public class LoginCumReg implements ActionListener,KeyListener {
    private JFrame form;
    private JTextField txtunm;
    private JTextField txtnm;
    private JTextField txteml;
    private JButton cmdcreate;
    private JPasswordField txtpass;
    private JPasswordField txtpassreg;
    private JButton cmdok;
    private JLabel lblunm;
    private JLabel lblpass;
    private JLabel lbleml;
    private JLabel lblpassreg;
    private JLabel lblnm;
    private JPanel panel_1;
public LoginCumReg() {
    // construct components
    form = new JFrame("Sign Up");
    form.getContentPane().setFont(
            new Font("Plantagenet Cherokee", Font.BOLD, 18));
    txtunm = new JTextField(5);
    txtunm.addKeyListener(this);
    txtunm.setBounds(637, 55, 100, 25);
    txtnm = new JTextField(5);
    txtnm.setBounds(637, 228, 100, 25);
    txteml = new JTextField(5);
    txteml.setBounds(637, 264, 100, 25);
    cmdcreate = new JButton("Create Account");
    cmdcreate.setBounds(527, 350, 188, 25);
    txtpass = new JPasswordField(5);
    txtpass.setBounds(637, 91, 100, 25);
    txtpassreg = new JPasswordField(5);
    txtpassreg.setBounds(637, 300, 100, 25);
    cmdok = new JButton("OK");
    cmdok.setBounds(527, 139, 100, 25);
    lblunm = new JLabel("UserName");
    lblunm.setBounds(527, 55, 73, 25);
    lblpass = new JLabel("Password");
    lblpass.setBounds(527, 91, 100, 25);
    lbleml = new JLabel("Email ID");
    lbleml.setBounds(527, 264, 100, 25);
    lblpassreg = new JLabel("Password");
    lblpassreg.setBounds(527, 300, 100, 25);
    lblnm = new JLabel("Full Name");
    lblnm.setBounds(527, 228, 100, 25);

    // form.setResizable(false);

    // adjust size and set layout
    form.setPreferredSize(new Dimension(800, 450));

    form.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    form.getContentPane().setLayout(null);

    // add components
    form.getContentPane().add(txtunm);
    form.getContentPane().add(txtnm);
    form.getContentPane().add(txteml);
    form.getContentPane().add(cmdcreate);
    form.getContentPane().add(txtpass);
    form.getContentPane().add(txtpassreg);
    form.getContentPane().add(cmdok);
    form.getContentPane().add(lblunm);
    form.getContentPane().add(lblpass);
    form.getContentPane().add(lbleml);
    form.getContentPane().add(lblpassreg);
    form.getContentPane().add(lblnm);

    cmdcreate.setActionCommand("Create Account");
    cmdcreate.addActionListener(this);
    cmdok.setActionCommand("Login");

    JPanel panel = new JPanel();
    panel.setBounds(502, 29, 254, 154);
    panel.setFont(new Font("Palatino Linotype", Font.PLAIN, 14));
    panel.setBorder(new TitledBorder(new EtchedBorder(EtchedBorder.RAISED,
            null, null), "LOGIN", TitledBorder.LEADING, TitledBorder.TOP,
            null, null));
    panel.setBackground(SystemColor.controlHighlight);
    form.getContentPane().add(panel);

    panel_1 = new JPanel();
    panel_1.setBounds(500, 204, 254, 186);
    panel_1.setFont(new Font("Palatino Linotype", Font.PLAIN, 14));
    panel_1.setBorder(new TitledBorder(new EtchedBorder(
            EtchedBorder.RAISED, null, null), "SIGN UP",
            TitledBorder.LEADING, TitledBorder.TOP, null, null));
    panel_1.setBackground(SystemColor.controlHighlight);
    form.getContentPane().add(panel_1);

    JLabel lblNewLabel = new JLabel("New label");
    lblNewLabel.setBounds(91, 139, 286, 101);
    lblNewLabel.setIcon(new ImageIcon(
            "C:\\Users\\JAsh\\Desktop\\Projects\\JAsh.png"));
    form.getContentPane().add(lblNewLabel);

    JPanel panel_2 = new JPanel();
    panel_2.setBounds(77, 118, 315, 145);
    panel_2.setBorder(new EtchedBorder(EtchedBorder.RAISED,
            SystemColor.activeCaptionBorder, SystemColor.menu));
    panel_2.setBackground(SystemColor.controlHighlight);
    form.getContentPane().add(panel_2);
    cmdok.addActionListener(this);

    form.setResizable(false);
    form.pack();
    form.setVisible(true);
    System.out.println("const..");
}

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

@Override
public void actionPerformed(ActionEvent ae) {
    // TODO Auto-generated method stub

    if (ae.getActionCommand().equals("Create Account")) {
        new Registration(txtnm.getText(), txteml.getText(), new String(
                txtpassreg.getPassword()));
        form.setVisible(false);
    }

    if (ae.getActionCommand().equals("Login")) {
        try {
            if (txtunm.getText().equalsIgnoreCase("admin")
                    && new String(txtpass.getPassword()).equals("admin")) {
                form.setVisible(false);
                new Admin();
            } else {
                DataBase db = new DataBase();
                db.connect();
                String sql = "SELECT * FROM LOGIN WHERE USERNAME='"
                        + txtunm.getText() + "'";
                ResultSet rs = db.getDDL(sql);
                boolean found = false;
                while (rs.next()) {
                    if (rs.getString("Password").equals(
                            new String(txtpass.getPassword()))) {
                        found = true;
                        form.setVisible(false);
                        String name = rs.getString("FullName");
                        Session.startSession(txtunm.getText(), name);
                        new FacultyWelcome();
                    }
                }
                if (!found)
                    JOptionPane.showMessageDialog(new JFrame(),
                            "Invalid Credentials");
                db.close();
            }
        } catch (Exception e) {
        }
    }

}

@Override
public void keyPressed(KeyEvent arg0) {
    // TODO Auto-generated method stub
}

@Override
public void keyReleased(KeyEvent arg0) {
    // TODO Auto-generated method stub

}

@Override
public void keyTyped(KeyEvent arg0) {
    // TODO Auto-generated method stub
//  JOptionPane.showMessageDialog(new JFrame(), arg0.getKeyChar()+"-"+arg0.getKeyCode());

}

}

上面的代码可以在我朋友的笔记本电脑上完美运行，并在我的笔记本电脑上抛出此错误。我已经使用Java 7在Eclipse
Juno上运行了代码。我还在便携式计算机上测试并运行了许多Java程序，都运行良好。这是唯一出现此类错误的程序。这是我的最后一年的项目，我需要它可以在笔记本电脑上工作，如果有任何帮助，我将不胜感激