線程休眠—sleep方法

Thread.sleep(ms)：當前線程進入Time—Wait狀態，並等待指定時間。

與wait的區別：wait只能用於同步塊中，wait釋放鎖。

class MyThread implements Runnable {
    public void run() {
        int i = 0;
        while(i < 6) {
            System.out.println(Thread.currentThread() + " a = " + i);
            i++;
            Thread.yield();
        }
    }
}
public class Demo1 {

    public static void main(String[] args) throws Exception {
        Thread t1 = new Thread(new MyThread(),"t1");
        Thread t2 = new Thread(new MyThread(),"t2");
        t1.start();
        t2.start();
        Thread.sleep(1);
        System.out.println(Thread.currentThread());
    }

}