Java：使用StopWatch统计程序执行耗时

依赖

注意：StopWatch并不是JDK自带的类，需要引入spring类库，这一点很多文章都没说

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-coreartifactId>
    <version>5.3.31version>
dependency>

导入类

import org.springframework.util.StopWatch;

使用示例

示例1：统计单任务耗时

package com.demo;


import org.springframework.util.StopWatch;

public class StopWatchDemo {
    public static void main(String[] args) throws InterruptedException {
        StopWatch stopWatch = new StopWatch();

        stopWatch.start();

        Thread.sleep(3);

        stopWatch.stop();

        double totalTimeSeconds = stopWatch.getTotalTimeSeconds();
        // 打印总耗时
        System.out.println(totalTimeSeconds);
    }
}

示例2：统计多任务耗时

package com.demo;


import org.springframework.util.StopWatch;

public class StopWatchDemo {
    public static void main(String[] args) throws InterruptedException {
        StopWatch stopWatch = new StopWatch();

        // 任务1
        stopWatch.start("任务1");

        Thread.sleep(300);

        stopWatch.stop();


        // 任务2
        stopWatch.start("任务2");

        Thread.sleep(300);

        stopWatch.stop();

        // 打印耗时
        System.out.println(stopWatch.prettyPrint());
    }
}

输出

StopWatch '': running time = 600378510 ns
---------------------------------------------
ns         %     Task name
---------------------------------------------
300221065  050%  任务1
300157445  050%  任务2