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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  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,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.mina.example.sumup.codec;
21  
22  import org.apache.mina.common.ByteBuffer;
23  import org.apache.mina.common.IoSession;
24  import org.apache.mina.example.sumup.message.AbstractMessage;
25  import org.apache.mina.example.sumup.message.ResultMessage;
26  import org.apache.mina.filter.codec.ProtocolDecoderOutput;
27  import org.apache.mina.filter.codec.demux.MessageDecoder;
28  
29  /**
30   * A {@link MessageDecoder} that decodes {@link ResultMessage}.
31   *
32   * @author The Apache Directory Project (mina-dev@directory.apache.org)
33   * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (금, 13  7월 2007) $
34   */
35  public class ResultMessageDecoder extends AbstractMessageDecoder {
36      private int code;
37  
38      private boolean readCode;
39  
40      public ResultMessageDecoder() {
41          super(Constants.RESULT);
42      }
43  
44      protected AbstractMessage decodeBody(IoSession session, ByteBuffer in) {
45          if (!readCode) {
46              if (in.remaining() < Constants.RESULT_CODE_LEN) {
47                  return null; // Need more data.
48              }
49  
50              code = in.getShort();
51              readCode = true;
52          }
53  
54          if (code == Constants.RESULT_OK) {
55              if (in.remaining() < Constants.RESULT_VALUE_LEN) {
56                  return null;
57              }
58  
59              ResultMessage m = new ResultMessage();
60              m.setOk(true);
61              m.setValue(in.getInt());
62              readCode = false;
63              return m;
64          } else {
65              ResultMessage m = new ResultMessage();
66              m.setOk(false);
67              readCode = false;
68              return m;
69          }
70      }
71  
72      public void finishDecode(IoSession session, ProtocolDecoderOutput out)
73              throws Exception {
74      }
75  }