import java.io.*;
import java.net.*;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class UDPServer
{
public static void main(String args[])
{
try
{
System.out.println("UDPSERVER");
DatagramSocket ds=new DatagramSocket(10000);
System.out.println("socket created");
DatagramPacket p1,p2;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
byte arr[]=new byte [255];
String input,output;
System.out.println("packet created");
do
{
arr=new byte[255];
p1=new DatagramPacket (arr,255);
ds.receive (p1);
arr=p1.getData ();
input=new String (arr);
System.out.print("Message from client \t");
System.out.println(input);
if(input.charAt (0)=='*')
{
break;
}
System.out.println("Enter your message");
output=br.readLine();
arr=output.getBytes();
p2 = new DatagramPacket (arr,arr.length,p1.getAddress(),p1.getPort());
ds.send(p2);
}while (true);
ds.close();
System.out.println("closed server");
}catch(Exception e)
{
System.out.println("ERROR :"+e);
}
}
}
-------------------------------------------------------------------------------
import java.io.*;
import java.net.*;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class UDPClient
{
public static void main(String args[])
{
try
{
System.out.println("UDPCLIENT");
DatagramSocket ds;
System.out.println("socket created");
DatagramPacket p1,p2;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
byte arr[]=new byte [255];
String input,output;
InetAddress i=InetAddress.getLocalHost();
output="Hi i am client, send me a message";
arr=output.getBytes();
p1=new DatagramPacket(arr,arr.length,i,10000);
ds=new DatagramSocket();
ds.send(p1);
System.out.println("packet created");
do
{
arr=new byte[255];
p1=new DatagramPacket (arr,255);
ds.receive (p1);
arr=p1.getData();
input=new String (arr);
System.out.print("Message from server \t");
System.out.println(input);
if(input.charAt(0)=='*')
{
break;
}
System.out.println("Enter your message");
output=br.readLine();
arr=new byte[255];
arr=output.getBytes();
p2=new DatagramPacket(arr,arr.length,i,10000);
ds.send(p2);
}while (true);
ds.close();
System.out.println("closed server");
}catch(Exception e)
{
System.out.println("ERROR :"+e);
}
}
}