Java 定时器计数太快

Question

我想写一个计时器类，每秒计数到0，但似乎计数太快了。我究竟做错了什么？public class Eieruhr {    private int x;    public Eieruhr (int x){        this.x = x;    }    public static void main(String[] args){        Eieruhr eu = new Eieruhr(10);        eu.start();    }    public void start(){        for(int i = 0; i <= x; x--){            long s = System.nanoTime();            while( ((System.nanoTime() - s) / 100000000) < x);            System.out.println("tick - " + x);        }    }}

Answer 1

我建议你使用TimeUnit.SECONDS.sleep(1). 看一下代码：

public class Eieruhr {

    private int x;

    public Eieruhr(int x) {

        this.x = x;

    }

    public static void main(String[] args) throws InterruptedException {

        Eieruhr eu = new Eieruhr(10);

        eu.start();

    }

    public void start() throws InterruptedException {

        for (int i = 0; i < x; i++) {

            TimeUnit.SECONDS.sleep(1);

            System.out.println(new Date() + " tick - " + i);

        }

    }

}

输出：

Sat Oct 19 15:11:37 EEST 2019 tick - 0

Sat Oct 19 15:11:38 EEST 2019 tick - 1

Sat Oct 19 15:11:39 EEST 2019 tick - 2

Sat Oct 19 15:11:40 EEST 2019 tick - 3

Sat Oct 19 15:11:41 EEST 2019 tick - 4

Sat Oct 19 15:11:42 EEST 2019 tick - 5