JAVA modify program

I have a multi client / server chat program that uses Diffie Hellman key exchange to encrypt messages. Entire Program provided, can you please make changes to have it run on the command line where and port number, P and Q, are entered in the servers command line. thank you. JAVA

DiffieServer.Java

package chat.server;
	import java.io.IOException;
	import java.net.ServerSocket;
	import java.net.Socket;
	import java.util.ArrayList;
	import chat.net.Connection;
	public class DiffieServer {
	private ServerSocket ssock;
	private ArrayList clients;
	public static void main(String args[]) {
	DiffieServer server = new DiffieServer(5050);
	server.start();
	}
	public DiffieServer(int port) {
	try {
	ssock = new ServerSocket(port);
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	public void start() {
	System.out.println("Server started...");
	clients = new ArrayList();
	BroadcastThread bct = new BroadcastThread();
	bct.start();
	try {
	while (true) {
	Socket csock = ssock.accept();
	Connection newClient = new Connection(csock);
	newClient.sendKey();
	clients.add(newClient);
	System.out.println("** New Client: " + csock.toString());
	}
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	private class BroadcastThread extends Thread {
	public void run() {
	while (true) {
	try {
	for (int i = 0; i < clients.size(); i++) {
	if (clients.get(i).hasMessage()) {
	String message = clients.get(i).getMessage();
	broadcastMessage(message);
	System.out.println(message);
	}
	}
	Thread.sleep(500);
	} catch (Exception e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	}
	private void broadcastMessage(String message) {
	for (int i = 0; i < clients.size(); i++) {
	clients.get(i).sendMessage(message);
	}
	}
	}
	}

DiffieClient.java

package chat.client;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.Socket;

import chat.net.Connection;

public class DiffieClient {

private Connection server;

public static void main(String args[]) {

DiffieClient client = new DiffieClient("192.168.1.139", 5051);

client.start();

}

public DiffieClient(String hostname, int port) {

try {

server = new Connection(new Socket(hostname, port));

} catch (IOException e) {

e.printStackTrace();

System.exit(1);

}

}

public void start() {

server.getKey();

BroadcastListener bcl = new BroadcastListener();

bcl.start();

BufferedReader sysin = new BufferedReader(new InputStreamReader(

System.in));

while (true) {

try {

server.sendMessage(sysin.readLine());

} catch (IOException e) {

e.printStackTrace();

System.exit(1);

}

}

}

private class BroadcastListener extends Thread {

public void run() {

try {

while (true) {

if (server.hasMessage()) {

System.out.println(server.getMessage());

}

Thread.sleep(500);

}

} catch (Exception e) {

e.printStackTrace();

System.exit(1);

}

}

}

}

Connection.java

package chat.net;
	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.io.PrintStream;
	import java.math.BigInteger;
	import java.net.Socket;
	import java.util.Random;
	import java.util.Scanner;
	public class Connection {
	private Socket socket;
	private BufferedReader br;
	private PrintStream ps;
	private BigInteger cipherKey;
	public Connection(Socket sck) {
	try {
	socket = sck;
	br = new BufferedReader(new InputStreamReader(
	socket.getInputStream()));
	ps = new PrintStream(socket.getOutputStream());
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	public void sendKey() {
	try {
	// send P and Q to client
	BigInteger p = new BigInteger("5");
	BigInteger q = new BigInteger("23");
	ps.println(p.toString() + " " + q.toString() + " ");
	/*System.out.println("--> SEND: P=" + p.toString() + " Q="
	+ q.toString());*/
	// receive public key from client
	BigInteger yourKey = new BigInteger(Integer.parseInt(br.readLine())
	+ "");
	//System.out.println("<-- RECEIVE: yourKey=" + yourKey.toString());
	// send public key to client
	Random rand = new Random();
	BigInteger privateKey = new BigInteger((rand.nextInt(100) + 1) + "");
	//System.out.println("(privateKey=" + privateKey.toString() + ")");
	BigInteger publicKey = p.modPow(privateKey, q);
	ps.println(publicKey.toString() + " ");
	//System.out.println("--> SEND: publicKey=" + publicKey.toString());
	// calculate cipher key
	cipherKey = yourKey.modPow(privateKey, q);
	//System.out.println("(cipherKey=" + cipherKey.toString() + ")");
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	public void getKey() {
	try {
	// receive P and Q from server
	Scanner ioscan = new Scanner(br.readLine());
	BigInteger p = new BigInteger(ioscan.nextInt() + "");
	BigInteger q = new BigInteger(ioscan.nextInt() + "");
	/*System.out.println("<-- RECEIVE: P=" + p.toString() + " Q="
	+ q.toString());*/
	// send public key to server
	Random rand = new Random();
	BigInteger privateKey = new BigInteger((rand.nextInt(100) + 1) + "");
	//System.out.println("(privateKey=" + privateKey.toString() + ")");
	BigInteger publicKey = p.modPow(privateKey, q);
	ps.println(publicKey.toString() + " ");
	//System.out.println("--> SEND: publicKey=" + publicKey.toString());
	// receive public key from server
	BigInteger yourKey = new BigInteger(Integer.parseInt(br.readLine())
	+ "");
	//System.out.println("<-- RECEIVE: yourKey=" + yourKey.toString());
	// calculate cipher key
	cipherKey = yourKey.modPow(privateKey, q);
	//System.out.println("(cipherKey=" + cipherKey.toString() + ")");
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	public boolean hasMessage() throws IOException {
	return br.ready();
	}
	public String getMessage() throws IOException {
	return decode(br.readLine());
	}
	public void sendMessage(String message) {
	ps.println(encode(message) + " ");
	}
	private String encode(String message) {
	message = message.toUpperCase();
	String encodedMessage = "";
	for (int i = 0; i < message.length(); i++) {
	char thisChar = message.charAt(i);
	if (thisChar >= 65 && thisChar <= 90) {
	int shiftValue = 1 + Integer.parseInt(cipherKey.mod(
	new BigInteger("26")).toString());
	//System.out.println("shiftValue = " + shiftValue);
	//System.out.println("thisChar (before) = " + thisChar);
	thisChar += shiftValue;
	if (thisChar > 90)
	thisChar -= 26;
	//System.out.println("thisChar (after) = " + thisChar);
	}
	//System.out.println("thisChar (appending) = " + thisChar);
	encodedMessage += thisChar;
	}
	return encodedMessage;
	}
	private String decode(String message) {
	message = message.toUpperCase();
	String decodedMessage = "";
	for (int i = 0; i < message.length(); i++) {
	char thisChar = message.charAt(i);
	if (thisChar >= 65 && thisChar <= 90) {
	int shiftValue = 1 + Integer.parseInt(cipherKey.mod(
	new BigInteger("26")).toString());
	thisChar -= shiftValue;
	if (thisChar < 65)
	thisChar += 26;
	}
	decodedMessage += thisChar;
	}
	return decodedMessage;
	}
	public void close() {
	try {
	ps.close();
	br.close();
	socket.close();
	} catch (IOException e) {
	e.printStackTrace();
	System.exit(1);
	}
	}
	}