满天星

import java.applet.*;import java.awt.*;public class das extends java.applet.Applet implements Runnable{    Thread PaintThread;    public void init() {            }    public void start(){        PaintThread=new Thread(this);        PaintThread.start();    }    public void stop(){        PaintThread=null;    }    public void paint(Graphics g){        //变量定义及初始化        int x[], y[], ox, oy, i, j, R, r, w, h;        double a, inca, cura;        Color c;        int cr, cg, cb;        inca=2 * Math.PI / 5;        x=new int[10];        y=new int[10];        w=getSize().width;        h=getSize().height;        //五角星        for (i=0; i<50; i++){            //随机五角星特征            ox=(int)(Math.random() * w);            oy=(int)(Math.random() * w);            R=(int)(Math.random() * 50);            r=(int)(R / 2);            a=(int)(Math.random() * 2 * Math.PI / 5);            //计算顶点数据            for(j=0; j<10; j+=2){                cura=a + inca * (j / 2);                x[j]=ox + (int)(R * Math.sin(cura));                y[j]=oy + (int)(R * Math.cos(cura));                cura=cura + inca / 2;                x[j+1]=ox + (int)(r * Math.sin(cura));                y[j+1]=oy + (int)(r * Math.cos(cura));            }            cr=(int)(Math.random() * 255);            cg=(int)(Math.random() * 255);            cb=(int)(Math.random() * 255);            c=new Color(cr, cg, cb);            //画出五角星            g.setColor(c);            g.fillPolygon(x, y, 10);        }    }    public void run() {        while(PaintThread!=null){            repaint();            try{                Thread.sleep(125);            }            catch(InterruptedException E){ }        }    }}