    001    package examples.ntp;
    002
    003    /*
    004     * Licensed to the Apache Software Foundation (ASF) under one or more
    005     * contributor license agreements.  See the NOTICE file distributed with
    006     * this work for additional information regarding copyright ownership.
    007     * The ASF licenses this file to You under the Apache License, Version 2.0
    008     * (the "License"); you may not use this file except in compliance with
    009     * the License.  You may obtain a copy of the License at
    010     *
    011     *      http://www.apache.org/licenses/LICENSE-2.0
    012     *
    013     * Unless required by applicable law or agreed to in writing, software
    014     * distributed under the License is distributed on an "AS IS" BASIS,
    015     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    016     * See the License for the specific language governing permissions and
    017     * limitations under the License.
    018     */
    019
    020
    021    import java.io.IOException;
    022    import java.net.InetAddress;
    023
    024    import org.apache.commons.net.time.TimeTCPClient;
    025    import org.apache.commons.net.time.TimeUDPClient;
    026
    027    /***
    028     * This is an example program demonstrating how to use the TimeTCPClient
    029     * and TimeUDPClient classes.
    030     * This program connects to the default time service port of a
    031     * specified server, retrieves the time, and prints it to standard output.
    032     * See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A>
    033     * for details.  The default is to use the TCP port.  Use the -udp flag to
    034     * use the UDP port.
    035     * <p>
    036     * Usage: TimeClient [-udp] <hostname>
    037     * <p>
    038     ***/
    039    public final class TimeClient
    040    {
    041
    042        public static final void timeTCP(String host) throws IOException
    043        {
    044            TimeTCPClient client = new TimeTCPClient();
    045        try {
    046              // We want to timeout if a response takes longer than 60 seconds
    047              client.setDefaultTimeout(60000);
    048          client.connect(host);
    049              System.out.println(client.getDate());
    050        } finally {
    051              client.disconnect();
    052        }
    053        }
    054
    055        public static final void timeUDP(String host) throws IOException
    056        {
    057            TimeUDPClient client = new TimeUDPClient();
    058
    059            // We want to timeout if a response takes longer than 60 seconds
    060            client.setDefaultTimeout(60000);
    061            client.open();
    062            System.out.println(client.getDate(InetAddress.getByName(host)));
    063            client.close();
    064        }
    065
    066        public static final void main(String[] args)
    067        {
    068
    069            if (args.length == 1)
    070            {
    071                try
    072                {
    073                    timeTCP(args[0]);
    074                }
    075                catch (IOException e)
    076                {
    077                    e.printStackTrace();
    078                    System.exit(1);
    079                }
    080            }
    081            else if (args.length == 2 && args[0].equals("-udp"))
    082            {
    083                try
    084                {
    085                    timeUDP(args[1]);
    086                }
    087                catch (IOException e)
    088                {
    089                    e.printStackTrace();
    090                    System.exit(1);
    091                }
    092            }
    093            else
    094            {
    095                System.err.println("Usage: TimeClient [-udp] <hostname>");
    096                System.exit(1);
    097            }
    098
    099        }
    100
    101    }
    102