How can i benchmark method execution time in java?

Question

I have a program which i have myself written in java, but I want to test method execution times and get timings for specific methods. I was wondering if this is possible, by maybe somehow an eclipse plug-in? or maybe inserting some code?

I see, it is quite a small program, nothing more than 1500 lines, which would be better a dedicated tool or System.currentTimeMillis()?

Many thanks

Answer 1

You should use a profiler like

• jprofiler
• yourkit

They will easily integrate with any IDE and show whatever detail you need.

Of course these tools are complex and meant to be used to profile complex programs, if you need just some simple benchmarks I suggest you to use System.currentTimeMillis() or System.nanoTime() and calculate delta of millisecs between calls by yourself.

Answer 2

You can add this code and it will tell you how long the method took to execute.

long millisecondsStart = System.currentTimeMillis();
executeMethod();
long timeSpentInMilliseconds = System.currentTimeMillis() - millisecondsStart;

Answer 3

Other than using a profiler, a simple way of getting what you want is the following:

public class SomeClass{
   public void somePublicMethod()
   {
       long startTime = System.currentTimeMillis();
       someMethodWhichYouWantToProfile();
       long endTime = System.currentTimeMillis();
       System.out.println("Total execution time: " + (endTime-startTime) + "ms"); 
   }
 }

Answer 4

Using a profiler is better because you can find out average execution times and bottlenecks in your app.

I use VisualVM. slick and simple.

Answer 5

Jprofiler and yourkit are good, but cost money.

There is a free plugin for eclispe called TPTP (Test & Performance Tools Platform) That can give you code execution times. Here is a tutorial that a quick google search brought up. http://www.eclipse.org/articles/Article-TPTP-Profiling-Tool/tptpProfilingArticle.html