Server GUI

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

public class GUIForServer extends JFrame implements ActionListener, WindowListener
{
    private JButton coexist;
    private JLabel question;
    private JTextArea messageArea, messageEvent;
    private JTextField portNumber;
    private JRadioButton tcp, udp;
    private Server server;
    private UDPServer udpserver;
    public GUIForServer(int port)
    {
        super("Messaging Server");
        server = null;

        JPanel north = new JPanel();
        north.add(new JLabel("Port number: "));
        portNumber = new JTextField("    " + port);
        north.add(portNumber);

        coexist = new JButton("Start Server");
        question = new JLabel("Please choose a connection type: ");
        tcp = new JRadioButton("TCP");
        udp = new JRadioButton("UDP");
        coexist.addActionListener(this);
        north.add(coexist);
        north.add(question);
        north.add(tcp);
        north.add(udp);
        add(north, BorderLayout.NORTH);

        JPanel center = new JPanel(new GridLayout(2,1));
        messageArea = new JTextArea(70,70);
        messageArea.setEditable(false);
        chatTextArea("Text area of messages that have been sent: \n");
        center.add(new JScrollPane(messageArea));

        messageEvent = new JTextArea(70,70);
        messageEvent.setEditable(false);
        eventTextArea("Log of events that has happened: \n");
        center.add(new JScrollPane(messageEvent));
        add(center);

        addWindowListener(this);
        setSize(600,600);
        setVisible(true);
    }

    public void chatTextArea(String str)
    {
        messageArea.append(str);
        messageArea.setCaretPosition(messageArea.getText().length() - 1);
    }

    public void eventTextArea(String str)
    {
        messageEvent.append(str);
        messageEvent.setCaretPosition(messageEvent.getText().length() - 1);
    }

    public void actionPerformed(ActionEvent ae)
    {
        if(tcp.isSelected())
        {
            if(server != null)
            {
                server.stop();
                server = null;
                portNumber.setEditable(true);
                coexist.setText("Start Server");
                return;
            }

            int port;
            try
            {
                port = Integer.parseInt(portNumber.getText().trim());
            }
            catch(Exception e)
            {
                eventTextArea("Invalid port number!");
                return;
            }

            server = new Server(port, this);

            new ServerThread().start();
            coexist.setText("Stop Server");
            portNumber.setEditable(false);
        }

        if(udp.isSelected())
        {
            if(udpserver != null)
            {
                portNumber.setEditable(true);
                coexist.setText("Start Server");
                return;
            }

            int port;
            try
            {
                port = Integer.parseInt(portNumber.getText().trim());
            }
            catch(Exception e)
            {
                eventTextArea("Invalid port number!");
                return;
            }

            udpserver = new UDPServer(this);

            //udpserver.main();

            coexist.setText("Stop Server");
            portNumber.setEditable(false);
        }

    }

    public static void main(String[] arg)
    {
        new GUIForServer(7257);
    }

    public void windowClosing(WindowEvent we)
    {

        if(server != null) {
            try {
                server.stop();
            }
            catch(Exception e) {
            }
            server = null;
        }

        dispose();
        System.exit(0);
    }

    public void windowClosed(WindowEvent we)
    {
    }

    public void windowOpened(WindowEvent we)
    {
    }

    public void windowIconified(WindowEvent we)
    {
    }

    public void windowDeiconified(WindowEvent we)
    {
    }

    public void windowActivated(WindowEvent we)
    {
    }

    public void windowDeactivated(WindowEvent we)
    {
    }

    public class ServerThread extends Thread
    {
        public void run()
        {
            server.start();
            coexist.setText("Start Server");
            portNumber.setEditable(true);
            eventTextArea("The server has crashed! \n");
            server = null;
        }
    }

    /*public class UDPServerThread extends Thread
    {
    public void run(){
    udpserver.start();
    coexist.setText("Start Server");
    portNumber.setEditable(true);
    eventTextArea("The server has crashed! \n");
    udpserver = null;
    }
    }
     */

}