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20 package org.apache.mina.filter.codec;
21
22 import java.nio.ByteBuffer;
23
24 import org.apache.mina.api.AbstractIoFilter;
25 import org.apache.mina.api.IoFilter;
26 import org.apache.mina.api.IoSession;
27 import org.apache.mina.codec.ProtocolDecoder;
28 import org.apache.mina.codec.ProtocolDecoderException;
29 import org.apache.mina.codec.ProtocolEncoder;
30 import org.apache.mina.filterchain.ReadFilterChainController;
31 import org.apache.mina.filterchain.WriteFilterChainController;
32 import org.apache.mina.session.AttributeKey;
33 import org.apache.mina.session.WriteRequest;
34 import org.apache.mina.util.Assert;
35 import org.slf4j.Logger;
36 import org.slf4j.LoggerFactory;
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45
46 public class ProtocolCodecFilter<MESSAGE, ENCODED, ENCODING_STATE, DECODING_STATE> extends AbstractIoFilter {
47
48 private static final Logger LOGGER = LoggerFactory.getLogger(ProtocolCodecFilter.class);
49
50
51 private final ProtocolEncoder<MESSAGE, ENCODED, ENCODING_STATE> encoder;
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54 private final ProtocolDecoder<ENCODED, MESSAGE, DECODING_STATE> decoder;
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57 private static final AttributeKey<Object> ENCODER = new AttributeKey<Object>(Object.class, "internal_encoder");
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60 private static final AttributeKey<Object> DECODER = new AttributeKey<Object>(Object.class, "internal_decoder");
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65
66 public ProtocolCodecFilter(ProtocolEncoder<MESSAGE, ENCODED, ENCODING_STATE> encoder,
67 ProtocolDecoder<ENCODED, MESSAGE, DECODING_STATE> decoder) {
68 Assert.assertNotNull(encoder, "encoder");
69 Assert.assertNotNull(decoder, "decoder");
70 this.encoder = encoder;
71 this.decoder = decoder;
72 }
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84 @SuppressWarnings("unchecked")
85 @Override
86 public void messageReceived(IoSession session, Object in, ReadFilterChainController controller) {
87 LOGGER.debug("Processing a MESSAGE_RECEIVED for session {}", session);
88
89 DECODING_STATE state = getDecodingState(session);
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91
92 MESSAGE msg;
93 try {
94 while (((msg = decoder.decode((ENCODED) in, state)) != null)) {
95 controller.callReadNextFilter(msg);
96 }
97 } catch (ProtocolDecoderException e) {
98 LOGGER.debug("decoding exception : ", e);
99 throw e;
100 }
101 }
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105
106 @SuppressWarnings("unchecked")
107 @Override
108 public void messageWriting(IoSession session, WriteRequest message, WriteFilterChainController controller) {
109 LOGGER.debug("Processing a MESSAGE_WRITTING for session {}", session);
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111 ENCODED encoded = encoder.encode((MESSAGE) message.getMessage(), getEncodingState(session));
112 message.setMessage(encoded);
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114 controller.callWriteNextFilter(message);
115 }
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120 @Override
121 public void sessionOpened(IoSession session) {
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124 ENCODING_STATE encodingState = encoder.createEncoderState();
125 session.setAttribute(ENCODER, encodingState);
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127 DECODING_STATE decodingState = decoder.createDecoderState();
128 session.setAttribute(DECODER, decodingState);
129 }
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134 @Override
135 public void sessionClosed(IoSession session) {
136 decoder.finishDecode(getDecodingState(session));
137
138 }
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142 @SuppressWarnings("unchecked")
143 private DECODING_STATE getDecodingState(IoSession session) {
144 return (DECODING_STATE) session.getAttribute(DECODER);
145 }
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147 @SuppressWarnings("unchecked")
148 private ENCODING_STATE getEncodingState(IoSession session) {
149 return (ENCODING_STATE) session.getAttribute(ENCODER);
150 }
151
152 }