import java.io.*;
import java.net.*;
import java.util.*;
public class DatagramServer
{
    public static void main(String[] args) throws IOException
    {
        byte[] buf = new byte[256];
        DatagramSocket socket = new DatagramSocket (4456);
        // receive request
        DatagramPacket packet = new DatagramPacket (buf, buf.length);
        System.out.println ("Waiting for date request");
        socket.receive (packet);
        System.out.println ("Received date request");
        // Send Date & Time
        String dString = new Date().toString();
        buf = dString.getBytes();
// send the response to the client at "address" and "port"
        InetAddress address = packet.getAddress ();
        int port = packet.getPort ();

        packet = new DatagramPacket (buf, buf.length, address, port);
        socket.send (packet);
        System.out.println ("Sent date request");
        socket.close ();
    }
}

//////////////////////////////////////////////////////////////////////////////////////////


import java.io.*;
import java.net.*;
import java.util.*;
public class DatagramServer
{
    public static void main(String[] args) throws IOException
    {
        byte[] buf = new byte[256];
        DatagramSocket socket = new DatagramSocket (4456);
        // receive request
        DatagramPacket packet = new DatagramPacket (buf, buf.length);
        System.out.println ("Waiting for date request");
        socket.receive (packet);
        System.out.println ("Received date request");
        // Send Date & Time
        String dString = new Date().toString();
        buf = dString.getBytes();
// send the response to the client at "address" and "port"
        InetAddress address = packet.getAddress ();
        int port = packet.getPort ();

        packet = new DatagramPacket (buf, buf.length, address, port);
        socket.send (packet);
        System.out.println ("Sent date request");
        socket.close ();
    }
}


//////////////////////////////////////////////////////////////////////////////////////////////

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.io.*;
import java.net.*;

public class UDPDateClient extends UDPDateGUI
{
    public ButtonHandler bHandler;

    public UDPDateClient (String title)
    {
        super (title);
        bHandler = new ButtonHandler();
        sendButton.addActionListener( bHandler );
    }

    private class ButtonHandler implements ActionListener
    {
        public void actionPerformed (ActionEvent event)  //throws IOException
        {
            // get a datagram socket
            try
            {
                DatagramSocket socket = new DatagramSocket ();
                // send request
                byte[] buf = new byte[32];
                InetAddress address = InetAddress.getByName ("127.0.0.1");
                DatagramPacket packet = new DatagramPacket (buf, buf.length, address, 4455);
                System.out.println ("About to request date & time");
                socket.send(packet);
                System.out.println ("Sent request for date and time");
                // get response
                packet = new DatagramPacket (buf, buf.length);
                socket.receive (packet);
                System.out.println ("Received date & time");
                // display response
                String received = new String (packet.getData());
                System.out.println ("Remote Date and Time: " + received);
                socket.close ();
                rxArea.setText ("Remote Date and Time: " + received);
            }
            catch (IOException e)
            {
                System.err.println("Couldn't get I/O for the connection to: 194.81.104.118.");
                System.exit(1);
            }
        }
    }

    public void run () throws IOException
    {
    }

    public static void main(String[] args) //throws IOException
    {

        UDPDateClient f = new UDPDateClient ("Date Client Program");

        f.pack ();
        f.show ();
        try
        {
            f.run ();
        }
        catch (IOException e)
        {
            System.exit(1);
        }

    }

}


/////////////////////////////////////////////////////////////////////////////////////////////

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class UDPDateGUI extends JFrame
{
    public JButton sendButton;
    public JTextArea txArea, rxArea;
    public Container container;

    public UDPDateGUI (String title)
    {
        super (title);
        container = getContentPane();
        container.setLayout (new FlowLayout());
        //txArea = new JTextArea (6, 40);
        rxArea = new JTextArea (6, 40);
        sendButton = new JButton ("Send");
        //bHandler = new ButtonHandler ();
        //sendButton.addActionListener (bHandler);
        container.add (rxArea);
        //container.add (txArea);
        container.add (sendButton);
    }
}