/** This class provides methods for converting between byte values
 *  and int's in the range 0..255.  In Java, the universe of values
 *  associated with the type byte is -128..127.  This class makes it
 *  convenient to use values of type byte to represent values in the
 *  range 0..255.  The mapping is simply that byte values normally
 *  interpreted as having the values -128..-1 are instead interpreted
 *  to have values 128..255, respectively.  This corresponds to
 *  interpreting the leading bit to be in the "128 column" rather
 *  than, as in 2's complement notation, the "-128 column".
 *
*/

public class BytePositiveIntConverter{

   /** Returns an int value corresponding to the given byte, which is
   *   assumed to encode an integer in the range 0..255 using a straight
   *   binary encoding.
   *
   *   @return (int)k if k >= 0; (int)(k+256) otherwise
   */
   public int byteToPosInt(byte k) { 
      return (int)(k >= 0  ?  k : k + 256);
   }

   /** Returns a byte value that encodes a non-negative int in the
   *   range 0..255 using a straight binary encoding.
   *
   *   pre: 0 <= m < 256
   *   @return m if m < 128 and m - 256 otherwise
   */
   public byte posIntToByte(int m) { 
      return (byte)(m < 128  ?  m : m - 256);
   }

}