import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ImplementsListener extends JFrame implements ActionListener
{

	public static void main(String[] args) {
		JFrame frame = new ImplementsListener();
		frame.show();
	}

	ImplementsListener() {
		setTitle("Implements Listener");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400, 100);

		// The container frame will listen for events generated by this button
		btn.addActionListener(this);
		getContentPane().add(BorderLayout.CENTER, btn);
	}

	// this method is inherited from ActionListener and must be overridden
	public void actionPerformed(ActionEvent e) {
		btn.setText("Please do not click this button again");
	}

	JButton btn = new JButton("Please do not click this button");
}