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 org.apache.commons.net.examples.unix;
19
20 import java.io.IOException;
21 import java.net.InetAddress;
22 import java.time.Duration;
23
24 import org.apache.commons.net.time.TimeTCPClient;
25 import org.apache.commons.net.time.TimeUDPClient;
26
27 /**
28 * This is an example program demonstrating how to use the TimeTCPClient and TimeUDPClient classes. It's very similar to the simple Unix rdate command. This
29 * program connects to the default time service port of a specified server, retrieves the time, and prints it to standard output. The default is to use the TCP
30 * port. Use the -udp flag to use the UDP port. You can test this program by using the NIST time server at 132.163.135.130 (warning: the IP address may change).
31 * <p>
32 * Usage: rdate [-udp] <hostname>
33 */
34 public final class rdate {
35
36 public static void main(final String[] args) {
37
38 if (args.length == 1) {
39 try {
40 timeTCP(args[0]);
41 } catch (final IOException e) {
42 e.printStackTrace();
43 System.exit(1);
44 }
45 } else if (args.length == 2 && args[0].equals("-udp")) {
46 try {
47 timeUDP(args[1]);
48 } catch (final IOException e) {
49 e.printStackTrace();
50 System.exit(1);
51 }
52 } else {
53 System.err.println("Usage: rdate [-udp] <hostname>");
54 System.exit(1);
55 }
56
57 }
58
59 public static void timeTCP(final String host) throws IOException {
60 final TimeTCPClient client = new TimeTCPClient();
61
62 // We want to timeout if a response takes longer than 60 seconds
63 client.setDefaultTimeout(60000);
64 client.connect(host);
65 System.out.println(client.getDate().toString());
66 client.disconnect();
67 }
68
69 public static void timeUDP(final String host) throws IOException {
70 try (TimeUDPClient client = new TimeUDPClient()) {
71 // We want to timeout if a response takes longer than 60 seconds
72 client.setDefaultTimeout(Duration.ofSeconds(60));
73 client.open();
74 System.out.println(client.getDate(InetAddress.getByName(host)).toString());
75 }
76 }
77
78 }