package show;

    import java.awt.Color;
	import java.awt.Frame;
	import java.awt.Graphics;
	import java.awt.Panel;

public class show1 {
	
	    public static void main(String[] args){
	          Frame w = new Frame();//创建一个面板
	          w.setSize(800, 600);//设置面板大小
	          w.setBackground(Color.black);//设置背景颜色
	          MyJPanel p = new MyJPanel();//创建了一个画布对象
	          w.add(p);
	          Thread t = new Thread(p);//创建一个线程
	          t.start();//启动线程
	          w.setVisible(true);//显示面板

	    }
	}
	@SuppressWarnings("serial")
	class MyJPanel extends Panel implements Runnable{
	    int[] x = new int[100];
	    int[] y = new int[100];
	    int[] y1 = new int[100];
	    public MyJPanel(){
	        for(int i=0;i<100;i++){
	            x[i]=this.randomNum(800);
	            y[i]=this.randomNum(600);
	        }

	}

	    public void paint(Graphics g){
	        g.setColor(Color.yellow);
	        g.fillOval(600, 70, 130, 130);
	        g.setColor(Color.black);
	        g.fillOval(550, 50, 130, 130);
	        g.setColor(Color.white);
	        for(int i =0;i<100;i++){
	            g.drawString("*", x[i], y[i]);
	            for (int j = -1; j < y1[i]; j++) {
	                g.drawString("*", x[i], 600-j*3);
	            }
	        }
	    } 

	    public void run(){
	        while(true){
	            for (int i = 0; i < y.length; i++) {
	                if(y[i]<=600){
	                    y[i]++;
	                }else{
	                    y1[i]++;
	                    y[i] = 0;
	                }
	            }
	            repaint();
	            try {
	                Thread.sleep(10);
	            } catch (InterruptedException e) {
	                // TODO Auto-generated catch block
	                e.printStackTrace();
	            }
	        }
	    }
	    //随机数生成
	    public int randomNum(int a){
	        return (int)(Math.random()*a);
	    }
	}