Java Convert via ByteBuffer toByteArray(ReadableByteChannel channel)

Description

to Byte Array

License

Apache License

Declaration

public static byte[] toByteArray(ReadableByteChannel channel) throws IOException 

Method Source Code

//package com.java2s;
/*/*from   w  ww  .  j  ava  2s .  co  m*/
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;

public class Main {
    public static byte[] toByteArray(ReadableByteChannel channel) throws IOException {
        final ByteArrayOutputStream out = new ByteArrayOutputStream();
        copy(channel, Channels.newChannel(out));
        return out.toByteArray();
    }

    public static void copy(ReadableByteChannel in, WritableByteChannel out) throws IOException {
        // First, we need a buffer to hold blocks of copied bytes.
        ByteBuffer buffer = ByteBuffer.allocateDirect(32 * 1024);

        // Now loop until no more bytes to read and the buffer is empty
        while (in.read(buffer) != -1 || buffer.position() > 0) {
            // The read() call leaves the buffer in "fill mode". To prepare
            // to write bytes from the bufferwe have to put it in "drain mode"
            // by flipping it: setting limit to position and position to zero
            buffer.flip();

            // Now write some or all of the bytes out to the output channel
            out.write(buffer);

            // Compact the buffer by discarding bytes that were written,
            // and shifting any remaining bytes. This method also
            // prepares the buffer for the next call to read() by setting the
            // position to the limit and the limit to the buffer capacity.
            buffer.compact();
        }
    }
}

Related

1. toByteArray(int value)
2. toByteArray(int[] data, boolean bigEndian)
3. toByteArray(int[] intArray)
4. toByteArray(long[] data)
5. ToByteArray(long[] data)
6. toByteArray(String bits)
7. ToByteArray(String hexString)
8. toByteArray(String value)
9. toByteArray(UUID uniqueId)