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1   /*
2    *   @(#) $Id: ResultMessageDecoder.java 332218 2005-11-10 03:52:42Z trustin $
3    *
4    *   Copyright 2004 The Apache Software Foundation
5    *
6    *   Licensed under the Apache License, Version 2.0 (the "License");
7    *   you may not use this file except in compliance with the License.
8    *   You may obtain a copy of the License at
9    *
10   *       http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *   Unless required by applicable law or agreed to in writing, software
13   *   distributed under the License is distributed on an "AS IS" BASIS,
14   *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   *   See the License for the specific language governing permissions and
16   *   limitations under the License.
17   *
18   */
19  package org.apache.mina.examples.sumup.codec;
20  
21  import org.apache.mina.common.ByteBuffer;
22  import org.apache.mina.examples.sumup.message.AbstractMessage;
23  import org.apache.mina.examples.sumup.message.ResultMessage;
24  import org.apache.mina.protocol.ProtocolSession;
25  import org.apache.mina.protocol.codec.MessageDecoder;
26  
27  /***
28   * A {@link MessageDecoder} that decodes {@link ResultMessage}.
29   *
30   * @author The Apache Directory Project
31   * @version $Rev: 332218 $, $Date: 2005-11-10 12:52:42 +0900 $
32   */
33  public class ResultMessageDecoder extends AbstractMessageDecoder
34  {
35      private int code;
36      private boolean readCode;
37      
38      public ResultMessageDecoder()
39      {
40          super( Constants.RESULT );
41      }
42  
43      protected AbstractMessage decodeBody( ProtocolSession session, ByteBuffer in )
44      {
45          if( !readCode )
46          {
47              if( in.remaining() < Constants.RESULT_CODE_LEN )
48              {
49                  return null; // Need more data.
50              }
51              
52              code = in.getShort();
53              readCode = true;
54          }
55          
56          if( code == Constants.RESULT_OK )
57          {
58              if( in.remaining() < Constants.RESULT_VALUE_LEN )
59              {
60                  return null;
61              }
62              
63              ResultMessage m = new ResultMessage();
64              m.setOk( true );
65              m.setValue( in.getInt() );
66              readCode = false;
67              return m;
68          }
69          else
70          {
71              ResultMessage m = new ResultMessage();
72              m.setOk( false );
73              readCode = false;
74              return m;
75          }
76      }
77  }