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1   package examples.ntp;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one or more
5    * contributor license agreements.  See the NOTICE file distributed with
6    * this work for additional information regarding copyright ownership.
7    * The ASF licenses this file to You under the Apache License, Version 2.0
8    * (the "License"); you may not use this file except in compliance with
9    * the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19   
20  import java.io.IOException;
21  import java.net.InetAddress;
22  import org.apache.commons.net.TimeTCPClient;
23  import org.apache.commons.net.TimeUDPClient;
24  
25  /***
26   * This is an example program demonstrating how to use the TimeTCPClient
27   * and TimeUDPClient classes.
28   * This program connects to the default time service port of a
29   * specified server, retrieves the time, and prints it to standard output.
30   * See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A>
31   * for details.  The default is to use the TCP port.  Use the -udp flag to
32   * use the UDP port.
33   * <p>
34   * Usage: TimeClient [-udp] <hostname>
35   * <p>
36   ***/
37  public final class TimeClient
38  {
39  
40      public static final void timeTCP(String host) throws IOException
41      {
42          TimeTCPClient client = new TimeTCPClient();
43  	try {
44            // We want to timeout if a response takes longer than 60 seconds
45            client.setDefaultTimeout(60000);
46  	  client.connect(host);
47            System.out.println(client.getDate());
48  	} finally {
49            client.disconnect();
50  	}
51      }
52  
53      public static final void timeUDP(String host) throws IOException
54      {
55          TimeUDPClient client = new TimeUDPClient();
56  
57          // We want to timeout if a response takes longer than 60 seconds
58          client.setDefaultTimeout(60000);
59          client.open();
60          System.out.println(client.getDate(InetAddress.getByName(host)));
61          client.close();
62      }
63  
64      public static final void main(String[] args)
65      {
66  
67          if (args.length == 1)
68          {
69              try
70              {
71                  timeTCP(args[0]);
72              }
73              catch (IOException e)
74              {
75                  e.printStackTrace();
76                  System.exit(1);
77              }
78          }
79          else if (args.length == 2 && args[0].equals("-udp"))
80          {
81              try
82              {
83                  timeUDP(args[1]);
84              }
85              catch (IOException e)
86              {
87                  e.printStackTrace();
88                  System.exit(1);
89              }
90          }
91          else
92          {
93              System.err.println("Usage: TimeClient [-udp] <hostname>");
94              System.exit(1);
95          }
96  
97      }
98  
99  }
100