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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.core.buffer.IoBuffer;
23  import org.apache.mina.core.session.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 MINA Project (dev@mina.apache.org)
33   * @version $Rev: 671827 $, $Date: 2008-06-26 10:49:48 +0200 (jeu, 26 jun 2008) $
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      @Override
45      protected AbstractMessage decodeBody(IoSession session, IoBuffer in) {
46          if (!readCode) {
47              if (in.remaining() < Constants.RESULT_CODE_LEN) {
48                  return null; // Need more data.
49              }
50  
51              code = in.getShort();
52              readCode = true;
53          }
54  
55          if (code == Constants.RESULT_OK) {
56              if (in.remaining() < Constants.RESULT_VALUE_LEN) {
57                  return null;
58              }
59  
60              ResultMessage m = new ResultMessage();
61              m.setOk(true);
62              m.setValue(in.getInt());
63              readCode = false;
64              return m;
65          } else {
66              ResultMessage m = new ResultMessage();
67              m.setOk(false);
68              readCode = false;
69              return m;
70          }
71      }
72  
73      public void finishDecode(IoSession session, ProtocolDecoderOutput out)
74              throws Exception {
75      }
76  }