5. Action Listeners

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import javax.swing.JOptionPane;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;



public class PasswordCreator extends JFrame{

    // Variables
    private JTextField text1;
    private JTextField text2;
    private JTextField text3;
    private JPasswordField pass;

    // Constructor
    PasswordCreator(){

        // Basics
        super("JFrame's title = Password Creation");
        setLayout(new FlowLayout());
        text1 = new JTextField(10);
        text2 = new JTextField("Name: ");
        text3 = new JTextField("Surname: ", 20);
        pass = new JPasswordField("My password: ");
        add(text1);
        add(text2);
        add(text3);
        add(pass);

        // More
        MyListener listener = new MyListener();
        text1.addActionListener(listener);
        text2.addActionListener(listener);
        text3.addActionListener(listener);
        pass.addActionListener(listener);
    }

    // *********************************************************************************
    // New class
    // *********************************************************************************
    private class MyListener implements ActionListener{

        // Includes only 1 method for listening to who was "pressed"
        public void actionPerformed(ActionEvent event){
            String str = "";
            if(event.getSource() == text1)
                str = String.format("Text field 1: %s", event.getActionCommand());
            else if(event.getSource() == text2)
                str = String.format("Text field 2: %s", event.getActionCommand());
            else if(event.getSource() == text3)
                str = String.format("Text field 3: %s", event.getActionCommand());
            else if(event.getSource() == pass)
                str = String.format("Pass field 1: %s", event.getActionCommand());

            JOptionPane.showMessageDialog(null, str);
        }
    }


    // *********************************************************************************
    // Main
    // *********************************************************************************
    public static void main(String args[]){
        PasswordCreator frame = new PasswordCreator();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setSize(600, 600);
        frame.setVisible(true);
    }

}