Master Java Performance Timing with Spring and Apache StopWatch

Background

When developing Java applications, measuring the execution time of tasks is often needed. The naive approach of recording start and end timestamps works but becomes cumbersome for multiple sections of code.

Spring StopWatch Usage

The org.springframework.util.StopWatch class provides a convenient way to time sequential tasks with millisecond precision. It is suitable for single‑threaded code blocks.

public static void main(String[] args) throws InterruptedException {
    StopWatch stopWatch = new StopWatch();
    // Task 1 – sleep 3 seconds
    stopWatch.start("TaskOne");
    Thread.sleep(1000 * 3);
    stopWatch.stop();
    // Task 2 – sleep 10 seconds
    stopWatch.start("TaskTwo");
    Thread.sleep(1000 * 10);
    stopWatch.stop();
    // Task 3 – sleep 10 seconds
    stopWatch.start("TaskThree");
    Thread.sleep(1000 * 10);
    stopWatch.stop();
    System.out.println(stopWatch.prettyPrint());
    System.out.println(stopWatch.shortSummary());
    System.out.println(stopWatch.getLastTaskName());
    System.out.println(stopWatch.getLastTaskInfo());
    System.out.println("Total time: " + stopWatch.getTotalTimeMillis());
    System.out.println("Task count: " + stopWatch.getTaskCount());
    System.out.println("All tasks: " + stopWatch.getTaskInfo());
}

Key points:

The StopWatch is not thread‑safe; use separate instances for concurrent timing.

Only one task can be active at a time; you must stop a task before starting another.

Apache Commons Lang3 StopWatch Usage

The org.apache.commons.lang3.time.StopWatch offers similar functionality with additional features such as split, suspend, and resume.

public static void main(String[] args) throws InterruptedException {
    StopWatch watch = StopWatch.createStarted();
    Thread.sleep(1000);
    System.out.println("Elapsed: " + watch.getTime() + "ms");
    watch.split();
    System.out.println("Split time: " + watch.getSplitTime());
    watch.suspend();
    Thread.sleep(2000); // paused
    watch.resume();
    Thread.sleep(1000);
    watch.stop();
    System.out.println("Total time: " + watch.getTime() + "ms");
    System.out.println("Total seconds: " + watch.getTime(TimeUnit.SECONDS) + "s");
}

Important notes:

It supports split timing, suspension, and resumption.

After calling reset(), the stopwatch can be reused.

Conclusion

Using dedicated stopwatch utilities simplifies performance analysis and makes timing code more readable and maintainable compared to manual timestamp calculations. Choose Spring's StopWatch for simple sequential tasks and Apache's StopWatch when you need advanced features like split and suspend.

Source: blog.csdn.net/duleilewuhen/article/details/114379693