Java简单方法实现子任务耗时统计

public class ScopedCallable<V> implements Callable<V> {

    private static final long NANO_TO_MS = 1_000_000L;

    /** 任务名称 */
    private final String taskName;

    /** 被包装的实际任务 */
    private final Callable<V> delegate;

    /** 任务提交时间 (纳秒) */
    private final long submitTime;

    /** 任务开始执行时间 (纳秒) */
    private long startTime;

    /** 任务执行结束时间 (纳秒) */
    private long endTime;
}

public ScopedCallable(String taskName, Callable<V> delegate) {
    this.taskName = Objects.requireNonNull(taskName);
    this.delegate = Objects.requireNonNull(delegate);
    this.submitTime = System.nanoTime();  // 记录提交时间
}

@Override
public V call() throws Exception {
    try {
        startTime = System.nanoTime();   // 记录开始时间
        return delegate.call();           // 执行实际任务
    } finally {
        endTime = System.nanoTime();      // 记录结束时间
        reportMetrics();                  // 上报监控指标
    }
}

/** 执行耗时 = 结束时间 - 开始时间 */
public long executionTime() {
    return endTime - startTime;
}

/** 等待耗时 = 开始时间 - 提交时间 */
public long waitTime() {
    return startTime - submitTime;
}

/** 总耗时 = 结束时间 - 提交时间 */
public long totalTime() {
    return endTime - submitTime;
}

private void reportMetrics() {
    long execMs = executionTime() / NANO_TO_MS;
    long waitMs = waitTime() / NANO_TO_MS;
    long totalMs = totalTime() / NANO_TO_MS;

    System.out.println("[" + taskName + "] 执行耗时: " + execMs + "ms");
    System.out.println("[" + taskName + "] 等待耗时: " + waitMs + "ms");
    System.out.println("[" + taskName + "] 总耗时: " + totalMs + "ms");
}

public static void main(String[] args) throws Exception {
    ExecutorService executor = Executors.newFixedThreadPool(2);

    // 提交包装后的任务
    Future<String> future = executor.submit(
        new ScopedCallable<>("queryDB", () -> {
            Thread.sleep(100);  // 模拟耗时操作
            return "result";
        })
    );

    System.out.println("结果: " + future.get());
    executor.shutdown();
}