View Javadoc

1   package examples.ntp;
2   
3   /*
4    * Copyright 2001-2005 The Apache Software Foundation
5    *
6    * Licensed under the Apache License, Version 2.0 (the "License");
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18   
19  import java.io.IOException;
20  import java.net.InetAddress;
21  import org.apache.commons.net.TimeTCPClient;
22  import org.apache.commons.net.TimeUDPClient;
23  
24  /***
25   * This is an example program demonstrating how to use the TimeTCPClient
26   * and TimeUDPClient classes.
27   * This program connects to the default time service port of a
28   * specified server, retrieves the time, and prints it to standard output.
29   * See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A>
30   * for details.  The default is to use the TCP port.  Use the -udp flag to
31   * use the UDP port.
32   * <p>
33   * Usage: TimeClient [-udp] <hostname>
34   * <p>
35   ***/
36  public final class TimeClient
37  {
38  
39      public static final void timeTCP(String host) throws IOException
40      {
41          TimeTCPClient client = new TimeTCPClient();
42  	try {
43            // We want to timeout if a response takes longer than 60 seconds
44            client.setDefaultTimeout(60000);
45  	  client.connect(host);
46            System.out.println(client.getDate());
47  	} finally {
48            client.disconnect();
49  	}
50      }
51  
52      public static final void timeUDP(String host) throws IOException
53      {
54          TimeUDPClient client = new TimeUDPClient();
55  
56          // We want to timeout if a response takes longer than 60 seconds
57          client.setDefaultTimeout(60000);
58          client.open();
59          System.out.println(client.getDate(InetAddress.getByName(host)));
60          client.close();
61      }
62  
63      public static final void main(String[] args)
64      {
65  
66          if (args.length == 1)
67          {
68              try
69              {
70                  timeTCP(args[0]);
71              }
72              catch (IOException e)
73              {
74                  e.printStackTrace();
75                  System.exit(1);
76              }
77          }
78          else if (args.length == 2 && args[0].equals("-udp"))
79          {
80              try
81              {
82                  timeUDP(args[1]);
83              }
84              catch (IOException e)
85              {
86                  e.printStackTrace();
87                  System.exit(1);
88              }
89          }
90          else
91          {
92              System.err.println("Usage: TimeClient [-udp] <hostname>");
93              System.exit(1);
94          }
95  
96      }
97  
98  }
99