How to find elapsed time/benchmark a Java method/code using Eclipse?

Question

I am trying to find a clean way to find elapsed time. In other words, I want to find the time it takes for a given section of code to get executed.

I know the following two approaches:-

1>

long start = System.nanoTime();
// Code to measure
long elapsedTime = System.nanoTime() - start;

2>

long start = System.currentTimeMillis();
// Code to measure
long elapsedTime = System.currentTimeMillis() - start;

But these two approaches are dirty in the sense I have to litter the original code with my benchmarking code and later when benchmarking is over I will have to remember to remove the code.

I am looking for a cleaner approach which is supported by Eclipse/any other IDE in which I mark the code that I want to benchmark just like we specify breakpoints and Eclipse shows me the elapsed time whenever that portion of code is reached.

Is there any such method available in Eclipse/any other IDE?

Answer 1

我推荐Perf4j perf4j.codehaus.org

Answer 2

Set a field at the top of your class

private static final boolean DEBUG_THIS=true;

then when you have lines you want to use, put them in like this:

if (DEBUG_THIS){
    Log.v("Tag","It took " + System.currentTimeMillis() - start + " ms");
    // perhpas some other debug code
}

Then when you are tired or done debugging, change the one line of code at the top

private static final boolean DEBUG_THIS=false;

you can leave all your debug code otherwise in place, there if you ever need it again, and costing you nothing in the running version.

Answer 3

You can write a JUnit Test for the code. The JUnit plug-in for Eclipse will show you the time it took to run the test.