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    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.localtime;
    17
    18  import java.net.InetSocketAddress;
    19  import java.util.ArrayList;
    20  import java.util.Collection;
    21  import java.util.Iterator;
    22  import java.util.List;
    23  import java.util.concurrent.Executors;
    24
    25  import org.jboss.netty.bootstrap.ClientBootstrap;
    26  import org.jboss.netty.channel.Channel;
    27  import org.jboss.netty.channel.ChannelFuture;
    28  import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
    29
    30  /**
    31   * Sends a list of continent/city pairs to a {@link LocalTimeServer} to
    32   * get the local times of the specified cities.
    33   */
    34  public class LocalTimeClient {
    35
    36      private final String host;
    37      private final int port;
    38      private final Collection<String> cities;
    39
    40      public LocalTimeClient(String host, int port, Collection<String> cities) {
    41          this.host = host;
    42          this.port = port;
    43          this.cities = new ArrayList<String>();
    44          this.cities.addAll(cities);
    45      }
    46
    47      public void run() {
    48          // Set up.
    49          ClientBootstrap bootstrap = new ClientBootstrap(
    50                  new NioClientSocketChannelFactory(
    51                          Executors.newCachedThreadPool(),
    52                          Executors.newCachedThreadPool()));
    53
    54          // Configure the event pipeline factory.
    55          bootstrap.setPipelineFactory(new LocalTimeClientPipelineFactory());
    56
    57          // Make a new connection.
    58          ChannelFuture connectFuture =
    59              bootstrap.connect(new InetSocketAddress(host, port));
    60
    61          // Wait until the connection is made successfully.
    62          Channel channel = connectFuture.awaitUninterruptibly().getChannel();
    63
    64          // Get the handler instance to initiate the request.
    65          LocalTimeClientHandler handler =
    66              channel.getPipeline().get(LocalTimeClientHandler.class);
    67
    68          // Request and get the response.
    69          List<String> response = handler.getLocalTimes(cities);
    70          // Close the connection.
    71          channel.close().awaitUninterruptibly();
    72
    73          // Shut down all thread pools to exit.
    74          bootstrap.releaseExternalResources();
    75
    76          // Print the response at last but not least.
    77          Iterator<String> i1 = cities.iterator();
    78          Iterator<String> i2 = response.iterator();
    79          while (i1.hasNext()) {
    80              System.out.format("%28s: %s%n", i1.next(), i2.next());
    81          }
    82      }
    83
    84      public static void main(String[] args) throws Exception {
    85          // Print usage if necessary.
    86          if (args.length < 3) {
    87              printUsage();
    88              return;
    89          }
    90
    91          // Parse options.
    92          String host = args[0];
    93          int port = Integer.parseInt(args[1]);
    94          Collection<String> cities = parseCities(args, 2);
    95          if (cities == null) {
    96              return;
    97          }
    98
    99          new LocalTimeClient(host, port, cities).run();
    100     }
    101
    102     private static void printUsage() {
    103         System.err.println(
    104                 "Usage: " + LocalTimeClient.class.getSimpleName() +
    105                 " <host> <port> <continent/city_name> ...");
    106         System.err.println(
    107                 "Example: " + LocalTimeClient.class.getSimpleName() +
    108                 " localhost 8080 America/New_York Asia/Seoul");
    109     }
    110
    111     private static List<String> parseCities(String[] args, int offset) {
    112         List<String> cities = new ArrayList<String>();
    113         for (int i = offset; i < args.length; i ++) {
    114             if (!args[i].matches("^[_A-Za-z]+/[_A-Za-z]+$")) {
    115                 System.err.println("Syntax error: '" + args[i] + "'");
    116                 printUsage();
    117                 return null;
    118             }
    119             cities.add(args[i].trim());
    120         }
    121         return cities;
    122     }
    123 }