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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.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   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
35   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
36   *
37   * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
38   */
39  public class LocalTimeClient {
40  
41      public static void main(String[] args) throws Exception {
42          // Print usage if necessary.
43          if (args.length < 3) {
44              printUsage();
45              return;
46          }
47  
48          // Parse options.
49          String host = args[0];
50          int port = Integer.parseInt(args[1]);
51          Collection<String> cities = parseCities(args, 2);
52          if (cities == null) {
53              return;
54          }
55  
56          // Set up.
57          ClientBootstrap bootstrap = new ClientBootstrap(
58                  new NioClientSocketChannelFactory(
59                          Executors.newCachedThreadPool(),
60                          Executors.newCachedThreadPool()));
61  
62          // Configure the event pipeline factory.
63          bootstrap.setPipelineFactory(new LocalTimeClientPipelineFactory());
64  
65          // Make a new connection.
66          ChannelFuture connectFuture =
67              bootstrap.connect(new InetSocketAddress(host, port));
68  
69          // Wait until the connection is made successfully.
70          Channel channel = connectFuture.awaitUninterruptibly().getChannel();
71  
72          // Get the handler instance to initiate the request.
73          LocalTimeClientHandler handler =
74              channel.getPipeline().get(LocalTimeClientHandler.class);
75  
76          // Request and get the response.
77          List<String> response = handler.getLocalTimes(cities);
78          // Close the connection.
79          channel.close().awaitUninterruptibly();
80  
81          // Shut down all thread pools to exit.
82          bootstrap.releaseExternalResources();
83  
84          // Print the response at last but not least.
85          Iterator<String> i1 = cities.iterator();
86          Iterator<String> i2 = response.iterator();
87          while (i1.hasNext()) {
88              System.out.format("%28s: %s%n", i1.next(), i2.next());
89          }
90      }
91  
92      private static void printUsage() {
93          System.err.println(
94                  "Usage: " + LocalTimeClient.class.getSimpleName() +
95                  " <host> <port> <continent/city_name> ...");
96          System.err.println(
97                  "Example: " + LocalTimeClient.class.getSimpleName() +
98                  " localhost 8080 America/New_York Asia/Seoul");
99      }
100 
101     private static List<String> parseCities(String[] args, int offset) {
102         List<String> cities = new ArrayList<String>();
103         for (int i = offset; i < args.length; i ++) {
104             if (!args[i].matches("^[_A-Za-z]+/[_A-Za-z]+$")) {
105                 System.err.println("Syntax error: '" + args[i] + "'");
106                 printUsage();
107                 return null;
108             }
109             cities.add(args[i].trim());
110         }
111         return cities;
112     }
113 }