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Unsigned.javaAPI DocExample3124Tue Feb 12 13:06:44 GMT 2002com.ronsoft.books.nio.buffers

Unsigned

public class Unsigned extends Object
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 $

Fields Summary
Constructors Summary
Methods Summary
public static shortgetUnsignedByte(java.nio.ByteBuffer bb)

		return ((short)(bb.get() & 0xff));
public static shortgetUnsignedByte(java.nio.ByteBuffer bb, int position)

		return ((short)(bb.get (position) & (short)0xff));
public static longgetUnsignedInt(java.nio.ByteBuffer bb, int position)

		return ((long)bb.getInt (position) & 0xffffffffL);
public static longgetUnsignedInt(java.nio.ByteBuffer bb)

		return ((long)bb.getInt() & 0xffffffffL);
public static intgetUnsignedShort(java.nio.ByteBuffer bb)

		return (bb.getShort() & 0xffff);
public static intgetUnsignedShort(java.nio.ByteBuffer bb, int position)

		return (bb.getShort (position) & 0xffff);
public static voidmain(java.lang.String[] argv)

		ByteBuffer buffer = ByteBuffer.allocate (20);

		buffer.clear();
		Unsigned.putUnsignedByte (buffer, 255);
		Unsigned.putUnsignedByte (buffer, 128);
		Unsigned.putUnsignedShort (buffer, 0xcafe);
		Unsigned.putUnsignedInt (buffer, 0xcafebabe);

		for (int i = 0; i < 8; i++) {
			System.out.println ("" + i + ": "
				+ Integer.toHexString ((int)getUnsignedByte (buffer, i)));
		}

		System.out.println ("2: " + Integer.toHexString (getUnsignedShort (buffer, 2)));
		System.out.println ("4: " + Long.toHexString (getUnsignedInt (buffer, 4)));
public static voidputUnsignedByte(java.nio.ByteBuffer bb, int value)

		bb.put ((byte)(value & 0xff));
public static voidputUnsignedByte(java.nio.ByteBuffer bb, int position, int value)

		bb.put (position, (byte)(value & 0xff));
public static voidputUnsignedInt(java.nio.ByteBuffer bb, long value)

		bb.putInt ((int)(value & 0xffffffffL));
public static voidputUnsignedInt(java.nio.ByteBuffer bb, int position, long value)

		bb.putInt (position, (int)(value & 0xffffffffL));
public static voidputUnsignedShort(java.nio.ByteBuffer bb, int value)

		bb.putShort ((short)(value & 0xffff));
public static voidputUnsignedShort(java.nio.ByteBuffer bb, int position, int value)

		bb.putShort (position, (short)(value & 0xffff));