线程休眠

每个对象都有1个锁，sleep不会释放锁

import java.text.SimpleDateFormat;
import java.util.Date;

public class TestThreadSleep2 {

    public static void main(String[] args) {
        Date date = new Date(System.currentTimeMillis());
        boolean flag = true;
        while (flag) {
            System.out.println(new SimpleDateFormat("HH:mm:ss").format(date));
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            date = new Date(System.currentTimeMillis());
        }

    }
}

学习视频:狂神说java