01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one
03: * or more contributor license agreements. See the NOTICE file
04: * distributed with this work for additional information
05: * regarding copyright ownership. The ASF licenses this file
06: * to you under the Apache License, Version 2.0 (the
07: * "License"); you may not use this file except in compliance
08: * with the License. You may obtain a copy of the License at
09: *
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.handler.chain;
21:
22: import org.apache.mina.common.IoHandler;
23: import org.apache.mina.common.IoHandlerAdapter;
24: import org.apache.mina.common.IoSession;
25:
26: /**
27: * An {@link IoHandler} which executes an {@link IoHandlerChain}
28: * on a <tt>messageReceived</tt> event.
29: *
30: * @author The Apache MINA Project (dev@mina.apache.org)
31: * @version $Rev: 576217 $, $Date: 2007-09-16 17:55:27 -0600 (Sun, 16 Sep 2007) $
32: */
33: public class ChainedIoHandler extends IoHandlerAdapter {
34: private final IoHandlerChain chain;
35:
36: /**
37: * Creates a new instance which contains an empty {@link IoHandlerChain}.
38: */
39: public ChainedIoHandler() {
40: chain = new IoHandlerChain();
41: }
42:
43: /**
44: * Creates a new instance which executes the specified
45: * {@link IoHandlerChain} on a <tt>messageReceived</tt> event.
46: *
47: * @param chain an {@link IoHandlerChain} to execute
48: */
49: public ChainedIoHandler(IoHandlerChain chain) {
50: if (chain == null) {
51: throw new NullPointerException("chain");
52: }
53: this .chain = chain;
54: }
55:
56: /**
57: * Returns the {@link IoHandlerCommand} this handler will use to
58: * handle <tt>messageReceived</tt> events.
59: */
60: public IoHandlerChain getChain() {
61: return chain;
62: }
63:
64: /**
65: * Handles the specified <tt>messageReceived</tt> event with the
66: * {@link IoHandlerCommand} or {@link IoHandlerChain} you specified
67: * in the constructor.
68: */
69: @Override
70: public void messageReceived(IoSession session, Object message)
71: throws Exception {
72: chain.execute(null, session, message);
73: }
74: }
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