DNSServer.java

import java.io.*;
import java.net.*;
public class DNSServer
{
	public static DatagramSocket ds;
	public static byte buffer[]=new byte[1024];
	public static int clientport=789, serverport=790;
	public static void main(String args[]) throws Exception
	{
		System.out.println("\n\n\tDNS Server using UDP\n");
		ds=new DatagramSocket(clientport);
		System.out.println("\tPress Ctrl+C to quit the program\n");
		BufferedReader dis=new BufferedReader(new InputStreamReader(System.in));
		InetAddress ia=InetAddress.getLocalHost();
		while(true)
		{
			DatagramPacket p=new DatagramPacket(buffer, buffer.length);
			ds.receive(p);
			String psx=new String(p.getData(), 0, p.getLength());
			System.out.println("Client: "+psx);
			InetAddress ib=InetAddress.getByName(psx);
			System.out.println("Server Output: "+ib);
			String str=dis.readLine();
			if(str.equals("end")) break;
			buffer=str.getBytes();
			ds.send(new DatagramPacket(buffer, str.length(), ia, serverport));
		}
	}
}