How do I time a method's execution in Java?

Question

How do I get a method's execution time? Is there a Timer utility class for things like timing how long a task takes, etc?

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

Answer 1

To get a method's execution time use:

long startTime = System.nanoTime();

methodToTime();

long endTime = System.nanoTime();

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

Of course, the warnings about using the wall clock apply: influences of JIT-compilation, multiple, etc. Thus, you need to first execute the method a lot of times first, such that the JIT compiler does its work, and then recur this test various times and take the lowest execution time