001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.examples.unix;
019
020import java.io.IOException;
021import java.net.InetAddress;
022import java.time.Duration;
023
024import org.apache.commons.net.time.TimeTCPClient;
025import org.apache.commons.net.time.TimeUDPClient;
026
027/**
028 * 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
029 * 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
030 * 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).
031 * <p>
032 * Usage: rdate [-udp] <hostname>
033 */
034public final class rdate {
035
036    public static void main(final String[] args) {
037
038        if (args.length == 1) {
039            try {
040                timeTCP(args[0]);
041            } catch (final IOException e) {
042                e.printStackTrace();
043                System.exit(1);
044            }
045        } else if (args.length == 2 && args[0].equals("-udp")) {
046            try {
047                timeUDP(args[1]);
048            } catch (final IOException e) {
049                e.printStackTrace();
050                System.exit(1);
051            }
052        } else {
053            System.err.println("Usage: rdate [-udp] <hostname>");
054            System.exit(1);
055        }
056
057    }
058
059    public static void timeTCP(final String host) throws IOException {
060        final TimeTCPClient client = new TimeTCPClient();
061
062        // We want to timeout if a response takes longer than 60 seconds
063        client.setDefaultTimeout(60000);
064        client.connect(host);
065        System.out.println(client.getDate().toString());
066        client.disconnect();
067    }
068
069    public static void timeUDP(final String host) throws IOException {
070        try (TimeUDPClient client = new TimeUDPClient()) {
071            // We want to timeout if a response takes longer than 60 seconds
072            client.setDefaultTimeout(Duration.ofSeconds(60));
073            client.open();
074            System.out.println(client.getDate(InetAddress.getByName(host)).toString());
075        }
076    }
077
078}