暑期学习JAVA，测试线程的休眠方法，找不到问题所在了，拜托各位大牛指点一下。

Question

import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.util.Random;
import javax.swing.JFrame;
public class SwingAndSleep extends Frame{
/**
*
*/
private static final long serialVersionUID = 1L;
private Thread t ;
private static Color[] color = {Color.BLACK,Color.BLUE,Color.CYAN,Color.GREEN,Color.ORANGE,Color.YELLOW,Color.RED,Color.PINK,Color.LIGHT_GRAY};
private static Random rand = new Random();
private static Color getC() {
return color[rand.nextInt(color.length)];
}

       public void SwingAndThread() {
           t = new Thread(new Runnable() {
            int x = 30;
            int y = 50;

            @Override
            public void run() {
                while(true) {
                    try{
                        Thread.sleep(100);
                    }catch (InterruptedException e) {
                        e.printStackTrace();// TODO: handle exception
                    }

                    Graphics graphics = getGraphics();
                    graphics.setColor(getC());
                    graphics.drawLine(x, y, 100, y++);
                    if(y>=80) {
                        y = 50;
                    }
                }

            }
        });
           t.start();
       }               
public static void main(String[] args) throws Exception {
           init(new JFrame(),100,100);
}
public static void init(JFrame frame ,int width, int height) {
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(width, height);
    frame.setVisible(true);
}

}

Answer 1

出啥问题了？能描述一下吗？