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 */
32 public class ChainedIoHandler extends IoHandlerAdapter {
33 private final IoHandlerChain chain;
34
35 /**
36 * Creates a new instance which contains an empty {@link IoHandlerChain}.
37 */
38 public ChainedIoHandler() {
39 chain = new IoHandlerChain();
40 }
41
42 /**
43 * Creates a new instance which executes the specified
44 * {@link IoHandlerChain} on a <tt>messageReceived</tt> event.
45 *
46 * @param chain an {@link IoHandlerChain} to execute
47 */
48 public ChainedIoHandler(IoHandlerChain chain) {
49 if (chain == null) {
50 throw new NullPointerException("chain");
51 }
52 this.chain = chain;
53 }
54
55 /**
56 * Returns the {@link IoHandlerCommand} this handler will use to
57 * handle <tt>messageReceived</tt> events.
58 */
59 public IoHandlerChain getChain() {
60 return chain;
61 }
62
63 /**
64 * Handles the specified <tt>messageReceived</tt> event with the
65 * {@link IoHandlerCommand} or {@link IoHandlerChain} you specified
66 * in the constructor.
67 */
68 @Override
69 public void messageReceived(IoSession session, Object message)
70 throws Exception {
71 chain.execute(null, session, message);
72 }
73 }