休眠失效？

我按照老师的代码，敲完，运行，就直接一下子就输出了。

package com.imooc.runnable;

class MyThread implements Runnable{

@Override

public void run() {

for(int i=1;i<=100;i++) {

System.out.println(Thread.currentThread().getName()+"执行第"+i+"次！");

}

try {

Thread.sleep(5000);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

public class SleepDemo {

public static void main(String[] args) {

// TODO Auto-generated method stub

MyThread mt = new MyThread();

Thread t  = new Thread(mt);

t.start();

Thread t2 =new Thread(mt);

t2.start();

}

}