View Javadoc

    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  }