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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package examples.unix;
19  
20  import java.io.IOException;
21  import java.net.InetAddress;
22  
23  import org.apache.commons.net.time.TimeTCPClient;
24  import org.apache.commons.net.time.TimeUDPClient;
25  
26  /***
27   * This is an example program demonstrating how to use the TimeTCPClient
28   * and TimeUDPClient classes.  It's very similar to the simple Unix rdate
29   * command.  This program connects to the default time service port of a
30   * specified server, retrieves the time, and prints it to standard output.
31   * The default is to use the TCP port.  Use the -udp flag to use the UDP
32   * port.  You can test this program by using the NIST time server at
33   * 132.163.135.130 (warning: the IP address may change).
34   * <p>
35   * Usage: rdate [-udp] <hostname>
36   ***/
37  public final class rdate
38  {
39  
40      public static final void timeTCP(String host) throws IOException
41      {
42          TimeTCPClient client = new TimeTCPClient();
43  
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().toString());
48          client.disconnect();
49      }
50  
51      public static final void timeUDP(String host) throws IOException
52      {
53          TimeUDPClient client = new TimeUDPClient();
54  
55          // We want to timeout if a response takes longer than 60 seconds
56          client.setDefaultTimeout(60000);
57          client.open();
58          System.out.println(client.getDate(InetAddress.getByName(host)).toString());
59          client.close();
60      }
61  
62  
63      public static 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: rdate [-udp] <hostname>");
93              System.exit(1);
94          }
95  
96      }
97  
98  }
99