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20 package org.apache.mina.filter.codec;
21
22 import org.apache.mina.common.ByteBuffer;
23 import org.apache.mina.common.ByteBufferProxy;
24 import org.apache.mina.common.IoFilter;
25 import org.apache.mina.common.IoFilterAdapter;
26 import org.apache.mina.common.IoFilterChain;
27 import org.apache.mina.common.IoSession;
28 import org.apache.mina.common.WriteFuture;
29 import org.apache.mina.common.support.DefaultWriteFuture;
30 import org.apache.mina.filter.codec.support.SimpleProtocolDecoderOutput;
31 import org.apache.mina.filter.codec.support.SimpleProtocolEncoderOutput;
32 import org.apache.mina.util.SessionLog;
33
34
35
36
37
38
39
40
41
42 public class ProtocolCodecFilter extends IoFilterAdapter {
43 public static final String ENCODER = ProtocolCodecFilter.class.getName()
44 + ".encoder";
45
46 public static final String DECODER = ProtocolCodecFilter.class.getName()
47 + ".decoder";
48
49 private static final String DECODER_OUT = ProtocolCodecFilter.class.getName()
50 + ".decoderOut";
51
52 private static final Class[] EMPTY_PARAMS = new Class[0];
53
54 private static final ByteBuffer EMPTY_BUFFER = ByteBuffer.wrap(new byte[0]);
55
56 private final ProtocolCodecFactory factory;
57
58 public ProtocolCodecFilter(ProtocolCodecFactory factory) {
59 if (factory == null) {
60 throw new NullPointerException("factory");
61 }
62 this.factory = factory;
63 }
64
65 public ProtocolCodecFilter(final ProtocolEncoder encoder,
66 final ProtocolDecoder decoder) {
67 if (encoder == null) {
68 throw new NullPointerException("encoder");
69 }
70 if (decoder == null) {
71 throw new NullPointerException("decoder");
72 }
73
74 this.factory = new ProtocolCodecFactory() {
75 public ProtocolEncoder getEncoder() {
76 return encoder;
77 }
78
79 public ProtocolDecoder getDecoder() {
80 return decoder;
81 }
82 };
83 }
84
85 public ProtocolCodecFilter(final Class encoderClass,
86 final Class decoderClass) {
87 if (encoderClass == null) {
88 throw new NullPointerException("encoderClass");
89 }
90 if (decoderClass == null) {
91 throw new NullPointerException("decoderClass");
92 }
93 if (!ProtocolEncoder.class.isAssignableFrom(encoderClass)) {
94 throw new IllegalArgumentException("encoderClass: "
95 + encoderClass.getName());
96 }
97 if (!ProtocolDecoder.class.isAssignableFrom(decoderClass)) {
98 throw new IllegalArgumentException("decoderClass: "
99 + decoderClass.getName());
100 }
101 try {
102 encoderClass.getConstructor(EMPTY_PARAMS);
103 } catch (NoSuchMethodException e) {
104 throw new IllegalArgumentException(
105 "encoderClass doesn't have a public default constructor.");
106 }
107 try {
108 decoderClass.getConstructor(EMPTY_PARAMS);
109 } catch (NoSuchMethodException e) {
110 throw new IllegalArgumentException(
111 "decoderClass doesn't have a public default constructor.");
112 }
113
114 this.factory = new ProtocolCodecFactory() {
115 public ProtocolEncoder getEncoder() throws Exception {
116 return (ProtocolEncoder) encoderClass.newInstance();
117 }
118
119 public ProtocolDecoder getDecoder() throws Exception {
120 return (ProtocolDecoder) decoderClass.newInstance();
121 }
122 };
123 }
124
125 public void onPreAdd(IoFilterChain parent, String name,
126 NextFilter nextFilter) throws Exception {
127 if (parent.contains(ProtocolCodecFilter.class)) {
128 throw new IllegalStateException(
129 "A filter chain cannot contain more than one ProtocolCodecFilter.");
130 }
131 }
132
133 public void onPostRemove(IoFilterChain parent, String name,
134 NextFilter nextFilter) throws Exception {
135 disposeEncoder(parent.getSession());
136 disposeDecoder(parent.getSession());
137 disposeDecoderOut(parent.getSession());
138 }
139
140 public void messageReceived(NextFilter nextFilter, IoSession session,
141 Object message) throws Exception {
142 if (!(message instanceof ByteBuffer)) {
143 nextFilter.messageReceived(session, message);
144 return;
145 }
146
147 ByteBuffer in = (ByteBuffer) message;
148 ProtocolDecoder decoder = getDecoder(session);
149 ProtocolDecoderOutput decoderOut = getDecoderOut(session, nextFilter);
150
151 try {
152 while (in.hasRemaining()) {
153 int oldPos = in.position();
154 try {
155 synchronized (decoderOut) {
156 decoder.decode(session, in, decoderOut);
157 }
158
159 decoderOut.flush();
160 break;
161 } catch (Throwable t) {
162 ProtocolDecoderException pde;
163 if (t instanceof ProtocolDecoderException) {
164 pde = (ProtocolDecoderException) t;
165 } else {
166 pde = new ProtocolDecoderException(t);
167 }
168 pde.setHexdump(in.getHexDump());
169
170
171 decoderOut.flush();
172 nextFilter.exceptionCaught(session, pde);
173
174
175
176 if (in.position() == oldPos) {
177 break;
178 }
179 }
180 }
181 } finally {
182
183 in.release();
184 }
185 }
186
187 public void messageSent(NextFilter nextFilter, IoSession session,
188 Object message) throws Exception {
189 if (message instanceof HiddenByteBuffer) {
190 return;
191 }
192
193 if (!(message instanceof MessageByteBuffer)) {
194 nextFilter.messageSent(session, message);
195 return;
196 }
197
198 nextFilter.messageSent(session, ((MessageByteBuffer) message).message);
199 }
200
201 public void filterWrite(NextFilter nextFilter, IoSession session,
202 WriteRequest writeRequest) throws Exception {
203 Object message = writeRequest.getMessage();
204 if (message instanceof ByteBuffer) {
205 nextFilter.filterWrite(session, writeRequest);
206 return;
207 }
208
209 ProtocolEncoder encoder = getEncoder(session);
210 ProtocolEncoderOutputImpl encoderOut = getEncoderOut(session,
211 nextFilter, writeRequest);
212
213 try {
214 encoder.encode(session, message, encoderOut);
215 encoderOut.flush();
216 nextFilter.filterWrite(session, new WriteRequest(
217 new MessageByteBuffer(writeRequest.getMessage()),
218 writeRequest.getFuture(), writeRequest.getDestination()));
219 } catch (Throwable t) {
220 ProtocolEncoderException pee;
221 if (t instanceof ProtocolEncoderException) {
222 pee = (ProtocolEncoderException) t;
223 } else {
224 pee = new ProtocolEncoderException(t);
225 }
226 throw pee;
227 }
228 }
229
230 public void sessionClosed(NextFilter nextFilter, IoSession session)
231 throws Exception {
232
233 ProtocolDecoder decoder = getDecoder(session);
234 ProtocolDecoderOutput decoderOut = getDecoderOut(session, nextFilter);
235 try {
236 decoder.finishDecode(session, decoderOut);
237 } catch (Throwable t) {
238 ProtocolDecoderException pde;
239 if (t instanceof ProtocolDecoderException) {
240 pde = (ProtocolDecoderException) t;
241 } else {
242 pde = new ProtocolDecoderException(t);
243 }
244 throw pde;
245 } finally {
246
247 disposeEncoder(session);
248 disposeDecoder(session);
249 disposeDecoderOut(session);
250 decoderOut.flush();
251 }
252
253 nextFilter.sessionClosed(session);
254 }
255
256 private ProtocolEncoder getEncoder(IoSession session) throws Exception {
257 ProtocolEncoder encoder = (ProtocolEncoder) session
258 .getAttribute(ENCODER);
259 if (encoder == null) {
260 encoder = factory.getEncoder();
261 session.setAttribute(ENCODER, encoder);
262 }
263 return encoder;
264 }
265
266 private ProtocolEncoderOutputImpl getEncoderOut(IoSession session,
267 NextFilter nextFilter, WriteRequest writeRequest) {
268 return new ProtocolEncoderOutputImpl(session, nextFilter, writeRequest);
269 }
270
271 private ProtocolDecoder getDecoder(IoSession session) throws Exception {
272 ProtocolDecoder decoder = (ProtocolDecoder) session
273 .getAttribute(DECODER);
274 if (decoder == null) {
275 decoder = factory.getDecoder();
276 session.setAttribute(DECODER, decoder);
277 }
278 return decoder;
279 }
280
281 private ProtocolDecoderOutput getDecoderOut(IoSession session,
282 NextFilter nextFilter) {
283 ProtocolDecoderOutput out = (ProtocolDecoderOutput) session.getAttribute(DECODER_OUT);
284 if (out == null) {
285 out = new SimpleProtocolDecoderOutput(session, nextFilter);
286 session.setAttribute(DECODER_OUT, out);
287 }
288
289 return out;
290 }
291
292 private void disposeEncoder(IoSession session) {
293 ProtocolEncoder encoder = (ProtocolEncoder) session
294 .removeAttribute(ENCODER);
295 if (encoder == null) {
296 return;
297 }
298
299 try {
300 encoder.dispose(session);
301 } catch (Throwable t) {
302 SessionLog.warn(session, "Failed to dispose: "
303 + encoder.getClass().getName() + " (" + encoder + ')');
304 }
305 }
306
307 private void disposeDecoder(IoSession session) {
308 ProtocolDecoder decoder = (ProtocolDecoder) session
309 .removeAttribute(DECODER);
310 if (decoder == null) {
311 return;
312 }
313
314 try {
315 decoder.dispose(session);
316 } catch (Throwable t) {
317 SessionLog.warn(session, "Falied to dispose: "
318 + decoder.getClass().getName() + " (" + decoder + ')');
319 }
320 }
321
322 private void disposeDecoderOut(IoSession session) {
323 session.removeAttribute(DECODER_OUT);
324 }
325
326 private static class HiddenByteBuffer extends ByteBufferProxy {
327 private HiddenByteBuffer(ByteBuffer buf) {
328 super(buf);
329 }
330 }
331
332 private static class MessageByteBuffer extends ByteBufferProxy {
333 private final Object message;
334
335 private MessageByteBuffer(Object message) {
336 super(EMPTY_BUFFER);
337 this.message = message;
338 }
339
340 public void acquire() {
341
342 }
343
344 public void release() {
345
346 }
347 }
348
349 private static class ProtocolEncoderOutputImpl extends
350 SimpleProtocolEncoderOutput {
351 private final IoSession session;
352
353 private final NextFilter nextFilter;
354
355 private final WriteRequest writeRequest;
356
357 public ProtocolEncoderOutputImpl(IoSession session,
358 NextFilter nextFilter, WriteRequest writeRequest) {
359 this.session = session;
360 this.nextFilter = nextFilter;
361 this.writeRequest = writeRequest;
362 }
363
364 protected WriteFuture doFlush(ByteBuffer buf) {
365 WriteFuture future = new DefaultWriteFuture(session);
366 nextFilter.filterWrite(session, new WriteRequest(
367 new HiddenByteBuffer(buf), future, writeRequest
368 .getDestination()));
369 return future;
370 }
371 }
372 }