.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -572,6 +572,8 @@ Release 2.7.0 - UNRELEASED
     HDFS-7475. Make TestLazyPersistFiles#testLazyPersistBlocksAreSaved
     deterministic. (Xiaoyu Yao via Arpit Agarwal)
 
+    HDFS-7515. Fix new findbugs warnings in hadoop-hdfs. (wheat9)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/BlockReaderFactory.java

@@ -668,7 +668,6 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
       Peer peer = null;
       try {
         curPeer = nextTcpPeer();
-        if (curPeer == null) break;
         if (curPeer.fromCache) remainingCacheTries--;
         peer = curPeer.peer;
         blockReader = getRemoteBlockReader(peer);
@@ -699,7 +698,6 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
         }
       }
     }
-    return null;
   }
 
   public static class BlockReaderPeer {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java

@@ -39,6 +39,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.apache.hadoop.HadoopIllegalArgumentException;
@@ -241,8 +242,6 @@ public class DFSOutputStream extends FSOutputSummer
     /**
      * Create a new packet.
      * 
-     * @param pktSize maximum size of the packet, 
-     *                including checksum data and actual data.
      * @param chunksPerPkt maximum number of chunks per packet.
      * @param offsetInBlock offset in bytes into the HDFS block.
      */
@@ -405,7 +404,8 @@ public class DFSOutputStream extends FSOutputSummer
     private String[] favoredNodes;
     volatile boolean hasError = false;
     volatile int errorIndex = -1;
-    volatile int restartingNodeIndex = -1; // Restarting node index
+    // Restarting node index
+    AtomicInteger restartingNodeIndex = new AtomicInteger(-1);
     private long restartDeadline = 0; // Deadline of DN restart
     private BlockConstructionStage stage;  // block construction stage
     private long bytesSent = 0; // number of bytes that've been sent
@@ -556,7 +556,7 @@ public class DFSOutputStream extends FSOutputSummer
         try {
           // process datanode IO errors if any
           boolean doSleep = false;
-          if (hasError && (errorIndex >= 0 || restartingNodeIndex >= 0)) {
+          if (hasError && (errorIndex >= 0 || restartingNodeIndex.get() >= 0)) {
             doSleep = processDatanodeError();
           }
 
@@ -699,7 +699,7 @@ public class DFSOutputStream extends FSOutputSummer
           }
         } catch (Throwable e) {
           // Log warning if there was a real error.
-          if (restartingNodeIndex == -1) {
+          if (restartingNodeIndex.get() == -1) {
             DFSClient.LOG.warn("DataStreamer Exception", e);
           }
           if (e instanceof IOException) {
@@ -708,7 +708,7 @@ public class DFSOutputStream extends FSOutputSummer
             setLastException(new IOException("DataStreamer Exception: ",e));
           }
           hasError = true;
-          if (errorIndex == -1 && restartingNodeIndex == -1) {
+          if (errorIndex == -1 && restartingNodeIndex.get() == -1) {
             // Not a datanode issue
             streamerClosed = true;
           }
@@ -806,7 +806,7 @@ public class DFSOutputStream extends FSOutputSummer
 
     /** Set the restarting node index. Called by responder */
     synchronized void setRestartingNodeIndex(int idx) {
-      restartingNodeIndex = idx;
+      restartingNodeIndex.set(idx);
       // If the data streamer has already set the primary node
       // bad, clear it. It is likely that the write failed due to
       // the DN shutdown. Even if it was a real failure, the pipeline
@@ -821,7 +821,7 @@ public class DFSOutputStream extends FSOutputSummer
      */
     synchronized void tryMarkPrimaryDatanodeFailed() {
       // There should be no existing error and no ongoing restart.
-      if ((errorIndex == -1) && (restartingNodeIndex == -1)) {
+      if ((errorIndex == -1) && (restartingNodeIndex.get() == -1)) {
         errorIndex = 0;
       }
     }
@@ -962,7 +962,7 @@ public class DFSOutputStream extends FSOutputSummer
               synchronized (dataQueue) {
                 dataQueue.notifyAll();
               }
-              if (restartingNodeIndex == -1) {
+              if (restartingNodeIndex.get() == -1) {
                 DFSClient.LOG.warn("DFSOutputStream ResponseProcessor exception "
                      + " for block " + block, e);
               }
@@ -1186,7 +1186,7 @@ public class DFSOutputStream extends FSOutputSummer
         // Sleep before reconnect if a dn is restarting.
         // This process will be repeated until the deadline or the datanode
         // starts back up.
-        if (restartingNodeIndex >= 0) {
+        if (restartingNodeIndex.get() >= 0) {
           // 4 seconds or the configured deadline period, whichever is shorter.
           // This is the retry interval and recovery will be retried in this
           // interval until timeout or success.
@@ -1196,7 +1196,7 @@ public class DFSOutputStream extends FSOutputSummer
             Thread.sleep(delay);
           } catch (InterruptedException ie) {
             lastException.set(new IOException("Interrupted while waiting for " +
-                "datanode to restart. " + nodes[restartingNodeIndex]));
+                "datanode to restart. " + nodes[restartingNodeIndex.get()]));
             streamerClosed = true;
             return false;
           }
@@ -1237,21 +1237,21 @@ public class DFSOutputStream extends FSOutputSummer
           setPipeline(newnodes, newStorageTypes, newStorageIDs);
 
           // Just took care of a node error while waiting for a node restart
-          if (restartingNodeIndex >= 0) {
+          if (restartingNodeIndex.get() >= 0) {
             // If the error came from a node further away than the restarting
             // node, the restart must have been complete.
-            if (errorIndex > restartingNodeIndex) {
-              restartingNodeIndex = -1;
-            } else if (errorIndex < restartingNodeIndex) {
+            if (errorIndex > restartingNodeIndex.get()) {
+              restartingNodeIndex.set(-1);
+            } else if (errorIndex < restartingNodeIndex.get()) {
               // the node index has shifted.
-              restartingNodeIndex--;
+              restartingNodeIndex.decrementAndGet();
             } else {
               // this shouldn't happen...
               assert false;
             }
           }
 
-          if (restartingNodeIndex == -1) {
+          if (restartingNodeIndex.get() == -1) {
             hasError = false;
           }
           lastException.set(null);
@@ -1293,10 +1293,10 @@ public class DFSOutputStream extends FSOutputSummer
           success = createBlockOutputStream(nodes, storageTypes, newGS, isRecovery);
         }
 
-        if (restartingNodeIndex >= 0) {
+        if (restartingNodeIndex.get() >= 0) {
           assert hasError == true;
           // check errorIndex set above
-          if (errorIndex == restartingNodeIndex) {
+          if (errorIndex == restartingNodeIndex.get()) {
             // ignore, if came from the restarting node
             errorIndex = -1;
           }
@@ -1306,8 +1306,8 @@ public class DFSOutputStream extends FSOutputSummer
           }
           // expired. declare the restarting node dead
           restartDeadline = 0;
-          int expiredNodeIndex = restartingNodeIndex;
-          restartingNodeIndex = -1;
+          int expiredNodeIndex = restartingNodeIndex.get();
+          restartingNodeIndex.set(-1);
           DFSClient.LOG.warn("Datanode did not restart in time: " +
               nodes[expiredNodeIndex]);
           // Mark the restarting node as failed. If there is any other failed
@@ -1459,7 +1459,7 @@ public class DFSOutputStream extends FSOutputSummer
           // from the local datanode. Thus it is safe to treat this as a
           // regular node error.
           if (PipelineAck.isRestartOOBStatus(pipelineStatus) &&
-            restartingNodeIndex == -1) {
+            restartingNodeIndex.get() == -1) {
             checkRestart = true;
             throw new IOException("A datanode is restarting.");
           }
@@ -1476,10 +1476,10 @@ public class DFSOutputStream extends FSOutputSummer
           assert null == blockStream : "Previous blockStream unclosed";
           blockStream = out;
           result =  true; // success
-          restartingNodeIndex = -1;
+          restartingNodeIndex.set(-1);
           hasError = false;
         } catch (IOException ie) {
-          if (restartingNodeIndex == -1) {
+          if (restartingNodeIndex.get() == -1) {
             DFSClient.LOG.info("Exception in createBlockOutputStream", ie);
           }
           if (ie instanceof InvalidEncryptionKeyException && refetchEncryptionKey > 0) {
@@ -1511,10 +1511,10 @@ public class DFSOutputStream extends FSOutputSummer
           if (checkRestart && shouldWaitForRestart(errorIndex)) {
             restartDeadline = dfsClient.getConf().datanodeRestartTimeout +
                 Time.now();
-            restartingNodeIndex = errorIndex;
+            restartingNodeIndex.set(errorIndex);
             errorIndex = -1;
             DFSClient.LOG.info("Waiting for the datanode to be restarted: " +
-                nodes[restartingNodeIndex]);
+                nodes[restartingNodeIndex.get()]);
           }
           hasError = true;
           setLastException(ie);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/qjournal/server/JournalNode.java

@@ -233,6 +233,7 @@ public class JournalNode implements Tool, Configurable, JournalNodeMXBean {
     Preconditions.checkArgument(jid != null &&
         !jid.isEmpty(),
         "bad journal identifier: %s", jid);
+    assert jid != null;
     return new File(new File(dir), jid);
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/Storage.java

@@ -727,7 +727,7 @@ public abstract class Storage extends StorageInfo {
         file.close();
         throw e;
       }
-      if (res != null && !deletionHookAdded) {
+      if (!deletionHookAdded) {
         // If the file existed prior to our startup, we didn't
         // call deleteOnExit above. But since we successfully locked
         // the dir, we can take care of cleaning it up.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockReceiver.java

@@ -29,6 +29,8 @@ import java.io.FileOutputStream;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.LinkedList;
@@ -836,9 +838,8 @@ class BlockReceiver implements Closeable {
               LOG.warn("Failed to delete restart meta file: " +
                   restartMeta.getPath());
             }
-            FileWriter out = null;
-            try {
-              out = new FileWriter(restartMeta);
+            try (Writer out = new OutputStreamWriter(
+                new FileOutputStream(restartMeta), "UTF-8")) {
               // write out the current time.
               out.write(Long.toString(Time.now() + restartBudget));
               out.flush();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -580,7 +580,8 @@ public class DataNode extends ReconfigurableBase
           try {
             IOException ioe = ioExceptionFuture.get();
             if (ioe != null) {
-              errorMessageBuilder.append(String.format("FAILED TO ADD: %s: %s\n",
+              errorMessageBuilder.append(
+                  String.format("FAILED TO ADD: %s: %s%n",
                   volume, ioe.getMessage()));
               LOG.error("Failed to add volume: " + volume, ioe);
             } else {
@@ -588,8 +589,9 @@ public class DataNode extends ReconfigurableBase
               LOG.info("Successfully added volume: " + volume);
             }
           } catch (Exception e) {
-            errorMessageBuilder.append(String.format("FAILED to ADD: %s: %s\n",
-                volume, e.getMessage()));
+            errorMessageBuilder.append(
+                String.format("FAILED to ADD: %s: %s%n", volume,
+                              e.toString()));
           }
         }
       }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataStorage.java

@@ -425,7 +425,7 @@ public class DataStorage extends Storage {
           LOG.warn(String.format(
             "I/O error attempting to unlock storage directory %s.",
             sd.getRoot()), e);
-          errorMsgBuilder.append(String.format("Failed to remove %s: %s\n",
+          errorMsgBuilder.append(String.format("Failed to remove %s: %s%n",
               sd.getRoot(), e.getMessage()));
         }
       }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/BlockPoolSlice.java

@@ -22,10 +22,13 @@ import java.io.DataInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStreamWriter;
 import java.io.RandomAccessFile;
+import java.io.Writer;
 import java.util.Scanner;
 
 import org.apache.commons.io.FileUtils;
@@ -186,7 +189,7 @@ class BlockPoolSlice {
     Scanner sc;
 
     try {
-      sc = new Scanner(new File(currentDir, DU_CACHE_FILE));
+      sc = new Scanner(new File(currentDir, DU_CACHE_FILE), "UTF-8");
     } catch (FileNotFoundException fnfe) {
       return -1;
     }
@@ -227,23 +230,18 @@ class BlockPoolSlice {
         outFile.getParent());
     }
 
-    FileWriter out = null;
     try {
       long used = getDfsUsed();
-      if (used > 0) {
-        out = new FileWriter(outFile);
+      try (Writer out = new OutputStreamWriter(
+          new FileOutputStream(outFile), "UTF-8")) {
         // mtime is written last, so that truncated writes won't be valid.
         out.write(Long.toString(used) + " " + Long.toString(Time.now()));
         out.flush();
-        out.close();
-        out = null;
       }
     } catch (IOException ioe) {
       // If write failed, the volume might be bad. Since the cache file is
       // not critical, log the error and continue.
       FsDatasetImpl.LOG.warn("Failed to write dfsUsed to " + outFile, ioe);
-    } finally {
-      IOUtils.cleanup(null, out);
     }
   }
 
@@ -447,7 +445,7 @@ class BlockPoolSlice {
             File.pathSeparator + "." + file.getName() + ".restart");
         Scanner sc = null;
         try {
-          sc = new Scanner(restartMeta);
+          sc = new Scanner(restartMeta, "UTF-8");
           // The restart meta file exists
           if (sc.hasNextLong() && (sc.nextLong() > Time.now())) {
             // It didn't expire. Load the replica as a RBW.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

@@ -769,7 +769,6 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     final byte[] crcs = new byte[checksum.getChecksumSize(data.length)];
 
     DataOutputStream metaOut = null;
-    InputStream dataIn = null;
     try {
       File parentFile = dstMeta.getParentFile();
       if (parentFile != null) {
@@ -782,22 +781,23 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
           new FileOutputStream(dstMeta), HdfsConstants.SMALL_BUFFER_SIZE));
       BlockMetadataHeader.writeHeader(metaOut, checksum);
 
-      dataIn = isNativeIOAvailable ?
+      int offset = 0;
+      try (InputStream dataIn = isNativeIOAvailable ?
           NativeIO.getShareDeleteFileInputStream(blockFile) :
-          new FileInputStream(blockFile);
+          new FileInputStream(blockFile)) {
 
-      int offset = 0;
-      for(int n; (n = dataIn.read(data, offset, data.length - offset)) != -1; ) {
-        if (n > 0) {
-          n += offset;
-          offset = n % checksum.getBytesPerChecksum();
-          final int length = n - offset;
+        for (int n; (n = dataIn.read(data, offset, data.length - offset)) != -1; ) {
+          if (n > 0) {
+            n += offset;
+            offset = n % checksum.getBytesPerChecksum();
+            final int length = n - offset;
 
-          if (length > 0) {
-            checksum.calculateChunkedSums(data, 0, length, crcs, 0);
-            metaOut.write(crcs, 0, checksum.getChecksumSize(length));
+            if (length > 0) {
+              checksum.calculateChunkedSums(data, 0, length, crcs, 0);
+              metaOut.write(crcs, 0, checksum.getChecksumSize(length));
 
-            System.arraycopy(data, length, data, 0, offset);
+              System.arraycopy(data, length, data, 0, offset);
+            }
           }
         }
       }
@@ -806,7 +806,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
       checksum.calculateChunkedSums(data, 0, offset, crcs, 0);
       metaOut.write(crcs, 0, 4);
     } finally {
-      IOUtils.cleanup(LOG, dataIn, metaOut);
+      IOUtils.cleanup(LOG, metaOut);
     }
   }
 
@@ -1599,11 +1599,6 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
         }
         f = info.getBlockFile();
         v = (FsVolumeImpl)info.getVolume();
-        if (f == null) {
-          errors.add("Failed to delete replica " + invalidBlks[i]
-              +  ": File not found, volume=" + v);
-          continue;
-        }
         if (v == null) {
           errors.add("Failed to delete replica " + invalidBlks[i]
               +  ". No volume for this replica, file=" + f);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/ExceptionHandler.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.datanode.web.webhdfs;
 
+import com.google.common.base.Charsets;
 import com.sun.jersey.api.ParamException;
 import com.sun.jersey.api.container.ContainerException;
 import io.netty.buffer.Unpooled;
@@ -39,7 +40,7 @@ import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
 import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
 import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
-import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.APPLICATION_JSON;
+import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.APPLICATION_JSON_UTF8;
 
 class ExceptionHandler {
   static Log LOG = WebHdfsHandler.LOG;
@@ -82,11 +83,11 @@ class ExceptionHandler {
       s = INTERNAL_SERVER_ERROR;
     }
 
-    final byte[] js = JsonUtil.toJsonString(e).getBytes();
+    final byte[] js = JsonUtil.toJsonString(e).getBytes(Charsets.UTF_8);
     DefaultFullHttpResponse resp =
       new DefaultFullHttpResponse(HTTP_1_1, s, Unpooled.wrappedBuffer(js));
 
-    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON);
+    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
     resp.headers().set(CONTENT_LENGTH, js.length);
     return resp;
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java

@@ -29,6 +29,7 @@ import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.QueryStringDecoder;
 import io.netty.handler.stream.ChunkedStream;
+import org.apache.commons.io.Charsets;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -77,7 +78,8 @@ public class WebHdfsHandler extends SimpleChannelInboundHandler<HttpRequest> {
   public static final int WEBHDFS_PREFIX_LENGTH = WEBHDFS_PREFIX.length();
   public static final String APPLICATION_OCTET_STREAM =
     "application/octet-stream";
-  public static final String APPLICATION_JSON = "application/json";
+  public static final String APPLICATION_JSON_UTF8 =
+      "application/json; charset=utf-8";
 
   private final Configuration conf;
   private final Configuration confForCreate;
@@ -224,11 +226,11 @@ public class WebHdfsHandler extends SimpleChannelInboundHandler<HttpRequest> {
     } finally {
       IOUtils.cleanup(LOG, dfsclient);
     }
-    final byte[] js = JsonUtil.toJsonString(checksum).getBytes();
+    final byte[] js = JsonUtil.toJsonString(checksum).getBytes(Charsets.UTF_8);
     DefaultFullHttpResponse resp =
       new DefaultFullHttpResponse(HTTP_1_1, OK, Unpooled.wrappedBuffer(js));
 
-    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON);
+    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
     resp.headers().set(CONTENT_LENGTH, js.length);
     resp.headers().set(CONNECTION, CLOSE);
     ctx.writeAndFlush(resp).addListener(ChannelFutureListener.CLOSE);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/mover/Mover.java

@@ -48,8 +48,10 @@ import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;
 
 import java.io.BufferedReader;
+import java.io.FileInputStream;
 import java.io.FileReader;
 import java.io.IOException;
+import java.io.InputStreamReader;
 import java.net.URI;
 import java.text.DateFormat;
 import java.util.*;
@@ -579,7 +581,8 @@ public class Mover {
 
     private static String[] readPathFile(String file) throws IOException {
       List<String> list = Lists.newArrayList();
-      BufferedReader reader = new BufferedReader(new FileReader(file));
+      BufferedReader reader = new BufferedReader(
+          new InputStreamReader(new FileInputStream(file), "UTF-8"));
       try {
         String line;
         while ((line = reader.readLine()) != null) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirRenameOp.java

@@ -433,7 +433,6 @@ class FSDirRenameOp {
         } else {
           fsd.addLastINodeNoQuotaCheck(dstIIP, removedDst);
         }
-        assert removedDst != null;
         if (removedDst.isReference()) {
           final INodeReference removedDstRef = removedDst.asReference();
           final INodeReference.WithCount wc = (INodeReference.WithCount)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirStatAndListingOp.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.hdfs.server.namenode;
 
 import com.google.common.base.Preconditions;
+import org.apache.commons.io.Charsets;
 import org.apache.hadoop.fs.ContentSummary;
 import org.apache.hadoop.fs.DirectoryListingStartAfterNotFoundException;
 import org.apache.hadoop.fs.FileEncryptionInfo;
@@ -50,7 +51,7 @@ class FSDirStatAndListingOp {
     FSPermissionChecker pc = fsd.getPermissionChecker();
     byte[][] pathComponents = FSDirectory
         .getPathComponentsForReservedPath(srcArg);
-    final String startAfterString = new String(startAfter);
+    final String startAfterString = new String(startAfter, Charsets.UTF_8);
     final String src = fsd.resolvePath(pc, srcArg, pathComponents);
     final INodesInPath iip = fsd.getINodesInPath(src, true);
 
@@ -195,8 +196,7 @@ class FSDirStatAndListingOp {
             cur.getLocalStoragePolicyID():
             BlockStoragePolicySuite.ID_UNSPECIFIED;
         listing[i] = createFileStatus(fsd, cur.getLocalNameBytes(), cur,
-            needLocation, fsd.getStoragePolicyID(curPolicy,
-                parentStoragePolicy), snapshot, isRawPath, inodesInPath);
+            needLocation, fsd.getStoragePolicyID(curPolicy, parentStoragePolicy), snapshot, isRawPath, inodesInPath);
         listingCnt++;
         if (needLocation) {
             // Once we  hit lsLimit locations, stop.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageUtil.java

@@ -23,6 +23,7 @@ import java.io.InputStream;
 import java.io.RandomAccessFile;
 import java.util.Arrays;
 
+import org.apache.commons.io.Charsets;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion.Feature;
@@ -32,7 +33,8 @@ import org.apache.hadoop.io.compress.CompressionCodec;
 
 @InterfaceAudience.Private
 public final class FSImageUtil {
-  public static final byte[] MAGIC_HEADER = "HDFSIMG1".getBytes();
+  public static final byte[] MAGIC_HEADER =
+      "HDFSIMG1".getBytes(Charsets.UTF_8);
   public static final int FILE_VERSION = 1;
 
   public static boolean checkFileFormat(RandomAccessFile file)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FileJournalManager.java

@@ -300,7 +300,7 @@ public class FileJournalManager implements JournalManager {
             .matcher(name);
         if (staleInprogressEditsMatch.matches()) {
           try {
-            long startTxId = Long.valueOf(staleInprogressEditsMatch.group(1));
+            long startTxId = Long.parseLong(staleInprogressEditsMatch.group(1));
             ret.add(new EditLogFile(f, startTxId, HdfsConstants.INVALID_TXID,
                 true));
             continue;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INode.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.hdfs.server.namenode;
 import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.nio.charset.Charset;
 import java.util.List;
 
 import org.apache.commons.logging.Log;
@@ -769,8 +770,7 @@ public abstract class INode implements INodeAttributes, Diff.Element<byte[]> {
 
   @VisibleForTesting
   public final void dumpTreeRecursively(PrintStream out) {
-    dumpTreeRecursively(new PrintWriter(out, true), new StringBuilder(),
-        Snapshot.CURRENT_STATE_ID);
+    out.println(dumpTreeRecursively().toString());
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java

@@ -974,10 +974,6 @@ class NameNodeRpcServer implements NamenodeProtocols {
   public DatanodeInfo[] getDatanodeReport(DatanodeReportType type)
   throws IOException {
     DatanodeInfo results[] = namesystem.datanodeReport(type);
-    if (results == null ) {
-      throw new IOException("Failed to get datanode report for " + type
-          + " datanodes.");
-    }
     return results;
   }
     
@@ -985,10 +981,6 @@ class NameNodeRpcServer implements NamenodeProtocols {
   public DatanodeStorageReport[] getDatanodeStorageReport(
       DatanodeReportType type) throws IOException {
     final DatanodeStorageReport[] reports = namesystem.getDatanodeStorageReport(type);
-    if (reports == null ) {
-      throw new IOException("Failed to get datanode storage report for " + type
-          + " datanodes.");
-    }
     return reports;
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NamenodeFsck.java

@@ -643,10 +643,6 @@ public class NamenodeFsck implements DataEncryptionKeyFactory {
         }
         if (fos == null) {
           fos = dfs.create(target + "/" + chain, true);
-          if (fos == null) {
-            throw new IOException("Failed to copy " + fullName +
-                " to /lost+found: could not store chain " + chain);
-          }
           chain++;
         }
         

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/XAttrPermissionFilter.java

@@ -100,7 +100,7 @@ public class XAttrPermissionFilter {
   static List<XAttr> filterXAttrsForApi(FSPermissionChecker pc,
       List<XAttr> xAttrs, boolean isRawPath) {
     assert xAttrs != null : "xAttrs can not be null";
-    if (xAttrs == null || xAttrs.isEmpty()) {
+    if (xAttrs.isEmpty()) {
       return xAttrs;
     }
     

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

@@ -1476,7 +1476,7 @@ public class DFSAdmin extends FsShell {
           } else {
             out.print("FAILED: ");
           }
-          out.printf("Change property %s\n\tFrom: \"%s\"\n\tTo: \"%s\"\n",
+          out.printf("Change property %s%n\tFrom: \"%s\"%n\tTo: \"%s\"%n",
               result.getKey().prop, result.getKey().oldVal,
               result.getKey().newVal);
           if (result.getValue().isPresent()) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/DelimitedImageVisitor.java

@@ -144,7 +144,7 @@ class DelimitedImageVisitor extends TextWriterImageVisitor {
     
     // Special case of file size, which is sum of the num bytes in each block
     if(element == ImageElement.NUM_BYTES)
-      fileSize += Long.valueOf(value);
+      fileSize += Long.parseLong(value);
     
     if(elements.containsKey(element) && element != ImageElement.NUM_BYTES)
       elements.put(element, value);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageHandler.java

@@ -17,11 +17,7 @@
  */
 package org.apache.hadoop.hdfs.tools.offlineImageViewer;
 
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
+import com.google.common.base.Charsets;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFutureListener;
@@ -30,19 +26,31 @@ import io.netty.channel.SimpleChannelInboundHandler;
 import io.netty.channel.group.ChannelGroup;
 import io.netty.handler.codec.http.DefaultFullHttpResponse;
 import io.netty.handler.codec.http.DefaultHttpResponse;
-import static io.netty.handler.codec.http.HttpResponseStatus.*;
-
 import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.HttpResponseStatus;
-import static io.netty.handler.codec.http.HttpVersion.*;
 import io.netty.handler.codec.http.QueryStringDecoder;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hdfs.web.JsonUtil;
-import org.apache.hadoop.hdfs.web.resources.ExceptionHandler;
 
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
 
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
+import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
+import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
+import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
+import static io.netty.handler.codec.http.HttpResponseStatus.METHOD_NOT_ALLOWED;
+import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.APPLICATION_JSON_UTF8;
+import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.WEBHDFS_PREFIX;
+import static org.apache.hadoop.hdfs.server.datanode.web.webhdfs.WebHdfsHandler.WEBHDFS_PREFIX_LENGTH;
 /**
  * Implement the read-only WebHDFS API for fsimage.
  */
@@ -67,7 +75,7 @@ class FSImageHandler extends SimpleChannelInboundHandler<HttpRequest> {
     if (request.getMethod() != HttpMethod.GET) {
       DefaultHttpResponse resp = new DefaultHttpResponse(HTTP_1_1,
         METHOD_NOT_ALLOWED);
-      resp.headers().set("Connection", "close");
+      resp.headers().set(CONNECTION, CLOSE);
       ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
       return;
     }
@@ -77,24 +85,29 @@ class FSImageHandler extends SimpleChannelInboundHandler<HttpRequest> {
 
     final String content;
     String path = getPath(decoder);
-    if ("GETFILESTATUS".equals(op)) {
-      content = image.getFileStatus(path);
-    } else if ("LISTSTATUS".equals(op)) {
-      content = image.listStatus(path);
-    } else if ("GETACLSTATUS".equals(op)) {
-      content = image.getAclStatus(path);
-    } else {
-      throw new IllegalArgumentException("Invalid value for webhdfs parameter" + " \"op\"");
+    switch (op) {
+      case "GETFILESTATUS":
+        content = image.getFileStatus(path);
+        break;
+      case "LISTSTATUS":
+        content = image.listStatus(path);
+        break;
+      case "GETACLSTATUS":
+        content = image.getAclStatus(path);
+        break;
+      default:
+        throw new IllegalArgumentException(
+            "Invalid value for webhdfs parameter" + " \"op\"");
     }
 
     LOG.info("op=" + op + " target=" + path);
 
     DefaultFullHttpResponse resp = new DefaultFullHttpResponse(
             HTTP_1_1, HttpResponseStatus.OK,
-            Unpooled.wrappedBuffer(content.getBytes()));
-    resp.headers().set("Content-Type", "application/json");
-    resp.headers().set("Content-Length", resp.content().readableBytes());
-    resp.headers().set("Connection", "close");
+            Unpooled.wrappedBuffer(content.getBytes(Charsets.UTF_8)));
+    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
+    resp.headers().set(CONTENT_LENGTH, resp.content().readableBytes());
+    resp.headers().set(CONNECTION, CLOSE);
     ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
   }
 
@@ -109,19 +122,19 @@ class FSImageHandler extends SimpleChannelInboundHandler<HttpRequest> {
     Exception e = cause instanceof Exception ? (Exception) cause : new
       Exception(cause);
     final String output = JsonUtil.toJsonString(e);
-    ByteBuf content = Unpooled.wrappedBuffer(output.getBytes());
+    ByteBuf content = Unpooled.wrappedBuffer(output.getBytes(Charsets.UTF_8));
     final DefaultFullHttpResponse resp = new DefaultFullHttpResponse(
             HTTP_1_1, INTERNAL_SERVER_ERROR, content);
 
-    resp.headers().set("Content-Type", "application/json");
+    resp.headers().set(CONTENT_TYPE, APPLICATION_JSON_UTF8);
     if (e instanceof IllegalArgumentException) {
       resp.setStatus(BAD_REQUEST);
     } else if (e instanceof FileNotFoundException) {
       resp.setStatus(NOT_FOUND);
     }
 
-    resp.headers().set("Content-Length", resp.content().readableBytes());
-    resp.headers().set("Connection", "close");
+    resp.headers().set(CONTENT_LENGTH, resp.content().readableBytes());
+    resp.headers().set(CONNECTION, CLOSE);
     ctx.write(resp).addListener(ChannelFutureListener.CLOSE);
   }
 
@@ -134,11 +147,11 @@ class FSImageHandler extends SimpleChannelInboundHandler<HttpRequest> {
   private static String getPath(QueryStringDecoder decoder)
           throws FileNotFoundException {
     String path = decoder.path();
-    if (path.startsWith("/webhdfs/v1/")) {
-      return path.substring(11);
+    if (path.startsWith(WEBHDFS_PREFIX)) {
+      return path.substring(WEBHDFS_PREFIX_LENGTH);
     } else {
       throw new FileNotFoundException("Path: " + path + " should " +
-              "start with \"/webhdfs/v1/\"");
+              "start with " + WEBHDFS_PREFIX);
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FSImageLoader.java

@@ -111,17 +111,15 @@ class FSImageLoader {
     }
 
     FsImageProto.FileSummary summary = FSImageUtil.loadSummary(file);
-    FileInputStream fin = null;
 
-    try {
+
+    try (FileInputStream fin = new FileInputStream(file.getFD())) {
       // Map to record INodeReference to the referred id
       ImmutableList<Long> refIdList = null;
       String[] stringTable = null;
       byte[][] inodes = null;
       Map<Long, long[]> dirmap = null;
 
-      fin = new FileInputStream(file.getFD());
-
       ArrayList<FsImageProto.FileSummary.Section> sections =
           Lists.newArrayList(summary.getSectionsList());
       Collections.sort(sections,
@@ -169,8 +167,6 @@ class FSImageLoader {
         }
       }
       return new FSImageLoader(stringTable, inodes, dirmap);
-    } finally {
-      IOUtils.cleanup(null, fin);
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FileDistributionCalculator.java

@@ -21,7 +21,7 @@ import java.io.BufferedInputStream;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.PrintWriter;
+import java.io.PrintStream;
 import java.io.RandomAccessFile;
 
 import org.apache.hadoop.conf.Configuration;
@@ -30,7 +30,6 @@ import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf.SectionName;
 import org.apache.hadoop.hdfs.server.namenode.FSImageUtil;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.FileSummary;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.util.LimitInputStream;
 
 import com.google.common.base.Preconditions;
@@ -67,7 +66,7 @@ final class FileDistributionCalculator {
   private final Configuration conf;
   private final long maxSize;
   private final int steps;
-  private final PrintWriter out;
+  private final PrintStream out;
 
   private final int[] distribution;
   private int totalFiles;
@@ -77,7 +76,7 @@ final class FileDistributionCalculator {
   private long maxFileSize;
 
   FileDistributionCalculator(Configuration conf, long maxSize, int steps,
-      PrintWriter out) {
+      PrintStream out) {
     this.conf = conf;
     this.maxSize = maxSize == 0 ? MAX_SIZE_DEFAULT : maxSize;
     this.steps = steps == 0 ? INTERVAL_DEFAULT : steps;
@@ -96,9 +95,7 @@ final class FileDistributionCalculator {
     }
 
     FileSummary summary = FSImageUtil.loadSummary(file);
-    FileInputStream in = null;
-    try {
-      in = new FileInputStream(file.getFD());
+    try (FileInputStream in = new FileInputStream(file.getFD())) {
       for (FileSummary.Section s : summary.getSectionsList()) {
         if (SectionName.fromString(s.getName()) != SectionName.INODE) {
           continue;
@@ -111,8 +108,6 @@ final class FileDistributionCalculator {
         run(is);
         output();
       }
-    } finally {
-      IOUtils.cleanup(null, in);
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/FileDistributionVisitor.java

@@ -159,10 +159,10 @@ class FileDistributionVisitor extends TextWriterImageVisitor {
         current.path = (value.equals("") ? "/" : value);
         break;
       case REPLICATION:
-        current.replication = Integer.valueOf(value);
+        current.replication = Integer.parseInt(value);
         break;
       case NUM_BYTES:
-        current.fileSize += Long.valueOf(value);
+        current.fileSize += Long.parseLong(value);
         break;
       default:
         break;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/LsImageVisitor.java

@@ -135,7 +135,7 @@ class LsImageVisitor extends TextWriterImageVisitor {
         perms = value;
         break;
       case REPLICATION:
-        replication = Integer.valueOf(value);
+        replication = Integer.parseInt(value);
         break;
       case USER_NAME:
         username = value;
@@ -144,7 +144,7 @@ class LsImageVisitor extends TextWriterImageVisitor {
         group = value;
         break;
       case NUM_BYTES:
-        filesize += Long.valueOf(value);
+        filesize += Long.parseLong(value);
         break;
       case MODIFICATION_TIME:
         modTime = value;
@@ -173,6 +173,6 @@ class LsImageVisitor extends TextWriterImageVisitor {
     if(element == ImageElement.INODE)
       newLine();
     else if (element == ImageElement.BLOCKS)
-      numBlocks = Integer.valueOf(value);
+      numBlocks = Integer.parseInt(value);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageViewerPB.java

@@ -18,9 +18,8 @@
 package org.apache.hadoop.hdfs.tools.offlineImageViewer;
 
 import java.io.EOFException;
-import java.io.File;
 import java.io.IOException;
-import java.io.PrintWriter;
+import java.io.PrintStream;
 import java.io.RandomAccessFile;
 
 import org.apache.commons.cli.CommandLine;
@@ -33,7 +32,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.net.NetUtils;
 
 /**
@@ -144,36 +142,33 @@ public class OfflineImageViewerPB {
     String processor = cmd.getOptionValue("p", "Web");
     String outputFile = cmd.getOptionValue("o", "-");
 
-    PrintWriter out = outputFile.equals("-") ?
-        new PrintWriter(System.out) : new PrintWriter(new File(outputFile));
-
     Configuration conf = new Configuration();
-    try {
-      if (processor.equals("FileDistribution")) {
-        long maxSize = Long.parseLong(cmd.getOptionValue("maxSize", "0"));
-        int step = Integer.parseInt(cmd.getOptionValue("step", "0"));
-        new FileDistributionCalculator(conf, maxSize, step, out)
-            .visit(new RandomAccessFile(inputFile, "r"));
-      } else if (processor.equals("XML")) {
-        new PBImageXmlWriter(conf, out).visit(new RandomAccessFile(inputFile,
-            "r"));
-      } else if (processor.equals("Web")) {
-        String addr = cmd.getOptionValue("addr", "localhost:5978");
-        WebImageViewer viewer = new WebImageViewer(NetUtils.createSocketAddr
-                (addr));
-        try {
-          viewer.start(inputFile);
-        } finally {
-          viewer.close();
-        }
+    try (PrintStream out = outputFile.equals("-") ?
+        System.out : new PrintStream(outputFile, "UTF-8")) {
+      switch (processor) {
+        case "FileDistribution":
+          long maxSize = Long.parseLong(cmd.getOptionValue("maxSize", "0"));
+          int step = Integer.parseInt(cmd.getOptionValue("step", "0"));
+          new FileDistributionCalculator(conf, maxSize, step, out).visit(
+              new RandomAccessFile(inputFile, "r"));
+          break;
+        case "XML":
+          new PBImageXmlWriter(conf, out).visit(
+              new RandomAccessFile(inputFile, "r"));
+          break;
+        case "Web":
+          String addr = cmd.getOptionValue("addr", "localhost:5978");
+          try (WebImageViewer viewer = new WebImageViewer(
+              NetUtils.createSocketAddr(addr))) {
+            viewer.start(inputFile);
+          }
+          break;
       }
       return 0;
     } catch (EOFException e) {
       System.err.println("Input file ended unexpectedly. Exiting");
     } catch (IOException e) {
       System.err.println("Encountered exception.  Exiting: " + e.getMessage());
-    } finally {
-      IOUtils.cleanup(null, out);
     }
     return -1;
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/PBImageXmlWriter.java

@@ -21,7 +21,7 @@ import java.io.BufferedInputStream;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.PrintWriter;
+import java.io.PrintStream;
 import java.io.RandomAccessFile;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -50,7 +50,6 @@ import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SnapshotDiffSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SnapshotSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.StringTableSection;
 import org.apache.hadoop.hdfs.util.XMLUtils;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.util.LimitInputStream;
 
 import com.google.common.collect.Lists;
@@ -62,10 +61,10 @@ import com.google.common.collect.Lists;
 @InterfaceAudience.Private
 public final class PBImageXmlWriter {
   private final Configuration conf;
-  private final PrintWriter out;
+  private final PrintStream out;
   private String[] stringTable;
 
-  public PBImageXmlWriter(Configuration conf, PrintWriter out) {
+  public PBImageXmlWriter(Configuration conf, PrintStream out) {
     this.conf = conf;
     this.out = out;
   }
@@ -76,9 +75,7 @@ public final class PBImageXmlWriter {
     }
 
     FileSummary summary = FSImageUtil.loadSummary(file);
-    FileInputStream fin = null;
-    try {
-      fin = new FileInputStream(file.getFD());
+    try (FileInputStream fin = new FileInputStream(file.getFD())) {
       out.print("<?xml version=\"1.0\"?>\n<fsimage>");
 
       ArrayList<FileSummary.Section> sections = Lists.newArrayList(summary
@@ -140,8 +137,6 @@ public final class PBImageXmlWriter {
         }
       }
       out.print("</fsimage>\n");
-    } finally {
-      IOUtils.cleanup(null, fin);
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZones.java

@@ -1265,11 +1265,11 @@ public class TestEncryptionZones {
     }
 
     // Run the XML OIV processor
-    StringWriter output = new StringWriter();
-    PrintWriter pw = new PrintWriter(output);
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    PrintStream pw = new PrintStream(output);
     PBImageXmlWriter v = new PBImageXmlWriter(new Configuration(), pw);
     v.visit(new RandomAccessFile(originalFsimage, "r"));
-    final String xml = output.getBuffer().toString();
+    final String xml = output.toString();
     SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
     parser.parse(new InputSource(new StringReader(xml)), new DefaultHandler());
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshot.java

@@ -25,15 +25,15 @@ import static org.junit.Assert.fail;
 
 import java.io.File;
 import java.io.IOException;
-import java.io.PrintWriter;
+import java.io.PrintStream;
 import java.io.RandomAccessFile;
-import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Random;
 
+import org.apache.commons.io.output.NullOutputStream;
 import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
@@ -57,6 +57,7 @@ import org.apache.hadoop.hdfs.server.namenode.INodeDirectory;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotTestHelper.TestDirectoryTree;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotTestHelper.TestDirectoryTree.Node;
 import org.apache.hadoop.hdfs.tools.offlineImageViewer.PBImageXmlWriter;
+import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.Time;
@@ -256,8 +257,7 @@ public class TestSnapshot {
         FSImageTestUtil.getFSImage(
         cluster.getNameNode()).getStorage().getStorageDir(0));
     assertNotNull("Didn't generate or can't find fsimage", originalFsimage);
-    StringWriter output = new StringWriter();
-    PrintWriter o = new PrintWriter(output);
+    PrintStream o = new PrintStream(NullOutputStream.NULL_OUTPUT_STREAM);
     PBImageXmlWriter v = new PBImageXmlWriter(new Configuration(), o);
     v.visit(new RandomAccessFile(originalFsimage, "r"));
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/TestOfflineImageViewer.java

@@ -20,18 +20,18 @@ package org.apache.hadoop.hdfs.tools.offlineImageViewer;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import java.io.FileWriter;
 import java.io.IOException;
+import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.RandomAccessFile;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.net.HttpURLConnection;
 import java.net.URI;
-import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.Collections;
 import java.util.Comparator;
@@ -43,6 +43,7 @@ import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 
+import org.apache.commons.io.output.NullOutputStream;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -186,10 +187,10 @@ public class TestOfflineImageViewer {
   @Test(expected = IOException.class)
   public void testTruncatedFSImage() throws IOException {
     File truncatedFile = folder.newFile();
-    StringWriter output = new StringWriter();
+    PrintStream output = new PrintStream(NullOutputStream.NULL_OUTPUT_STREAM);
     copyPartOfFile(originalFsimage, truncatedFile);
-    new FileDistributionCalculator(new Configuration(), 0, 0, new PrintWriter(
-        output)).visit(new RandomAccessFile(truncatedFile, "r"));
+    new FileDistributionCalculator(new Configuration(), 0, 0, output)
+        .visit(new RandomAccessFile(truncatedFile, "r"));
   }
 
   private void copyPartOfFile(File src, File dest) throws IOException {
@@ -208,20 +209,21 @@ public class TestOfflineImageViewer {
 
   @Test
   public void testFileDistributionCalculator() throws IOException {
-    StringWriter output = new StringWriter();
-    PrintWriter o = new PrintWriter(output);
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    PrintStream o = new PrintStream(output);
     new FileDistributionCalculator(new Configuration(), 0, 0, o)
         .visit(new RandomAccessFile(originalFsimage, "r"));
     o.close();
 
+    String outputString = output.toString();
     Pattern p = Pattern.compile("totalFiles = (\\d+)\n");
-    Matcher matcher = p.matcher(output.getBuffer());
+    Matcher matcher = p.matcher(outputString);
     assertTrue(matcher.find() && matcher.groupCount() == 1);
     int totalFiles = Integer.parseInt(matcher.group(1));
     assertEquals(NUM_DIRS * FILES_PER_DIR, totalFiles);
 
     p = Pattern.compile("totalDirectories = (\\d+)\n");
-    matcher = p.matcher(output.getBuffer());
+    matcher = p.matcher(outputString);
     assertTrue(matcher.find() && matcher.groupCount() == 1);
     int totalDirs = Integer.parseInt(matcher.group(1));
     // totalDirs includes root directory, empty directory, and xattr directory
@@ -236,7 +238,7 @@ public class TestOfflineImageViewer {
       }
     });
     p = Pattern.compile("maxFileSize = (\\d+)\n");
-    matcher = p.matcher(output.getBuffer());
+    matcher = p.matcher(output.toString("UTF-8"));
     assertTrue(matcher.find() && matcher.groupCount() == 1);
     assertEquals(maxFile.getLen(), Long.parseLong(matcher.group(1)));
   }
@@ -252,13 +254,13 @@ public class TestOfflineImageViewer {
   @Test
   public void testPBImageXmlWriter() throws IOException, SAXException,
       ParserConfigurationException {
-    StringWriter output = new StringWriter();
-    PrintWriter o = new PrintWriter(output);
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    PrintStream o = new PrintStream(output);
     PBImageXmlWriter v = new PBImageXmlWriter(new Configuration(), o);
     v.visit(new RandomAccessFile(originalFsimage, "r"));
     SAXParserFactory spf = SAXParserFactory.newInstance();
     SAXParser parser = spf.newSAXParser();
-    final String xml = output.getBuffer().toString();
+    final String xml = output.toString();
     parser.parse(new InputSource(new StringReader(xml)), new DefaultHandler());
   }
 
@@ -298,7 +300,7 @@ public class TestOfflineImageViewer {
       verifyHttpResponseCode(HttpURLConnection.HTTP_NOT_FOUND, url);
 
       // LISTSTATUS operation to a invalid prefix
-      url = new URL("http://localhost:" + port + "/webhdfs/v1?op=LISTSTATUS");
+      url = new URL("http://localhost:" + port + "/foo");
       verifyHttpResponseCode(HttpURLConnection.HTTP_NOT_FOUND, url);
 
       // GETFILESTATUS operation