Source for gnu.CORBA.ByteArrayComparator

   1: /* ByteArrayComparator.java --
   2:    Copyright (C) 2005 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.CORBA;
  40: 
  41: import java.util.Comparator;
  42: 
  43: /**
  44:  * A byte array comparator for mapping with CORBA object keys.
  45:  *
  46:  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
  47:  */
  48: public class ByteArrayComparator
  49:   implements Comparator
  50: {
  51:   /**
  52:    * Compare arrays first by absolute equality, then by length
  53:    * and then (byte to byte) by content.
  54:    *
  55:    * @return 0 if arrays are equal, some comparison value otherwise.
  56:    */
  57:   public int compare(Object an_a, Object a_b)
  58:   {
  59:     if (an_a == a_b)
  60:       return 0;
  61: 
  62:     byte[] a = null;
  63:     byte[] b = null;
  64:     try
  65:       {
  66:         a = (byte[]) an_a;
  67:         b = (byte[]) a_b;
  68:       }
  69:     catch (Exception ex)
  70:       {
  71:         throw new InternalError(an_a.getClass().getName() + "," +
  72:                                 a_b.getClass().getName()
  73:                                );
  74:       }
  75: 
  76:     if (a.length != b.length)
  77:       return a.length - b.length;
  78:     else
  79:       {
  80:         // The array sizes must be equal.
  81:         for (int i = 0; i < b.length; i++)
  82:           {
  83:             if (a [ i ] != b [ i ])
  84:               return a [ i ] - b [ i ];
  85:           }
  86:       }
  87: 
  88:     return 0;
  89:   }
  90: }