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1   // 
2   //Copyright (c) 2003, Caltha - Gajda, Krzewski, Mach, Potempski Sp.J. 
3   //All rights reserved. 
4   //   
5   //Redistribution and use in source and binary forms, with or without modification,  
6   //are permitted provided that the following conditions are met: 
7   //   
8   //* Redistributions of source code must retain the above copyright notice,  
9   //this list of conditions and the following disclaimer. 
10  //* Redistributions in binary form must reproduce the above copyright notice,  
11  //this list of conditions and the following disclaimer in the documentation  
12  //and/or other materials provided with the distribution. 
13  //* Neither the name of the Caltha - Gajda, Krzewski, Mach, Potempski Sp.J.  
14  //nor the names of its contributors may be used to endorse or promote products  
15  //derived from this software without specific prior written permission. 
16  // 
17  //THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"  
18  //AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED  
19  //WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
20  //IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,  
21  //INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,  
22  //BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
23  //OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,  
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27  //
28  
29  package org.objectledge.encodings.encoders;
30  
31  /**
32   * Base class for Encoder classes. Defines masks and encoding method.
33   *
34   * @author <a href="mailto:dgajda@caltha.pl">Damian Gajda</a>
35   * @version $Id: CharEncoder.java,v 1.1 2004/02/02 18:59:00 zwierzem Exp $
36   */
37  public abstract class CharEncoder
38  {
39      private final int prefixMask = 0xff00;
40      private final int suffixMask = 0x00ff;
41      private final int prefixShift = 8;
42  
43      /*** This encoding's name. */
44      protected String encodingName = null;
45  
46      /*** Returns this encoding name.
47       * @return name of the encoding.
48       */
49      public String getEncoding()
50      {
51          return encodingName;
52      }
53  
54      /***
55       * Encodes a char in a given encoding.
56       * @param c character to be encoded
57       * @return array of characters representing encoded character -
58       * 		<code>null</code> if character cannot be represented in this encoding.
59       */
60      public char[] encode(char c)
61      {
62          return suffixIndex[ prefixIndex[(c & prefixMask) >> prefixShift] + (c & suffixMask) ];
63      }
64  
65      /*** Index of mappings - prefix part */
66      protected int[] prefixIndex = null;
67  
68      /*** Index of mappings - suffix part */
69      protected char[][] suffixIndex = null;
70  }
71