Unsigned.java

package whitebox.utilities;

import java.nio.ByteBuffer;

/**
 * Utility class to get and put unsigned values to a ByteBuffer object.
 * All methods here are static and take a ByteBuffer object argument.
 * Since java does not provide unsigned primitive types, each unsigned
 * value read from the buffer is promoted up to the next bigger primitive
 * data type.  getUnsignedByte() returns a short, getUnsignedShort() returns
 * an int and getUnsignedInt() returns a long.  There is no getUnsignedLong()
 * since there is no primitive type to hold the value returned.  If needed,
 * methods returning BigInteger could be implemented.
 * Likewise, the put methods take a value larger than the type they will
 * be assigning.  putUnsignedByte takes a short argument, etc.
 *
 * @author Ron Hitchens (ron@ronsoft.com)
 * @version $Id: Unsigned.java,v 1.1 2002/02/12 22:06:44 ron Exp $
 */
public class Unsigned {
    
    public static short getUnsignedByte(Byte b) {
        return ((short) (b & 0xff));
    }
    
    public static short getUnsignedByte(ByteBuffer bb) {
        return ((short) (bb.get() & 0xff));
    }

    public static void putUnsignedByte(ByteBuffer bb, int value) {
        bb.put((byte) (value & 0xff));
    }

    public static short getUnsignedByte(ByteBuffer bb, int position) {
        return ((short) (bb.get(position) & (short) 0xff));
    }

    public static void putUnsignedByte(ByteBuffer bb, int position,
            int value) {
        bb.put(position, (byte) (value & 0xff));
    }

    // ---------------------------------------------------------------
    public static int getUnsignedShort(ByteBuffer bb) {
        return (bb.getShort() & 0xffff);
    }

    public static void putUnsignedShort(ByteBuffer bb, int value) {
        bb.putShort((short) (value & 0xffff));
    }

    public static int getUnsignedShort(ByteBuffer bb, int position) {
        return (bb.getShort(position) & 0xffff);
    }

    public static void putUnsignedShort(ByteBuffer bb, int position,
            int value) {
        bb.putShort(position, (short) (value & 0xffff));
    }

    // ---------------------------------------------------------------
    public static long getUnsignedInt(ByteBuffer bb) {
        return ((long) bb.getInt() & 0xffffffffL);
    }

    public static void putUnsignedInt(ByteBuffer bb, long value) {
        bb.putInt((int) (value & 0xffffffffL));
    }

    public static long getUnsignedInt(ByteBuffer bb, int position) {
        return ((long) bb.getInt(position) & 0xffffffffL);
    }

    public static void putUnsignedInt(ByteBuffer bb, int position, long value) {
        bb.putInt(position, (int) (value & 0xffffffffL));
    }
}