Java ByteBuffer to Int readUnsignedShort(ByteBuffer buffer)

Description

read Unsigned Short

License

Open Source License

Declaration

public static int readUnsignedShort(ByteBuffer buffer) 

Method Source Code

//package com.java2s;
/*//  ww  w . j a va2s .com
 * OpenFire - a Java API to access the XFire instant messaging network.
 * Copyright (C) 2007 Iain McGinniss
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
    
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
    
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

import java.io.IOException;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.ReadableByteChannel;

public class Main {
    public static int readUnsignedShort(ReadableByteChannel channel) throws IOException {
        ByteBuffer readBuffer = createBuffer(2);
        readAllBytesOrFail(channel, readBuffer, 2);
        return readUnsignedShort(readBuffer);
    }

    public static int readUnsignedShort(ByteBuffer buffer) {
        return buffer.getShort() & 0xFFFF;
    }

    public static ByteBuffer createBuffer(int size) {
        ByteBuffer buffer = ByteBuffer.allocate(size);
        buffer.order(ByteOrder.LITTLE_ENDIAN);

        return buffer;
    }

    public static void readAllBytesOrFail(ReadableByteChannel channel, ByteBuffer buffer, int numBytes)
            throws IOException {
        if (!readAllBytesOrNone(channel, buffer, numBytes)) {
            throw new IOException("no more bytes left in channel to read");
        }
    }

    public static boolean readAllBytesOrNone(ReadableByteChannel channel, ByteBuffer buffer, int numBytes)
            throws IOException {
        buffer.rewind();
        buffer.limit(numBytes);

        int totalBytesRead = 0;
        int bytesRead = channel.read(buffer);
        if (bytesRead <= 0) {
            // no bytes available at all
            return false;
        }
        totalBytesRead += bytesRead;
        while (totalBytesRead < numBytes) {
            bytesRead = channel.read(buffer);
            if (bytesRead == -1) {
                throw new IOException("insufficient but non-zero amount of bytes left in channel");
            }

            totalBytesRead += bytesRead;
        }

        buffer.flip();

        return true;
    }
}

Related

1. readUnsignedInt(ByteBuffer buffer)
2. readUnsignedInt(ByteBuffer buffer, int index)
3. readUnsignedInt(ByteBuffer byteBuf)
4. readUnsignedMedium(ByteBuffer buf)
5. readUnsignedShort(ByteBuffer bb)
6. readUnsignedTriByte(ByteBuffer buffer)
7. readUnsignedVarint(ByteBuffer buffer)
8. readVarInt(ByteBuffer buff)
9. readVarInt(ByteBuffer buff)