How to use VisualVM to get the time each function costs

Question

VisualVM is a nice but a little complicated tool for me.

I wrote a class with many functions (in Eclipse). How can I get the information of how many time each function calls and the time they cost when during execution?

lfvv · Answer 1 · 2022-02-22T09:38:55.840

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It is actually simple. Run your program and it will automatically appear as a running process in the VisualVM Panel. Click on it, and go straight to the Sampler tab. Finally, click on CPU and you got it. There you can see the time each function takes.

edited Feb 22 '22 at 09:38

answered May 14 '15 at 18:49

lfvv

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This should be the accepted answer. The simplest solution to what OP wants to know. – Display Name May 21 '17 at 21:19
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This should be the acceptable answer. KISS principle. Direct answer instead of reading the tutorials at the other link above. – Venkatt Guhesan Mar 13 '18 at 19:29

Michal Borek · Answer 2 · 2013-05-09T08:26:16.257

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For exhaustive analysis need to use alternative tool, e.g. JProfiler.

According to what @TomasHurka says you can profile also with VisualVM (https://blogs.oracle.com/nbprofiler/entry/profiling_with_visualvm_part_1)

edited May 09 '13 at 08:26

answered May 08 '13 at 12:54

Michal Borek

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This is not correct. VisualVM can do a lot of other things beside memory analysis. – Tomas Hurka May 09 '13 at 08:17
Thanks @TomasHurka I haven't known that feature, added your advice to accepted answer for clarity. – Michal Borek May 09 '13 at 08:26

score 0 · Answer 3 · answered May 08 '13 at 13:03

This might be a little helpful for you..

Use Time Difference to calculate the execution by making a method return something.

  long before = System.currentTimeMillis();
  String responseFromMethod=methodCall(); // String value returned from method

  long totalResponseTime=((System.currentTimeMillis() - before )/1000);

You can keep a counter value for how many times a function is called.

For VisualVM you can use Eclipse MAT to analyze heapdump . It will explain where does your program needs improvement.

Thanks,

How to use VisualVM to get the time each function costs

3 Answers3

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