1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package org.jboss.netty.channel;
17
18 /**
19 * A {@link ChannelHandler} that is notified when it is added to or removed
20 * from a {@link ChannelPipeline}.
21 *
22 * <h3>Invalid access to the {@link ChannelHandlerContext}</h3>
23 *
24 * Calling {@link ChannelHandlerContext#sendUpstream(ChannelEvent)} or
25 * {@link ChannelHandlerContext#sendDownstream(ChannelEvent)} in
26 * {@link #beforeAdd(ChannelHandlerContext)} or {@link #afterRemove(ChannelHandlerContext)}
27 * might lead to an unexpected behavior. It is because the context object
28 * might not have been fully added to the pipeline or the context object is not
29 * a part of the pipeline anymore respectively.
30 *
31 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
32 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
33 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
34 */
35 public interface LifeCycleAwareChannelHandler extends ChannelHandler {
36 void beforeAdd(ChannelHandlerContext ctx) throws Exception;
37 void afterAdd(ChannelHandlerContext ctx) throws Exception;
38 void beforeRemove(ChannelHandlerContext ctx) throws Exception;
39 void afterRemove(ChannelHandlerContext ctx) throws Exception;
40 }