import java.awt.Color;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLayeredPane;
public class Main extends JFrame {
public Main() {
setSize(200, 150);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JLayeredPane lp = getLayeredPane();
JButton top = new JButton();
top.setBackground(Color.white);
top.setBounds(20, 20, 50, 50);
JButton middle = new JButton();
middle.setBackground(Color.gray);
middle.setBounds(40, 40, 50, 50);
JButton bottom = new JButton();
bottom.setBackground(Color.black);
bottom.setBounds(60, 60, 50, 50);
lp.add(middle, new Integer(2));
lp.add(top, new Integer(3));
lp.add(bottom, new Integer(1));
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}