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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 <a href="http://mina.apache.org">Apache MINA Project</a>
    33   */
    34  public class ResultMessageDecoder extends AbstractMessageDecoder {
    35      private int code;
    36
    37      private boolean readCode;
    38
    39      public ResultMessageDecoder() {
    40          super(Constants.RESULT);
    41      }
    42
    43      @Override
    44      protected AbstractMessage decodeBody(IoSession session, IoBuffer 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  }