How do I time the execution of a method in Java? Java Debug notes

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How do I time the execution of a method in Java?

How do I get the execution time of a method? Is there a Timer utility class that handles things like how long a timed task takes?

Most searches on Google return results for timers that schedule threads and tasks, which IS not what I want.

Answer:

$\color{purple} a lot of knowledge points, really need to write out just can master!! {~}$

There’s always the old-fashioned way:

long startTime = System.nanoTime();
methodToTime();
long endTime = System.nanoTime();

long duration = (endTime - startTime);  //divide by 1000000 to get milliseconds.
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Answer:

I accept the simple answer. Work for me.

long startTime = System.currentTimeMillis();

doReallyLongThing();

long endTime = System.currentTimeMillis();

System.out.println("That took " + (endTime - startTime) + " milliseconds");
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Answer:

Come on, guys! No one mentioned Guava’s (awesome) approach:

import com.google.common.base.Stopwatch;

Stopwatch timer = Stopwatch.createStarted();
//method invocation
LOG.info("Method took: " + timer.stop());
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Happily, stopwatch.toString () does a good job of choosing units of time to measure. That is, 38 ns will be printed if the value is small, and 5m 3s will be displayed if the value is long

Better:

Stopwatch timer = Stopwatch.createUnstarted();
for (...) {
   timer.start();
   methodToTrackTimeFor();
   timer.stop();
   methodNotToTrackTimeFor();
}
LOG.info("Method took: " + timer);
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Note: Google Guava requires Java 1.6+

The article translated from am2dgbqfb6mk75jcyanzabc67y ac4c6men2g7xr2a – stackoverflow – com. Translate. Goog/questions / 1…

The author suggests: I have always tested in this simple way

$\color{red} Welcome to my column StackOverFlow, I will filter the quality of the interview test!! {~}$

$\color{red} has the latest, elegant implementation, and I will also write my opinion on this question at the end of the article {~}$

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