timeclient.java

apache推出的net包

package examples.ntp;

/*
 * Copyright 2001-2005 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
import java.io.IOException;
import java.net.InetAddress;
import org.apache.commons.net.TimeTCPClient;
import org.apache.commons.net.TimeUDPClient;

/***
 * 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
 * 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 details.  The default is to use the TCP port.  Use the -udp flag to
 * use the UDP port.
 * <p>
 * Usage: TimeClient [-udp] <hostname>
 * <p>
 ***/
public final class TimeClient
{

    public static final void timeTCP(String host) throws IOException
    {
        TimeTCPClient client = new TimeTCPClient();
	try {
          // We want to timeout if a response takes longer than 60 seconds
          client.setDefaultTimeout(60000);
	  client.connect(host);
          System.out.println(client.getDate());
	} finally {
          client.disconnect();
	}
    }

    public static final void timeUDP(String host) throws IOException
    {
        TimeUDPClient client = new TimeUDPClient();

        // We want to timeout if a response takes longer than 60 seconds
        client.setDefaultTimeout(60000);
        client.open();
        System.out.println(client.getDate(InetAddress.getByName(host)));
        client.close();
    }

    public static final void main(String[] args)
    {

        if (args.length == 1)
        {
            try
            {
                timeTCP(args[0]);
            }
            catch (IOException e)
            {
                e.printStackTrace();
                System.exit(1);
            }
        }
        else if (args.length == 2 && args[0].equals("-udp"))
        {
            try
            {
                timeUDP(args[1]);
            }
            catch (IOException e)
            {
                e.printStackTrace();
                System.exit(1);
            }
        }
        else
        {
            System.err.println("Usage: TimeClient [-udp] <hostname>");
            System.exit(1);
        }

    }

}