TwoChat.java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
import javax.swing.border.EtchedBorder;

public class TwoChat extends javax.swing.JFrame {

    private static final long serialVersionUID = 1L;
    ServerSocket ss;
    Socket s;

    JTextField text = new JTextField();
    JButton send = new JButton();
    JTextArea messages = new JTextArea();
    PrintWriter pout;
    BufferedReader br;
    ActionListener al;
    String ipstring;
    boolean ready2send = false;
    TwoChat pt;
    boolean HorC; // host or client
    String cliOrServ;

    public TwoChat(boolean hostOrConnect, String ip) {
        ipstring = ip;

        // Frame setup
        setLayout(null);
        setSize(600, 550);
        setTitle("Client-Server Chat");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        add(text);
        text.setLocation(5, 5);
        text.setSize(getWidth() - 40 - 60, 30);
        text.setEnabled(false);

        add(send);
        send.setLocation(10 + text.getWidth(), text.getY());
        send.setText("Send");
        send.setSize(70, 30);

        add(messages);
        messages.setEditable(false);
        messages.setBorder(new EtchedBorder());
        messages.setLocation(5, text.getHeight() + text.getY() + 5);
        messages.setSize(getWidth() - 70, getHeight() - text.getY() - text.getHeight() - 100);

        // Send button action
        al = new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                ready2send = true;
            }
        };
        send.addActionListener(al);

        pt = this;
        HorC = hostOrConnect;
        if (HorC)
            cliOrServ = "\nClient: ";
        else
            cliOrServ = "\nServer: ";

        Messenger.start();
    }

    public static void main(String args[]) {
        int inp = JOptionPane.showConfirmDialog(null,
                "Do you want to host the chat?\nYes - Act as server\nNo - Act as client",
                "Want to host a chat?",
                JOptionPane.YES_NO_OPTION);

        if (inp == 0) {
            new TwoChat(true, null).setVisible(true);
        } else {
            String ipstring = JOptionPane.showInputDialog("Please Enter the IP Address :) ");
            try {
                InetAddress.getByName(ipstring);
                new TwoChat(false, ipstring).setVisible(true);
            } catch (Exception e) {
                JOptionPane.showMessageDialog(null, "Invalid or Unreachable IP");
            }
        }
    }

    Thread Messenger = new Thread() {
        public void run() {
            try {
                if (HorC) {
                    messages.setText("Waiting for an incoming connection.\nEnter my IP at client side.\nMy IP: "
                            + InetAddress.getLocalHost().getHostAddress());
                    ss = new ServerSocket(9999);
                    s = ss.accept();
                    s.setKeepAlive(true);
                } else {
                    messages.setText("Connecting to: " + ipstring + ":9999");
                    s = new Socket(InetAddress.getByName(ipstring), 9999);
                }

                text.setEnabled(true);
                pout = new PrintWriter(s.getOutputStream(), true);
                br = new BufferedReader(new InputStreamReader(s.getInputStream()));

                messages.setText(messages.getText() + "\nConnected to: " + s.getInetAddress().getHostAddress() + ":"
                        + s.getPort());

                while (true) {
                    if (ready2send == true) {
                        pout.println(text.getText());
                        messages.setText(messages.getText() + "\nMe: " + text.getText());
                        text.setText("");
                        ready2send = false;
                    }
                    if (br.ready()) {
                        messages.setText(messages.getText() + cliOrServ + br.readLine());
                    }
                    Thread.sleep(80);
                }
            } catch (Exception ex) {
                JOptionPane.showMessageDialog(pt, ex.getMessage());
                messages.setText("Cannot connect!");
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException ex1) {
                }
                System.exit(0);
            }
        }
    };
}