Desenhar uma forma no java com paintComponent(Graphics g)

import javax.swing.<em>;

import java.awt.BorderLayout;

import java.awt.event.</em>;

public class SimpleGui1B implements ActionListener{

JButton button;

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

SimpleGui1B gui = new SimpleGui1B();

gui.go();

}

public void go(){
	JFrame frame = new JFrame();
	button = new JButton("click me");
	
	button.addActionListener(this);
	
	MyDrawPanel panel = new MyDrawPanel();
	frame.getContentPane().add(BorderLayout.NORTH, panel);
	
	frame.getContentPane().add(BorderLayout.SOUTH, button);
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.setSize(300, 300);
	
	frame.setVisible(true);
}


public void actionPerformed(ActionEvent event){
	button.setText("I've bee clicke");
}

import javax.swing.<em>;

import java.awt.</em>;

public class MyDrawPanel extends JPanel{

public void paintComponent(Graphics g){
	///super.paintComponent(g);
	
	setBackground(Color.black);
	g.setColor(Color.blue);
	g.fillRect(10, 10, 100, 100);

	g.fillOval(70, 70, 100, 100);*/
}