StopWatch介绍

StopWatch类是Spring框架中用于测量代码执行时间的工具类，它提供了一系列属性来记录监测信息。

本文基于spring-boot-starter-web:2.2.2RELEASE版本。

源码：

public class StopWatch {
    private final String id;
    private boolean keepTaskList = true;
    private final List<StopWatch.TaskInfo> taskList = new LinkedList<>();
    private long startTimeMillis;
    @Nullable
    private String currentTaskName;
    @Nullable
    private StopWatch.TaskInfo lastTaskInfo;
    private int taskCount;
    private long totalTimeMillis;

	......方法略
	public static final class TaskInfo {

		private final String taskName;
	
		private final long timeNanos;
	}
}

StopWatch属性详解

StopWatch方法详解

StopWatch使用示例

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

        stopWatch.start("task1");
        System.out.println("当前任务名称："+stopWatch.currentTaskName());
        Thread.sleep(1000);
        stopWatch.stop();
        System.out.println("task1耗时毫秒："+stopWatch.getLastTaskTimeMillis());

        stopWatch.start("task2");
        System.out.println("当前任务名称："+stopWatch.currentTaskName());
        Thread.sleep(2000);
        stopWatch.stop();
        System.out.println("task2耗时毫秒："+stopWatch.getLastTaskTimeMillis());

        System.out.println("总任务数："+stopWatch.getTaskCount());
        System.out.println("总耗时毫秒："+stopWatch.getTotalTimeMillis());
        System.out.println("所有任务简要信息：\n"+stopWatch.shortSummary());
        System.out.println("所有任务详细信息：\n"+stopWatch.prettyPrint());
    }

输出：

当前任务名称：task1
task1耗时毫秒：1013
当前任务名称：task2
task2耗时毫秒：2014
总任务数：2
总耗时毫秒：3027
所有任务简要信息：
StopWatch '': running time = 3027555400 ns
所有任务详细信息：
StopWatch '': running time = 3027555400 ns
---------------------------------------------
ns         %     Task name
---------------------------------------------
1013462900  033%  task1
2014092500  067%  task2