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.handler.chain;
21
22 import org.apache.mina.core.service.IoHandler;
23 import org.apache.mina.core.service.IoHandlerAdapter;
24 import org.apache.mina.core.session.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: 671827 $, $Date: 2008-06-26 10:49:48 +0200 (jeu, 26 jun 2008) $
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 }