StopWatch介紹

StopWatch類是Spring框架中用于測量代碼執行時間的工具類，它提供了一系列屬性來記錄監測信息。

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

源碼：

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屬性詳解

StopWatch方法詳解

StopWatch使用示例

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

        stopWatch.start("task1");
        System.out.println("當前任務名稱："+stopWatch.currentTaskName());
        Thread.sleep(1000);
        stopWatch.stop();
        System.out.println("task1耗時毫秒："+stopWatch.getLastTaskTimeMillis());

        stopWatch.start("task2");
        System.out.println("當前任務名稱："+stopWatch.currentTaskName());
        Thread.sleep(2000);
        stopWatch.stop();
        System.out.println("task2耗時毫秒："+stopWatch.getLastTaskTimeMillis());

        System.out.println("總任務數："+stopWatch.getTaskCount());
        System.out.println("總耗時毫秒："+stopWatch.getTotalTimeMillis());
        System.out.println("所有任務簡要信息：\n"+stopWatch.shortSummary());
        System.out.println("所有任務詳細信息：\n"+stopWatch.prettyPrint());
    }

輸出：

當前任務名稱：task1
task1耗時毫秒：1013
當前任務名稱：task2
task2耗時毫秒：2014
總任務數：2
總耗時毫秒：3027
所有任務簡要信息：
StopWatch '': running time = 3027555400 ns
所有任務詳細信息：
StopWatch '': running time = 3027555400 ns
---------------------------------------------
ns         %     Task name
---------------------------------------------
1013462900  033%  task1
2014092500  067%  task2