Slip17. Write a Java program to
design a screen using Awt that will take a user name and password. If the user
name and password are not same, raise an Exception with appropriate message.
User can have 3 login chances only. Use clear button to clear the TextFields.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class InvalidPasswordException
extends Exception{}
public class Slip17 extends JFrame
implements ActionListener
{
JLabel name,pass;
JTextField nameText;
JPasswordField passText;
JButton login,end;
static int attempt=0;
public Slip17()
{
name=new
JLabel("Name:",JLabel.RIGHT);
pass=new
JLabel("Password:",JLabel.RIGHT);
nameText=new JTextField(20);
passText=new JPasswordField(20);
login=new
JButton("Login");
end=new JButton("END");
login.addActionListener(this);
end.addActionListener(this);
setLayout(new GridLayout(3,2));
add(name);
add(nameText);
add(pass);
add(passText);
add(login);
add(end);
setTitle("Login Check");
setSize(300,300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void
actionPerformed(ActionEvent ae)
{
JButton btn=(JButton)ae.getSource();
if(btn==end)
{
System.exit(0);
}
if(btn==login)
{
try
{
String user=nameText.getText();
String pass=new String(passText.getPassword());
if(user.compareTo(pass)==0)
{
JOptionPane.showMessageDialog(null,"LoginSuccessfull","Login",JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}
else
{
throw new
InvalidPasswordException();
}
}
catch(Exception e)
{
attempt++;
JOptionPane.showMessageDialog(null,"LoginFailed.","Login",JOptionPane.ERROR_MESSAGE);
nameText.setText("");
passText.setText("");
nameText.requestFocus();
if(attempt==3)
{
JOptionPane.showMessageDialog(null,"3
attempt over","Login",JOptionPane.ERROR_MESSAGE);
System.exit(0);
}
}
}
}
public static void main(String
args[])
{
new Slip17();
}
}
