Java计时新姿势StopWatch的使用方法详解

public static void main(String[] args) {
  Long startTime = System.currentTimeMillis();
  // 你的业务代码
  Long endTime = System.currentTimeMillis();
  Long elapsedTime = (endTime - startTime) / 1000;
  System.out.println("该段总共耗时：" + elapsedTime + "s");
}

<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>${spring.version}</version>
</dependency>

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

    // 任务一模拟休眠3秒钟
    stopWatch.start("TaskOneName");
    Thread.sleep(1000 * 3);
    System.out.println("当前任务名称：" + stopWatch.currentTaskName());
    stopWatch.stop();

    // 任务一模拟休眠10秒钟
    stopWatch.start("TaskTwoName");
    Thread.sleep(1000 * 10);
    System.out.println("当前任务名称：" + stopWatch.currentTaskName());
    stopWatch.stop();

    // 任务一模拟休眠10秒钟
    stopWatch.start("TaskThreeName");
    Thread.sleep(1000 * 10);
    System.out.println("当前任务名称：" + stopWatch.currentTaskName());
    stopWatch.stop();

    // 打印出耗时
    System.out.println(stopWatch.prettyPrint());
    System.out.println(stopWatch.shortSummary());
    // stop后它的值为null
    System.out.println(stopWatch.currentTaskName()); 
    
    // 最后一个任务的相关信息
    System.out.println(stopWatch.getLastTaskName());
    System.out.println(stopWatch.getLastTaskInfo());
    
    // 任务总的耗时  如果你想获取到每个任务详情（包括它的任务名、耗时等等）可使用
    System.out.println("所有任务总耗时：" + sw.getTotalTimeMillis());
    System.out.println("任务总数：" + sw.getTaskCount());
    System.out.println("所有任务详情：" + sw.getTaskInfo());
}

public class StopWatch {
    /**
	 * 本实例的唯一 Id，用于在日志或控制台输出时区分的。
	 */
    private final String id;
    /**
	 * 是否保持一个 taskList 链表
	 * 每次停止计时时，会将当前任务放入这个链表，用以记录任务链路和计时分析
	 */
	private boolean keepTaskList = true;
   /**
	 * 任务链表
	 * 用来存储每个task的信息, taskInfo由taskName 和 totoalTime组成
	 */
    private final List<StopWatch.TaskInfo> taskList;
    /**
	 * 当前任务的开始时间
	 */
    private long startTimeMillis;
    /**
	 * 
	 */
    private boolean running;
    /**
	 * 当前任务名称
	 */
    private String currentTaskName;
    /**
	 * 最后一个任务的信息
	 */
    private StopWatch.TaskInfo lastTaskInfo;
    /**
	 * 任务总数
	 */
    private int taskCount;
    /**
	 * 程序执行时间
	 */
    private long totalTimeMillis;
    ...
}

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.6</version>
</dependency>

public static void main(String[] args) throws InterruptedException {
    //创建后立即start，常用
    StopWatch watch = StopWatch.createStarted();

    // StopWatch watch = new StopWatch();
    // watch.start();

    Thread.sleep(1000);
    System.out.println(watch.getTime());
    System.out.println("统计从开始到现在运行时间：" + watch.getTime() + "ms");

    Thread.sleep(1000);
    watch.split();
    System.out.println("从start到此刻为止的时间：" + watch.getTime());
    System.out.println("从开始到第一个切入点运行时间：" + watch.getSplitTime());


    Thread.sleep(1000);
    watch.split();
    System.out.println("从开始到第二个切入点运行时间：" + watch.getSplitTime());

    // 复位后, 重新计时
    watch.reset();
    watch.start();
    Thread.sleep(1000);
    System.out.println("重新开始后到当前运行时间是：" + watch.getTime());

    // 暂停 与 恢复
    watch.suspend();
    System.out.println("暂停2秒钟");
    Thread.sleep(2000);

    // 上面suspend，这里要想重新统计，需要恢复一下
    watch.resume();
    System.out.println("恢复后执行的时间是：" + watch.getTime());

    Thread.sleep(1000);
    watch.stop();

    System.out.println("花费的时间》》" + watch.getTime() + "ms");
    // 直接转成s
    System.out.println("花费的时间》》" + watch.getTime(TimeUnit.SECONDS) + "s");
}

long start = System.currentTimeMillis();      
......业务处理
System.out.println("耗时:" + (System.currentTimeMillis() - start) + "ms");

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

        StopWatch stopWatch = new StopWatch("任务耗时秒表工具");

        stopWatch.start("task1");
        Thread.sleep(1000);
        stopWatch.stop();
        System.out.println(stopWatch.getTotalTimeMillis());
        stopWatch.start("task2");
        Thread.sleep(3000);
        stopWatch.stop();
        //所有任务耗时时间
        System.out.println(stopWatch.getTotalTimeMillis());
        System.out.println(stopWatch.prettyPrint());

        StopWatch stopWatch2 = new StopWatch("任务耗时秒表工具2");
        stopWatch2.start("task3");
        Thread.sleep(3000);
        stopWatch2.stop();
        //所有任务耗时时间
        System.out.println(stopWatch2.getTotalTimeMillis());
        System.out.println(stopWatch2.prettyPrint());

    }