1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the 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 io.netty.handler.timeout;
17
18 import io.netty.bootstrap.ServerBootstrap;
19 import io.netty.channel.Channel;
20 import io.netty.channel.ChannelDuplexHandler;
21 import io.netty.channel.ChannelHandlerContext;
22 import io.netty.channel.ChannelInitializer;
23
24 import java.util.concurrent.TimeUnit;
25
26 /**
27 * Raises a {@link ReadTimeoutException} when no data was read within a certain
28 * period of time.
29 *
30 * <pre>
31 * // The connection is closed when there is no inbound traffic
32 * // for 30 seconds.
33 *
34 * public class MyChannelInitializer extends {@link ChannelInitializer}<{@link Channel}> {
35 * public void initChannel({@link Channel} channel) {
36 * channel.pipeline().addLast("readTimeoutHandler", new {@link ReadTimeoutHandler}(30);
37 * channel.pipeline().addLast("myHandler", new MyHandler());
38 * }
39 * }
40 *
41 * // Handler should handle the {@link ReadTimeoutException}.
42 * public class MyHandler extends {@link ChannelDuplexHandler} {
43 * {@code @Override}
44 * public void exceptionCaught({@link ChannelHandlerContext} ctx, {@link Throwable} cause)
45 * throws {@link Exception} {
46 * if (cause instanceof {@link ReadTimeoutException}) {
47 * // do something
48 * } else {
49 * super.exceptionCaught(ctx, cause);
50 * }
51 * }
52 * }
53 *
54 * {@link ServerBootstrap} bootstrap = ...;
55 * ...
56 * bootstrap.childHandler(new MyChannelInitializer());
57 * ...
58 * </pre>
59 * @see WriteTimeoutHandler
60 * @see IdleStateHandler
61 */
62 public class ReadTimeoutHandler extends IdleStateHandler {
63 private boolean closed;
64
65 /**
66 * Creates a new instance.
67 *
68 * @param timeoutSeconds
69 * read timeout in seconds
70 */
71 public ReadTimeoutHandler(int timeoutSeconds) {
72 this(timeoutSeconds, TimeUnit.SECONDS);
73 }
74
75 /**
76 * Creates a new instance.
77 *
78 * @param timeout
79 * read timeout
80 * @param unit
81 * the {@link TimeUnit} of {@code timeout}
82 */
83 public ReadTimeoutHandler(long timeout, TimeUnit unit) {
84 super(timeout, 0, 0, unit);
85 }
86
87 @Override
88 protected final void channelIdle(ChannelHandlerContext ctx, IdleStateEvent evt) throws Exception {
89 assert evt.state() == IdleState.READER_IDLE;
90 readTimedOut(ctx);
91 }
92
93 /**
94 * Is called when a read timeout was detected.
95 */
96 protected void readTimedOut(ChannelHandlerContext ctx) throws Exception {
97 if (!closed) {
98 ctx.fireExceptionCaught(ReadTimeoutException.INSTANCE);
99 ctx.close();
100 closed = true;
101 }
102 }
103 }