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

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

public class Temp extends JFrame {
	static int WIDTH = 400;
	static int HEIGHT = 300;
	int buttonCount = 1;

	public Temp() {
		setLayout(new FlowLayout());
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		addButton();
		setSize(WIDTH, HEIGHT);
	}

	public void addButton() {
		JButton b = new JButton("Button " + buttonCount++);
		b.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				addButton();				
			}
		});
		add(b);
		revalidate();
	}
	
	public static void main(String[] args) {
		Temp t = new Temp();
		
		t.setVisible(true);
	}
	
}