This commit includes the following changes:

* Add VisibleForTesting, Nullable annotations
* Add Preconditions class ported from Google Guava
* Add license notes for Guava and sbt-extras
* Add checkNotNull preconditions
* Fix typos

Author: xerial

LICENCE.sbt-extras.txt

@@ -0,0 +1,27 @@
+// Generated from http://www.opensource.org/licenses/bsd-license.php
+Copyright (c) 2011, Paul Phillips. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its contributors
+may be used to endorse or promote products derived from this software
+without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

NOTICE

@@ -0,0 +1,5 @@
+This product includes the software developed by third-party:
+
+ * Google Guava https://code.google.com/p/guava-libraries/  (APL2)
+ * sbt-extras: https://github.com/paulp/sbt-extras  (BSD)  (LICENSE.sbt-extras.txt)
+

msgpack-core/src/main/java/org/msgpack/core/MessageBuffer.java

@@ -8,6 +8,7 @@
 import java.nio.BufferOverflowException;
 import java.nio.ByteBuffer;
 import java.util.concurrent.atomic.AtomicInteger;
+import static org.msgpack.core.Preconditions.*;
 
 import static sun.misc.Unsafe.ARRAY_BYTE_BASE_OFFSET;
 import static sun.misc.Unsafe.ARRAY_BYTE_INDEX_SCALE;
@@ -137,11 +138,12 @@ public static MessageBuffer wrap(ByteBuffer bb) {
     }
 
     /**
-     * Creates a new MessageBuffer instance bakeed by ByteBuffer
+     * Creates a new MessageBuffer instance backed by ByteBuffer
      * @param bb
      * @return
      */
     private static MessageBuffer newMessageBuffer(ByteBuffer bb) {
+       checkNotNull(bb);
        try {
            // We need to use reflection to create MessageBuffer instances in order to prevent TypeProfile generation for getInt method. TypeProfile will be
            // generated to resolve one of the method references when two or more classes overrides the method.
@@ -162,6 +164,7 @@ private static MessageBuffer newMessageBuffer(ByteBuffer bb) {
      * @return
      */
     private static MessageBuffer newMessageBuffer(byte[] arr) {
+        checkNotNull(arr);
         try {
             Constructor<?> constructor = msgBufferClass.getDeclaredConstructor(byte[].class);
             return (MessageBuffer) constructor.newInstance(arr);

msgpack-core/src/main/java/org/msgpack/core/MessageBufferInput.java

@@ -4,6 +4,8 @@
 import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
+import static org.msgpack.core.Preconditions.*;
+
 
 /**
  * Provides a sequence of MessageBuffers that contains message packed data.
@@ -31,7 +33,7 @@ class ArrayMessageBufferInput implements MessageBufferInput {
     private boolean isRead = false;
 
     ArrayMessageBufferInput(byte[] arr) {
-        this.buffer = MessageBuffer.wrap(arr);
+        this.buffer = MessageBuffer.wrap(checkNotNull(arr, "input array is null"));
     }
 
     @Override
@@ -56,9 +58,7 @@ class MessageBufferInputStream implements MessageBufferInput {
     private byte[] buffer = new byte[8192];
 
     MessageBufferInputStream(InputStream in) {
-        if(in == null)
-            throw new NullPointerException("MessageBufferInputStream: input is null");
-        this.in = in;
+        this.in = checkNotNull(in, "input is null");
     }
 
     @Override
@@ -81,8 +81,12 @@ public MessageBuffer next() throws IOException {
 
     @Override
     public void close() throws IOException {
-        in.close();
-        buffer = null;
+        try {
+            in.close();
+        }
+        finally {
+            buffer = null;
+        }
     }
 }
 
@@ -91,8 +95,7 @@ class MessageBufferInputChannel implements MessageBufferInput {
     private final ReadableByteChannel channel;
 
     MessageBufferInputChannel(ReadableByteChannel channel) {
-        assert(channel != null);
-        this.channel = channel;
+        this.channel = checkNotNull(channel, "input channel is null");
     }
 
     @Override

msgpack-core/src/main/java/org/msgpack/core/MessageBufferOutput.java

@@ -1,12 +1,10 @@
 package org.msgpack.core;
 
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
-import java.nio.channels.FileChannel;
 import java.nio.channels.WritableByteChannel;
+import static org.msgpack.core.Preconditions.*;
 
 /**
  * Provides a sequence of MessageBuffers for packing the input data
@@ -38,7 +36,7 @@ class MessageBufferOutputStream implements MessageBufferOutput {
     private final OutputStream out;
 
     MessageBufferOutputStream(OutputStream out) {
-        this.out = out;
+        this.out = checkNotNull(out, "output is null");
     }
 
     @Override
@@ -68,7 +66,7 @@ class MessageBufferOutputChannel implements MessageBufferOutput {
     private final WritableByteChannel channel;
 
     MessageBufferOutputChannel(WritableByteChannel channel) {
-        this.channel = channel;
+        this.channel = checkNotNull(channel, "output channel is null");
     }
 
     @Override

msgpack-core/src/main/java/org/msgpack/core/MessageFormat.java

@@ -1,6 +1,7 @@
 package org.msgpack.core;
 
 import org.msgpack.core.MessagePack.Code;
+import org.msgpack.core.annotations.VisibleForTesting;
 
 import java.io.IOException;
 
@@ -322,7 +323,7 @@ public static MessageFormat valueOf(final byte b) {
         return formatTable[table[b & 0xFF]];
     }
 
-
+    @VisibleForTesting
     static MessageFormat toMessageFormat(final byte b) {
         if (Code.isPosFixInt(b)) {
             return POSFIXINT;

msgpack-core/src/main/java/org/msgpack/core/MessagePacker.java

@@ -19,6 +19,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import static org.msgpack.core.MessagePack.Code.*;
+import static org.msgpack.core.Preconditions.*;
 
 /**
  * Writer of message packed data.
@@ -49,7 +50,7 @@ public MessagePacker(MessageBufferOutput out) {
     }
 
     public MessagePacker(MessageBufferOutput out, int bufferSize) {
-        assert(out != null);
+        checkNotNull(out, "MessageBufferOutput is null");
         this.out = out;
         this.buffer = MessageBuffer.newDirectBuffer(bufferSize);
         this.position = 0;

msgpack-core/src/main/java/org/msgpack/core/MessageUnpacker.java

@@ -24,6 +24,8 @@
 import java.util.ArrayList;
 
 import org.msgpack.core.MessagePack.Code;
+import static org.msgpack.core.Preconditions.*;
+
 
 /**
  * Reader of message-packed values.
@@ -70,7 +72,7 @@ public static class Options {
     private boolean reachedEOF = false;
 
     public MessageUnpacker(MessageBufferInput in) {
-        this.in = in;
+        this.in = checkNotNull(in, "MessageBufferInput");
     }