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Thread.sleep还是TimeUnit.SECONDS.sleep--使用TimeUnit

TimeUnit可读性更强

举例子，sleep时间为3秒。

Thread.sleep的写法

private final int SLEEP_TIME = 3 * 1000; //3 seconds

void sleepDemo() throws InterruptedException{

Thread.sleep(SLEEP_TIME);

}

TimeUnit的写法

void sleepDemo() throws InterruptedException{

TimeUnit.SECONDS.sleep(3);

}

比较--很明显TimeUnit可读性更强

效率上TimeUnit不落下风

示例代码

import java.util.concurrent.TimeUnit;public class TestSleep {    public static void main(String[] args) throws InterruptedException {        sleepByTimeUnit(10);        sleepByThread(10);    }    //使用 TimeUnit 睡 10s    private static void sleepByTimeUnit(int sleepTimes) throws InterruptedException {        long start = System.currentTimeMillis();        TimeUnit.SECONDS.sleep(10);        long end = System.currentTimeMillis();        System.out.println("Total time consumed by TimeUnit : " + (end - start));    }    //使用 Thread.sleep 睡 10s    private static void sleepByThread(int sleepTimes) throws InterruptedException {        long start = System.currentTimeMillis();        Thread.sleep(10 * 1000);        long end = System.currentTimeMillis();        System.out.println("Total time consumed by Thread.sleep : " + (end - start));    }}

打印结果

Total time consumed by TimeUnit : 10001

Total time consumed by Thread.sleep : 10015

分析

TimeUnit做了封装，但是相对于 Thread.sleep 效率仍然不落下风。

TimeUnit其他使用--时间转换工具

例子代码

import java.util.concurrent.TimeUnit;public class TimeUnitUseDemo {    public static void main(String[] args) {        long seconds = TimeUnit.HOURS.toSeconds(2);        System.out.println("Spend seconds:" + seconds);    }}