Java GUI画圆。

package ydj;

import java.awt.*;

import javax.swing.*;

public class huayuan extends JFrame
{
    public huayuan()
    {
        mianban mb=new mianban();
        Container content=getContentPane();
        this.setVisible(true);
        this.setSize(400, 400);
        content.add(mb);
        mb.setBackground(Color.WHITE);
        mb.setForeground(Color.GREEN);
    }
    class mianban extends JPanel
    {
        public void paint(Graphics g)
        {
            super.paint(g);
            g.drawOval(500,100,100,100);        //第一层
            g.drawOval(300,200,100,100);        //第二层第一个
            g.drawOval(700,200,100,100);        //弟二层第二个
            g.drawOval(150,300,100,100);        //第三层第一个
            g.drawOval(400,300,100,100);        //第三层第二个
            g.drawOval(550,300,100,100);        //第三层第三个
            g.drawOval(800,300,100,100);        //第三层第四个
            g.drawOval(250,400,100,100);        //第三层第一个
            g.drawLine(510,175,390,225);
            g.drawLine(600,150,715,215);
            g.drawLine(310,275,150,300);
            //g.drawLine(300,200,400,300);

        }
    }
    public static void main(String args[])
    {
        huayuan c=new huayuan();
    }
}