    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
    018    package examples.unix;
    019
    020    import java.io.IOException;
    021    import java.net.InetAddress;
    022
    023    import org.apache.commons.net.time.TimeTCPClient;
    024    import org.apache.commons.net.time.TimeUDPClient;
    025
    026    /***
    027     * This is an example program demonstrating how to use the TimeTCPClient
    028     * and TimeUDPClient classes.  It's very similar to the simple Unix rdate
    029     * command.  This program connects to the default time service port of a
    030     * specified server, retrieves the time, and prints it to standard output.
    031     * The default is to use the TCP port.  Use the -udp flag to use the UDP
    032     * port.  You can test this program by using the NIST time server at
    033     * 132.163.135.130 (warning: the IP address may change).
    034     * <p>
    035     * Usage: rdate [-udp] <hostname>
    036     * <p>
    037     * <p>
    038     * @author Daniel F. Savarese
    039     ***/
    040    public final class rdate
    041    {
    042
    043        public static final void timeTCP(String host) throws IOException
    044        {
    045            TimeTCPClient client = new TimeTCPClient();
    046
    047            // We want to timeout if a response takes longer than 60 seconds
    048            client.setDefaultTimeout(60000);
    049            client.connect(host);
    050            System.out.println(client.getDate().toString());
    051            client.disconnect();
    052        }
    053
    054        public static final void timeUDP(String host) throws IOException
    055        {
    056            TimeUDPClient client = new TimeUDPClient();
    057
    058            // We want to timeout if a response takes longer than 60 seconds
    059            client.setDefaultTimeout(60000);
    060            client.open();
    061            System.out.println(client.getDate(InetAddress.getByName(host)).toString());
    062            client.close();
    063        }
    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: rdate [-udp] <hostname>");
    096                System.exit(1);
    097            }
    098
    099        }
    100
    101    }
    102