Thursday, July 12, 2012

Quick way to benchmark Java code

Don't you envy Ruby has the Benchmark module? Yes, there are many art and science go behind how to setup and run a good micro benchmark code, especially with the JVM. But many times you just want to see some result, quickly. There is actually a very groovy and quick way to bench mark Java code with gbench! Check this out:

import gbench.*
import org.apache.commons.lang.StringUtils
new BenchmarkBuilder().run {
    'jdk.String.split' {
        100.times{ "a b c d e f g h i j k l m n o p q r s t u v w x y z".split(" ") }
    'commons-lang.StringUtils.split' {
        100.times{ StringUtils.split("a b c d e f g h i j k l m n o p q r s t u v w x y z", " ") }

I ran above and get the following on my machine:

$ groovy benchmarkSplit.groovy
* Groovy: 2.0.0
* JVM: Java HotSpot(TM) Client VM (20.1-b02, Sun Microsystems Inc.)
    * JRE: 1.6.0_26
    * Total Memory: 15.5 MB
    * Maximum Memory: 247.5 MB
* OS: Windows XP (5.1, x86)

* Warm Up: Auto
* CPU Time Measurement: On

                                  user  system     cpu    real

jdk.String.split                663219       0  663219  693382
commons-lang.StringUtils.split  192721       0  192721  212359


  1. Hi, it seems that your example code compares same code (String.split) :)

  2. If you run it with the second test being StringUtils.split( ..., " " ), I get:

    jdk.String.split 284934
    commons-lang.StringUtils.split 106498

  3. Oops! Thank you for pointing it out Nagai and Tim. I guess after edited the post few times (in attempt to pretty it up), I messed it up.

    I have fixed the code sample and re-printed the result now. Thanks again!