记录方法执行时间

Question

在java/groovy应用程序中,我正在使用org.slf4j.Logger 我喜欢记录方法执行时间并建议使用以下代码

def startTime
LOGGER.isDebugEnabled() {
    startTime = System.currentTimeMillis()
}

doSomething()

LOGGER.debug("Execution took {}ms", (System.currentTimeMillis() - startTime))

我认为这段代码很"难看".谁能提出更优雅的建议？

Answer 1

您可以使用此类来计算经过的时间.

public class StopWatch {

    /* Private Instance Variables */
    /** Stores the start time when an object of the StopWatch class is initialized. */
    private long startTime;

    /**
     * Custom constructor which initializes the {@link #startTime} parameter.
     */
    public StopWatch() {
        startTime = System.currentTimeMillis();
    }

    /**
     * Gets the elapsed time (in seconds) since the time the object of StopWatch was initialized.
     * 
     * @return Elapsed time in seconds.
     */
    public double getElapsedTime() {
        long endTime = System.currentTimeMillis();
        return (double) (endTime - startTime) / (1000);
    }
}

并像这样使用它:

public class SWTest {

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

        doSomething();

        LOGGER.debug("Execution took in seconds: ", (stopWatch.getElapsedTime());
    }
}

Answer 2

如果你想让代码看起来不那么难看:

更改

def startTime
LOGGER.isDebugEnabled() {
    startTime = System.currentTimeMillis()
}

至

def startTime = System.currentTimeMillis()

我不是isDebugEnabled这些衬里的粉丝.没有它,你不会看到任何性能差异.