java实现的登陆界面

public Login() throws IOException{

GetKeys();//获取文件登陆信息

User = new JTextField(15);
PassWord = new JPasswordField(15);
PassWord.setEchoChar('*');

JPanel p1 = new JPanel();
p1.add(new JLabel("姓名:"));
p1.add(User);
p1.add(new JLabel("密码:"));
p1.add(PassWord);

add(p1,BorderLayout.CENTER);
JPanel p2 = new JPanel();
JButton button = new JButton("确定");
button.addActionListener(new ActionListener()//登录监听器
{
@SuppressWarnings("deprecation")
public void actionPerformed(ActionEvent e)
{
String name = User.getText();
String password = PassWord.getText();
if(message.containsKey(name))//姓名正确
{
num = 3;//一个用户名有3次输入密码机会
if(message.get(name).equals(password))//密码正确
{
JOptionPane.showMessageDialog(Login.this, "登陆成功!");
System.exit(0);
}
else
{
num--;
if(num > 0)
{
JOptionPane.showMessageDialog(Login.this, "密码错误!还有"+num+"次机会");
PassWord.setText("");
}
else if(num == 0)
{
JOptionPane.showMessageDialog(Login.this, "登录3次失败程序关闭！");
System.exit(0);
}
}
}
else
{
JOptionPane.showMessageDialog(Login.this, "不存在该用户名");
User.setText("");
PassWord.setText("");
}

}
});
p2.add(button);

button = new JButton("取消");
button.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
p2.add(button);

add(p2,BorderLayout.SOUTH);
setLocation(400,200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setVisible(true);
}