Classe Cliente

package br.com.uol.xpg.wyalves.chat2;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

@SuppressWarnings("serial")
public class Client extends JFrame implements ActionListener, KeyListener {

    private JTextArea text;
    private JTextField txtMsg;
    private JButton btnSend;
    private JButton btnExit;
    private JLabel lblHistoric;
    private JLabel lblMsg;
    private JPanel pnlContent;
    private Socket socket;
    private OutputStream out;
    private Writer outw;
    private BufferedWriter bfw;
    private JTextField txtIP;
    private JTextField txtPort;
    private JTextField txtName;

    public Client() {
        JLabel lblCheck = new JLabel("Verificar!");
        txtIP = new JTextField("127.0.0.1");
        txtPort = new JTextField("12345");
        txtName = new JTextField("Cliente");
        Object[] texts = { lblCheck, txtIP, txtPort, txtName };
        JOptionPane.showMessageDialog(null, texts);

        pnlContent = new JPanel();
        text = new JTextArea(10, 20);
        text.setEditable(false);
        text.setBackground(new Color(240, 240, 240));
        txtMsg = new JTextField(20);
        lblHistoric = new JLabel("Histórico");
        lblMsg = new JLabel("Mensagem");
        btnSend = new JButton("Enviar");
        btnSend.setToolTipText("Enviar Mensagem");
        btnExit = new JButton("Sair");
        btnSend.setToolTipText("Sair do Chat");

        btnSend.addActionListener(this);
        btnExit.addActionListener(this);
        btnSend.addKeyListener(this);
        btnExit.addKeyListener(this);

        JScrollPane scroll = new JScrollPane(text);
        text.setLineWrap(true);

        pnlContent.add(lblHistoric);
        pnlContent.add(scroll);
        pnlContent.add(lblMsg);
        pnlContent.add(txtMsg);
        pnlContent.add(btnExit);
        pnlContent.add(btnSend);
        pnlContent.setBackground(Color.LIGHT_GRAY);

        text.setBorder(BorderFactory.createEtchedBorder(Color.BLUE, Color.BLUE));
        txtMsg.setBorder(BorderFactory.createEtchedBorder(Color.BLUE, Color.BLUE));
        setTitle(txtName.getText());
        setContentPane(pnlContent);
        setLocationRelativeTo(null);
        setResizable(false);
        setSize(250, 300);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public void connect() {
        try {
            socket = new Socket(txtIP.getText(), Integer.parseInt(txtPort.getText()));
            out = socket.getOutputStream();
            outw = new OutputStreamWriter(out);
            bfw = new BufferedWriter(outw);
            bfw.write(txtName.getText() + "\r\n");
            bfw.flush();
        } catch (Exception e) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
        }
    }

    public void sendMessage(String msg) {
        try {
            if (msg.equals("Sair!")) {
                bfw.write("Desconectado \r\n");
                text.append("Desconectado \r\n");
            } else {
                bfw.write(msg + "\r\n");
                text.append(txtName.getText() + " diz -> " + txtMsg.getText() + "\r\n");
            }
            bfw.flush();
            txtMsg.setText("");
            txtMsg.getCursor();

        } catch (IOException e) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
        }
    }

    public void listen() {
        try {
            InputStream in = socket.getInputStream();
            InputStreamReader inr = new InputStreamReader(in);
            BufferedReader bfr = new BufferedReader(inr);
            String msg = "";

            while (!"Sair!".equalsIgnoreCase(msg)) {
                if (bfr.ready()) {
                    msg = bfr.readLine();
                    if (msg.equals("Sair")) {
                        text.append("O servidor caiu!\r\n");
                    } else {
                        text.append(msg + "\r\n");
                    }
                }
            }
        } catch (IOException e) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
        }
    }

    public void exit() {
        try {
            sendMessage("Sair");
            bfw.close();
            outw.close();
            out.close();
            socket.close();
        } catch (IOException e) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
        }
    }

    @Override
    public void actionPerformed(ActionEvent evt) {
        try {
            if (evt.getActionCommand().equals(btnSend.getActionCommand())) {
                sendMessage(txtMsg.getText());
            } else if (evt.getActionCommand().equals(btnExit.getActionCommand())) {
                exit();
            }
        } catch (Exception e) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
        }
    }

    @Override
    public void keyPressed(KeyEvent evt) {
        if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
            try {
                sendMessage(txtMsg.getText());
            } catch (Exception e) {
                Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, e);
            }
        }
    }

    @Override
    public void keyReleased(KeyEvent arg0) {
    }

    @Override
    public void keyTyped(KeyEvent arg0) {
    }

    public static void main(String[] args) {

        Client chat = new Client();
        chat.connect();
        chat.listen();
    }
}