Java ActionEvent cast event source to JButton

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

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

class MyActionListener implements ActionListener {
  public void actionPerformed(ActionEvent e) {
    JButton source = (JButton) e.getSource();
    String buttonText = source.getText();
    JOptionPane.showMessageDialog(null, "You clicked" + buttonText);
  }//from   w w w  .j  a v  a2 s. c o  m
}

public class Main {
  public static void main(String[] args) {
    JFrame frame = new JFrame("ActionListener");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JButton button = new JButton("Register");
    button.addActionListener(new MyActionListener());
    frame.getContentPane().add(button);
    frame.pack();
    frame.setVisible(true);
  }
}