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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.example.qotm;
17  
18  import java.net.InetSocketAddress;
19  import java.util.concurrent.Executors;
20  
21  import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
22  import org.jboss.netty.channel.ChannelPipeline;
23  import org.jboss.netty.channel.ChannelPipelineFactory;
24  import org.jboss.netty.channel.Channels;
25  import org.jboss.netty.channel.FixedReceiveBufferSizePredictorFactory;
26  import org.jboss.netty.channel.socket.DatagramChannel;
27  import org.jboss.netty.channel.socket.DatagramChannelFactory;
28  import org.jboss.netty.channel.socket.nio.NioDatagramChannelFactory;
29  import org.jboss.netty.handler.codec.string.StringDecoder;
30  import org.jboss.netty.handler.codec.string.StringEncoder;
31  import org.jboss.netty.util.CharsetUtil;
32  
33  /**
34   * A UDP broadcast client that asks for a quote of the moment (QOTM) to
35   * {@link QuoteOfTheMomentServer}.
36   *
37   * Inspired by <a href="http://java.sun.com/docs/books/tutorial/networking/datagrams/clientServer.html">the official Java tutorial</a>.
38   *
39   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
40   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
41   * @version $Rev: 2104 $, $Date: 2010-01-28 16:50:28 +0900 (Thu, 28 Jan 2010) $
42   */
43  public class QuoteOfTheMomentClient {
44  
45      public static void main(String[] args) throws Exception {
46          DatagramChannelFactory f =
47              new NioDatagramChannelFactory(Executors.newCachedThreadPool());
48  
49          ConnectionlessBootstrap b = new ConnectionlessBootstrap(f);
50  
51          // Configure the pipeline factory.
52          b.setPipelineFactory(new ChannelPipelineFactory() {
53              public ChannelPipeline getPipeline() throws Exception {
54                  return Channels.pipeline(
55                          new StringEncoder(CharsetUtil.ISO_8859_1),
56                          new StringDecoder(CharsetUtil.ISO_8859_1),
57                          new QuoteOfTheMomentClientHandler());
58              }
59          });
60  
61          // Enable broadcast
62          b.setOption("broadcast", "true");
63  
64          // Allow packets as large as up to 1024 bytes (default is 768).
65          // You could increase or decrease this value to avoid truncated packets
66          // or to improve memory footprint respectively.
67          //
68          // Please also note that a large UDP packet might be truncated or
69          // dropped by your router no matter how you configured this option.
70          // In UDP, a packet is truncated or dropped if it is larger than a
71          // certain size, depending on router configuration.  IPv4 routers
72          // truncate and IPv6 routers drop a large packet.  That's why it is
73          // safe to send small packets in UDP.
74          b.setOption(
75                  "receiveBufferSizePredictorFactory",
76                  new FixedReceiveBufferSizePredictorFactory(1024));
77  
78          DatagramChannel c = (DatagramChannel) b.bind(new InetSocketAddress(0));
79  
80          // Broadcast the QOTM request to port 8080.
81          c.write("QOTM?", new InetSocketAddress("255.255.255.255", 8080));
82  
83          // QuoteOfTheMomentClientHandler will close the DatagramChannel when a
84          // response is received.  If the channel is not closed within 5 seconds,
85          // print an error message and quit.
86          if (!c.getCloseFuture().awaitUninterruptibly(5000)) {
87              System.err.println("QOTM request timed out.");
88              c.close().awaitUninterruptibly();
89          }
90  
91          f.releaseExternalResources();
92      }
93  }