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   /*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project licenses this file to you under the Apache License,
    * version 2.0 (the "License"); you may not use this file except in compliance
    * with the License. You may obtain a copy of the License at:
    *
    *   http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
   * License for the specific language governing permissions and limitations
   * under the License.
   */
  package org.jboss.netty.example.qotm;
  
  import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
  import org.jboss.netty.channel.ChannelPipeline;
  import org.jboss.netty.channel.ChannelPipelineFactory;
  import org.jboss.netty.channel.Channels;
  import org.jboss.netty.channel.FixedReceiveBufferSizePredictorFactory;
  import org.jboss.netty.channel.socket.DatagramChannel;
  import org.jboss.netty.channel.socket.nio.NioDatagramChannelFactory;
  import org.jboss.netty.handler.codec.string.StringDecoder;
  import org.jboss.netty.handler.codec.string.StringEncoder;
  import org.jboss.netty.util.CharsetUtil;
  
  import java.net.InetSocketAddress;
  import java.util.concurrent.Executors;
  
  /**
   * A UDP broadcast client that asks for a quote of the moment (QOTM) to {@link QuoteOfTheMomentServer}.
   *
   * Inspired by <a href="http://docs.oracle.com/javase/tutorial/networking/datagrams/clientServer.html">the official
   * Java tutorial</a>.
   */
  public final class QuoteOfTheMomentClient {
  
      static final int PORT = Integer.parseInt(System.getProperty("port", "7686"));
  
      public static void main(String[] args) throws Exception {
          ConnectionlessBootstrap b = new ConnectionlessBootstrap(
                  new NioDatagramChannelFactory(Executors.newCachedThreadPool()));
  
          try {
              // Configure the pipeline factory.
              b.setPipelineFactory(new ChannelPipelineFactory() {
                  public ChannelPipeline getPipeline() {
                      return Channels.pipeline(
                              new StringEncoder(CharsetUtil.ISO_8859_1),
                              new StringDecoder(CharsetUtil.ISO_8859_1),
                              new QuoteOfTheMomentClientHandler());
                  }
              });
  
              // Enable broadcast
              b.setOption("broadcast", "true");
  
              // Allow packets as large as up to 1024 bytes (default is 768).
              // You could increase or decrease this value to avoid truncated packets
              // or to improve memory footprint respectively.
              //
              // Please also note that a large UDP packet might be truncated or
              // dropped by your router no matter how you configured this option.
              // In UDP, a packet is truncated or dropped if it is larger than a
              // certain size, depending on router configuration.  IPv4 routers
              // truncate and IPv6 routers drop a large packet.  That's why it is
              // safe to send small packets in UDP.
              b.setOption(
                      "receiveBufferSizePredictorFactory",
                      new FixedReceiveBufferSizePredictorFactory(1024));
  
              DatagramChannel c = (DatagramChannel) b.bind(new InetSocketAddress(0));
  
              // Broadcast the QOTM request to port 8080.
              c.write("QOTM?", new InetSocketAddress("255.255.255.255", PORT));
  
              // QuoteOfTheMomentClientHandler will close the DatagramChannel when a
              // response is received.  If the channel is not closed within 5 seconds,
              // print an error message and quit.
              if (!c.getCloseFuture().await(5000)) {
                  System.err.println("QOTM request timed out.");
                  c.close().sync();
              }
          } finally {
              b.releaseExternalResources();
          }
      }
  }