java 画 园 用java画圆

import java.awt.*; 
 import javax.swing.*; 
 public class DrawO extends JFrame{MyPanel pp = null;

public static void main(String[] args) {
    //创建对象
    DrawO dd = new DrawO();
}
//设置画布大小
public DrawO() {
    pp = new MyPanel();
    this.add(pp);
    this.setSize(400,400);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
}} 
 //设置图画类 
 class MyPanel extends JPanel { 
 //重写画画方法 
 public void paint(Graphics g) { 
 super.paint(g); 
 g.drawOval(200, 70, 20, 20); 
 g.drawOval(150, 70, 20, 20); 
 g.drawLine(150, 30, 100, 30); 
 g.drawRect(150, 30, 70, 40); 
 g.setColor(Color.GREEN); 
 g.fillRect(0, 130, 70, 70); 
 g.setColor(Color.RED); 
 g.fillRect(0, 130, 140, 70); 
 g.setColor(Color.blue); 
 g.fillRect(130, 130, 70, 70); 
 g.fillRect(200, 130, 70, 70); 
 g.setColor(Color.black); 
 g.fillRect(200, 130, 210, 70); 
 } 
 }