Java JPasswordField

Java JPasswordField

JPasswordField class is a text component that allows single line text just like JTextField.It's used to enter password.

How to Declare JPasswordField class

This is how you declare java.swing.JPasswordField class.

[public class JPasswordField extends JTextField]

 JPasswordField used constructors

• JPasswordField()-creates a JPasswordField with null text.
• JPasswordField(String s)-creates a JPasswordField with a text.
• JPasswordField(int columns)-creates an empty JPasswordField with specified number of columns 
• JPasswordField(int columns, Strings)-creates a JPasswordField with specified number of columns and a text.

JPasswordField Example

[

import javax.swing.JFrame;

import javax.swing.JPasswordField;
import javax.swing.JLabel;
public class JPasswordFieldExample extends JFrame {

    JPasswordFieldExample()
    {
        super("JPasswordFieldExample");
        setLayout(null);
        setLocationRelativeTo(null);
        JLabel label=new JLabel("Password");
        JPasswordField pass=new JPasswordField();
        label.setBounds(20,100, 80,30);
        pass.setBounds(100,100,100,30);
        add(label);
        add(pass);
        setSize(400,400);
        setVisible(true);
    }
    public static void main(String args[])
    {
        new JPasswordFieldExample();
    }

}

]

Ouput

JPasswordField with ActionListener  Example 

[

import javax.swing.JFrame;
import javax.swing.JPasswordField;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.UIManager;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JOptionPane;
public class JPasswordFieldExample extends JFrame implements ActionListener{
    public JPasswordField pass;
    public JTextField user;
    JPasswordFieldExample()
    {
        super("JPasswordFieldExample");
        try        {
            UIManager.setLookAndFeel
                    ("com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel");
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        setLayout(null);
        setLocationRelativeTo(null);


        pass = new JPasswordField();

        pass.setBounds(100,75,100,30);
        JLabel label1=new JLabel("Username:");
        label1.setBounds(20,20, 80,30);
        JLabel label2=new JLabel("Password:");
        label2.setBounds(20,75, 80,30);
        JButton button = new JButton("Login");
        button.setToolTipText("Click here to login");
        button.addActionListener(this);
        button.setBounds(100,120, 80,30);
        user = new JTextField();
        user.setBounds(100,20, 100,30);

        add(label1);
        add(label2);
        add(user);
        add(pass);
        add(button);
        setSize(400,400);
        setVisible(true);
    }
    public static void main(String args[])
    {
        new JPasswordFieldExample();
    }
    public void actionPerformed(ActionEvent event)
    {
        String username=user.getText();
        String password= (String)pass.getText();
        JOptionPane.showMessageDialog(this, "Username Entered is="+username+
                        "\n Password is="+password,"Simple Login",
                JOptionPane.INFORMATION_MESSAGE);

    }
}

]

Output

Lessons to learn from Above Program

I have introduced several methods and swing components that i have talked about in my previous posts.These are.

• How to Add ActionListener to a JButton.
• How to getText from a JTextField.
• How to Use UIManager to set program Look and Feel.
• How to set JButton ToolTipText
• How to use JOptionPane.showMessageDialog

Main Lesson

The main lesson to learn today is how to create a simple login form with username and JPasswordField.

In my next lessons i will connect the login form with a database that verifies login credentials entered by the user.