unsignedutils.java

FMJ（freedom media for java)是java视频开发的新选择

package net.sf.fmj.utility;

/**
* Because java does not support unsigned types, a collection of useful functions for 
* treating types as unsigned.
* 
* @author Ken Larson
*/ 
public final class UnsignedUtils
{
	private UnsignedUtils()
	{	super();
	}
	
	public static final int MAX_UBYTE = ((int) Byte.MAX_VALUE) * 2 + 1;		// 255
	public static final int MAX_USHORT = ((int) Short.MAX_VALUE) * 2 + 1;	// 65535
	public static final long MAX_UINT = ((long) Integer.MAX_VALUE) * 2 + 1;	

	public static int uByteToInt(byte value)
	{	if (value >= 0)
			return value;
		else
			return MAX_UBYTE + 1 + value;
	}
	
	public static int uShortToInt(short value)
	{	if (value >= 0)
			return value;
		else
			return MAX_USHORT + 1 + value;
	}

	public static long uIntToLong(int value)
	{	if (value >= 0)
			return value;
		else
			return MAX_UINT + 1L + value;
	}	
}