Java - Bidirectional data transfer using UDP

	import java.io.*;
	import java.net.*;

	public class UDPServer implements Runnable {
	    DatagramSocket socket = null;
	    DatagramPacket packetOut = null;
	    DatagramPacket packetIn = null;
	    BufferedReader readFromKeyBoard = null;
	    byte[] dataIn;
	    byte[] dataOut;

	    public UDPServer() {
	        try {
	            readFromKeyBoard = new BufferedReader(
	                new InputStreamReader(System.in));
	            dataIn = new byte[1024];
	            dataOut = new byte[1024];
	            socket = new DatagramSocket(997);

	            new Thread(this).start();

	            InetAddress inetAddress = InetAddress.getLocalHost();
	            while (true) {
	                String message = readFromKeyBoard.readLine();
	                dataIn = message.getBytes();
	                packetOut = new DatagramPacket(dataIn, message.length(), inetAddress, 999);
	                socket.send(packetOut);
	            }
	        } catch (Exception exp) {
	            exp.printStackTrace();
	        }
	    }

	    public void run() {
	        try {
	            while (true) {
	                packetIn = new DatagramPacket(dataOut, dataOut.length);
	                socket.receive(packetIn);
	                String message = new String(packetIn.getData(), 0, packetIn.getLength());
	                System.out.println(message);
	            }
	        } catch (Exception exp) {
	            exp.printStackTrace();
	        }
	    }

	    public static void main(String[] args) {
	        new UDPServer();
	    }
	}

	import java.io.*;
	import java.net.*;

	public class UDPClient implements Runnable {
	    DatagramSocket socket = null;
	    DatagramPacket packetOut = null;
	    DatagramPacket packetIn = null;
	    BufferedReader readFromKeyBoard = null;
	    byte[] dataIn;
	    byte[] dataOut;

	    public UDPClient() {
	        try {
	            readFromKeyBoard = new BufferedReader(
	                new InputStreamReader(System.in));
	            dataIn = new byte[1024];
	            dataOut = new byte[1024];
	            socket = new DatagramSocket(999);

	            new Thread(this).start();

	            InetAddress inetAddress = InetAddress.getLocalHost();
	            while (true) {
	                String message = readFromKeyBoard.readLine();
	                dataIn = message.getBytes();
	                packetOut = new DatagramPacket(dataIn, message.length(), inetAddress, 997);
	                socket.send(packetOut);
	            }
	        } catch (Exception exp) {
	            exp.printStackTrace();
	        }
	    }

	    public void run() {
	        try {
	            while (true) {
	                packetIn = new DatagramPacket(dataOut, dataOut.length);
	                socket.receive(packetIn);
	                String message = new String(packetIn.getData(), 0, packetIn.getLength());
	                System.out.println(message);
	            }
	        } catch (Exception exp) {
	            exp.printStackTrace();
	        }
	    }

	    public static void main(String[] args) {
	        new UDPClient();
	    }
	}