//【例8.1】  在Applet中畫月亮。

import java.awt.*;
import java.applet.Applet;

public class MoonApplet extends Applet
{
    public void paint(Graphics g)                //在Applet上繪圖
    {
        g.setColor(Color.red);
        g.drawString("The Moon",100,20);

        int x=0,y=0;                             //圓外切矩形左上角坐標
        x = this.getWidth() /4;
        y = this.getHeight() /4; 

        int diameter = Math.min(this.getWidth()/2, this.getHeight()/2);   //圓的直徑

        g.setColor(Color.yellow);
        g.fillOval(x,y,diameter,diameter);       //畫圓

        g.setColor(this.getBackground());        //設置為背景色
        g.fillOval(x-20,y-20,diameter,diameter); //畫圓
    }
}