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 org.jboss.netty.example.qotm;
17
18 import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
19 import org.jboss.netty.channel.ChannelPipeline;
20 import org.jboss.netty.channel.ChannelPipelineFactory;
21 import org.jboss.netty.channel.Channels;
22 import org.jboss.netty.channel.FixedReceiveBufferSizePredictorFactory;
23 import org.jboss.netty.channel.socket.DatagramChannel;
24 import org.jboss.netty.channel.socket.nio.NioDatagramChannelFactory;
25 import org.jboss.netty.handler.codec.string.StringDecoder;
26 import org.jboss.netty.handler.codec.string.StringEncoder;
27 import org.jboss.netty.util.CharsetUtil;
28
29 import java.net.InetSocketAddress;
30 import java.util.concurrent.Executors;
31
32 /**
33 * A UDP broadcast client that asks for a quote of the moment (QOTM) to {@link QuoteOfTheMomentServer}.
34 *
35 * Inspired by <a href="http://docs.oracle.com/javase/tutorial/networking/datagrams/clientServer.html">the official
36 * Java tutorial</a>.
37 */
38 public final class QuoteOfTheMomentClient {
39
40 static final int PORT = Integer.parseInt(System.getProperty("port", "7686"));
41
42 public static void main(String[] args) throws Exception {
43 ConnectionlessBootstrap b = new ConnectionlessBootstrap(
44 new NioDatagramChannelFactory(Executors.newCachedThreadPool()));
45
46 try {
47 // Configure the pipeline factory.
48 b.setPipelineFactory(new ChannelPipelineFactory() {
49 public ChannelPipeline getPipeline() {
50 return Channels.pipeline(
51 new StringEncoder(CharsetUtil.ISO_8859_1),
52 new StringDecoder(CharsetUtil.ISO_8859_1),
53 new QuoteOfTheMomentClientHandler());
54 }
55 });
56
57 // Enable broadcast
58 b.setOption("broadcast", "true");
59
60 // Allow packets as large as up to 1024 bytes (default is 768).
61 // You could increase or decrease this value to avoid truncated packets
62 // or to improve memory footprint respectively.
63 //
64 // Please also note that a large UDP packet might be truncated or
65 // dropped by your router no matter how you configured this option.
66 // In UDP, a packet is truncated or dropped if it is larger than a
67 // certain size, depending on router configuration. IPv4 routers
68 // truncate and IPv6 routers drop a large packet. That's why it is
69 // safe to send small packets in UDP.
70 b.setOption(
71 "receiveBufferSizePredictorFactory",
72 new FixedReceiveBufferSizePredictorFactory(1024));
73
74 DatagramChannel c = (DatagramChannel) b.bind(new InetSocketAddress(0));
75
76 // Broadcast the QOTM request to port 8080.
77 c.write("QOTM?", new InetSocketAddress("255.255.255.255", PORT));
78
79 // QuoteOfTheMomentClientHandler will close the DatagramChannel when a
80 // response is received. If the channel is not closed within 5 seconds,
81 // print an error message and quit.
82 if (!c.getCloseFuture().await(5000)) {
83 System.err.println("QOTM request timed out.");
84 c.close().sync();
85 }
86 } finally {
87 b.releaseExternalResources();
88 }
89 }
90 }