https://issues.apache.org/jira/browse/AMQ-5578

Remove unnecessary zero init block as the java spec requires the
allocations to do this already.  Fix some warnings.

activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/journal/Journal.java

@@ -16,28 +16,45 @@
  */
 package org.apache.activemq.store.kahadb.disk.journal;
 
-import java.io.*;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.zip.Adler32;
 import java.util.zip.Checksum;
+
 import org.apache.activemq.store.kahadb.disk.util.LinkedNode;
-import org.apache.activemq.store.kahadb.disk.util.SequenceSet;
-import org.apache.activemq.util.*;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.apache.activemq.store.kahadb.disk.util.LinkedNodeList;
 import org.apache.activemq.store.kahadb.disk.util.SchedulerTimerTask;
 import org.apache.activemq.store.kahadb.disk.util.Sequence;
+import org.apache.activemq.util.ByteSequence;
+import org.apache.activemq.util.DataByteArrayInputStream;
+import org.apache.activemq.util.DataByteArrayOutputStream;
+import org.apache.activemq.util.IOHelper;
+import org.apache.activemq.util.RecoverableRandomAccessFile;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Manages DataFiles
- *
- *
  */
 public class Journal {
     public static final String CALLER_BUFFER_APPENDER = "org.apache.kahadb.journal.CALLER_BUFFER_APPENDER";
@@ -88,8 +105,7 @@ public class Journal {
     }
 
     private static byte[] createBatchControlRecordHeader() {
-        try {
+        try (DataByteArrayOutputStream os = new DataByteArrayOutputStream();) {
-            DataByteArrayOutputStream os = new DataByteArrayOutputStream();
             os.writeInt(BATCH_CONTROL_RECORD_SIZE);
             os.writeByte(BATCH_CONTROL_RECORD_TYPE);
             os.write(BATCH_CONTROL_RECORD_MAGIC);
@@ -163,6 +179,7 @@ public class Journal {
         appender = callerBufferAppender ? new CallerBufferingDataFileAppender(this) : new DataFileAppender(this);
 
         File[] files = directory.listFiles(new FilenameFilter() {
+            @Override
             public boolean accept(File dir, String n) {
                 return dir.equals(directory) && n.startsWith(filePrefix) && n.endsWith(fileSuffix);
             }
@@ -217,12 +234,13 @@ public class Journal {
             totalLength.addAndGet(lastAppendLocation.get().getOffset() - maxFileLength);
         }
 
-
         cleanupTask = new Runnable() {
+            @Override
             public void run() {
                 cleanup();
             }
         };
+
         this.timer = new Timer("KahaDB Scheduler", true);
         TimerTask task = new SchedulerTimerTask(cleanupTask);
         this.timer.scheduleAtFixedRate(task, DEFAULT_CLEANUP_INTERVAL,DEFAULT_CLEANUP_INTERVAL);
@@ -230,21 +248,18 @@ public class Journal {
         LOG.trace("Startup took: "+(end-start)+" ms");
     }
 
-
     public void preallocateEntireJournalDataFile(RecoverableRandomAccessFile file) {
 
         if (PreallocationScope.ENTIRE_JOURNAL == preallocationScope) {
 
             if (PreallocationStrategy.OS_KERNEL_COPY == preallocationStrategy) {
                 doPreallocationKernelCopy(file);
-
+            } else if (PreallocationStrategy.ZEROS == preallocationStrategy) {
-            }else if (PreallocationStrategy.ZEROS == preallocationStrategy) {
                 doPreallocationZeros(file);
-            }
+            } else {
-            else {
                 doPreallocationSparseFile(file);
             }
-        }else {
+        } else {
             LOG.info("Using journal preallocation scope of batch allocation");
         }
     }
@@ -260,10 +275,7 @@ public class Journal {
 
     private void doPreallocationZeros(RecoverableRandomAccessFile file) {
         ByteBuffer buffer = ByteBuffer.allocate(maxFileLength);
-        for (int i = 0; i < maxFileLength; i++) {
+        buffer.limit(maxFileLength);
-            buffer.put((byte) 0x00);
-        }
-        buffer.flip();
 
         try {
             FileChannel channel = file.getChannel();
@@ -385,10 +397,10 @@ public class Journal {
         }
     }
 
-
     public int checkBatchRecord(DataFileAccessor reader, int offset) throws IOException {
         byte controlRecord[] = new byte[BATCH_CONTROL_RECORD_SIZE];
-        DataByteArrayInputStream controlIs = new DataByteArrayInputStream(controlRecord);
+
+        try (DataByteArrayInputStream controlIs = new DataByteArrayInputStream(controlRecord);) {
 
             reader.readFully(offset, controlRecord);
 
@@ -422,11 +434,10 @@ public class Journal {
                 if( expectedChecksum!=checksum.getValue() ) {
                     return -1;
                 }
-
             }
             return size;
         }
-
+    }
 
     void addToTotalLength(int size) {
         totalLength.addAndGet(size);
@@ -784,6 +795,7 @@ public class Journal {
     public void setReplicationTarget(ReplicationTarget replicationTarget) {
         this.replicationTarget = replicationTarget;
     }
+
     public ReplicationTarget getReplicationTarget() {
         return replicationTarget;
     }
@@ -869,10 +881,12 @@ public class Journal {
             hash = (int)(file ^ offset);
         }
 
+        @Override
         public int hashCode() {
             return hash;
         }
 
+        @Override
         public boolean equals(Object obj) {
             if (obj instanceof WriteKey) {
                 WriteKey di = (WriteKey)obj;