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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.filter.codec;
21  
22  import org.apache.mina.core.buffer.IoBuffer;
23  import org.apache.mina.core.session.IoSession;
24  
25  /**
26   * Encodes higher-level message objects into binary or protocol-specific data.
27   * MINA invokes {@link #encode(IoSession, Object, ProtocolEncoderOutput)}
28   * method with message which is popped from the session write queue, and then
29   * the encoder implementation puts encoded messages (typically {@link IoBuffer}s)
30   * into {@link ProtocolEncoderOutput} by calling {@link ProtocolEncoderOutput#write(Object)}.
31   * <p>
32   * Please refer to
33   * <a href="../../../../../xref-examples/org/apache/mina/examples/reverser/TextLineEncoder.html"><code>TextLineEncoder</code></a>
34   * example.
35   *
36   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
37   * 
38   * @see ProtocolEncoderException
39   */
40  public interface ProtocolEncoder {
41  
42      /**
43       * Encodes higher-level message objects into binary or protocol-specific data.
44       * MINA invokes {@link #encode(IoSession, Object, ProtocolEncoderOutput)}
45       * method with message which is popped from the session write queue, and then
46       * the encoder implementation puts encoded messages (typically {@link IoBuffer}s)
47       * into {@link ProtocolEncoderOutput}.
48       *
49       * @throws Exception if the message violated protocol specification
50       */
51      void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception;
52  
53      /**
54       * Releases all resources related with this encoder.
55       *
56       * @throws Exception if failed to dispose all resources
57       */
58      void dispose(IoSession session) throws Exception;
59  }