001    package examples.ntp;
002    
003    /*
004     * Copyright 2001-2005 The Apache Software Foundation
005     *
006     * Licensed under the Apache License, Version 2.0 (the "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018     
019    import java.io.IOException;
020    import java.net.InetAddress;
021    import org.apache.commons.net.TimeTCPClient;
022    import org.apache.commons.net.TimeUDPClient;
023    
024    /***
025     * This is an example program demonstrating how to use the TimeTCPClient
026     * and TimeUDPClient classes.
027     * This program connects to the default time service port of a
028     * specified server, retrieves the time, and prints it to standard output.
029     * See <A HREF="ftp://ftp.rfc-editor.org/in-notes/rfc868.txt"> the spec </A>
030     * for details.  The default is to use the TCP port.  Use the -udp flag to
031     * use the UDP port.
032     * <p>
033     * Usage: TimeClient [-udp] <hostname>
034     * <p>
035     ***/
036    public final class TimeClient
037    {
038    
039        public static final void timeTCP(String host) throws IOException
040        {
041            TimeTCPClient client = new TimeTCPClient();
042            try {
043              // We want to timeout if a response takes longer than 60 seconds
044              client.setDefaultTimeout(60000);
045              client.connect(host);
046              System.out.println(client.getDate());
047            } finally {
048              client.disconnect();
049            }
050        }
051    
052        public static final void timeUDP(String host) throws IOException
053        {
054            TimeUDPClient client = new TimeUDPClient();
055    
056            // We want to timeout if a response takes longer than 60 seconds
057            client.setDefaultTimeout(60000);
058            client.open();
059            System.out.println(client.getDate(InetAddress.getByName(host)));
060            client.close();
061        }
062    
063        public static final void main(String[] args)
064        {
065    
066            if (args.length == 1)
067            {
068                try
069                {
070                    timeTCP(args[0]);
071                }
072                catch (IOException e)
073                {
074                    e.printStackTrace();
075                    System.exit(1);
076                }
077            }
078            else if (args.length == 2 && args[0].equals("-udp"))
079            {
080                try
081                {
082                    timeUDP(args[1]);
083                }
084                catch (IOException e)
085                {
086                    e.printStackTrace();
087                    System.exit(1);
088                }
089            }
090            else
091            {
092                System.err.println("Usage: TimeClient [-udp] <hostname>");
093                System.exit(1);
094            }
095    
096        }
097    
098    }
099