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.ntp;
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. This program connects to the default time service port of a
29 * specified server, retrieves the time, and prints it to standard output. See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A> for
30 * details. The default is to use the TCP port. Use the -udp flag to use the UDP port.
31 * <p>
32 * Usage: TimeClient [-udp] <hostname>
33 * </p>
34 */
35 public final class TimeClient {
36
37 public static void main(final String[] args) {
38
39 if (args.length == 1) {
40 try {
41 timeTCP(args[0]);
42 } catch (final IOException e) {
43 e.printStackTrace();
44 System.exit(1);
45 }
46 } else if (args.length == 2 && args[0].equals("-udp")) {
47 try {
48 timeUDP(args[1]);
49 } catch (final IOException e) {
50 e.printStackTrace();
51 System.exit(1);
52 }
53 } else {
54 System.err.println("Usage: TimeClient [-udp] <hostname>");
55 System.exit(1);
56 }
57
58 }
59
60 public static void timeTCP(final String host) throws IOException {
61 final TimeTCPClient client = new TimeTCPClient();
62 try {
63 // We want to timeout if a response takes longer than 60 seconds
64 client.setDefaultTimeout(60000);
65 client.connect(host);
66 System.out.println(client.getDate());
67 } finally {
68 client.disconnect();
69 }
70 }
71
72 public static void timeUDP(final String host) throws IOException {
73 final TimeUDPClient client = new TimeUDPClient();
74
75 // We want to timeout if a response takes longer than 60 seconds
76 client.setDefaultTimeout(Duration.ofSeconds(60));
77 client.open();
78 System.out.println(client.getDate(InetAddress.getByName(host)));
79 client.close();
80 }
81
82 }