jmh-benchmark-demo

Java Microbenchmark Harness (JMH) that runs with Junit and Maven.

Project is about how to run JMH benchmark tests from test scope with junit and maven.

It is recommended to run JMH not from your tests but directly from different main method code. Unit-tests and other IDE interferes with the measurements.

If your measurements will be in second / minutes /hours or longer than running the benchmarks from tests will not affect so hugely your benchmark results and you can use solution in this demo.

If your measurements will be in milliseconds / microseconds / nanoseconds ... run your benchmarks rather from main code and not from your tests to have better measurements.

Java Microbenchmark Harness Integration

Integration and usage of JMH is really easy. Just take a look at pom.xml and SampleBenchmarkTest.

Run

you can run test with your IDE also with maven

mvn clean test

Results after all benchmark ends

# Run complete. Total time: 00:00:07

Benchmark                   Mode  Cnt   Score   Error  Units
SampleBenchmarkTest.newWay  avgt    2   8.462          ms/op
SampleBenchmarkTest.oldWay  avgt    2  11.676          ms/op
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 7.839 sec

How it works

Tests fail if the average time is bigger than set 100 milliseconds. You can check and assert of course more atributes from results.

Conclusion

Dont use this demo if your benchmarks are really "micro". If not it is nice solution to have.

For some is maybe not good choice to have benchmarks in test maven lifecycle. If you wish take benchmarking from maven test phase you can create maven profile and and run benchmarks separately. See please jmh-benchmark-in-profile-demo