This is a quick study of the relative performance of the typical DTO methods generated by Groovy 2.4.3 annotations, Scala 2.11.6 case classes, Kotlin 0.11.91.1 data classes, and Lombok, all running on Oracle Java 8u40. These tests use the Groovy indy jar and compile flag. The Groovy model object is decorated with @CompileStatic.
I'm impatient, so each benchmark is running with 20 warmups, 50 iterations, and 1 fork. The benchmark is sampling for average time in nanoseconds.
Benchmark Mode Cnt Score Error Units
EqualsBenchmark.equalsGroovy avgt 50 57.035 ± 2.883 ns/op
EqualsBenchmark.equalsKotlin avgt 50 29.544 ± 1.269 ns/op
EqualsBenchmark.equalsLombok avgt 50 30.019 ± 1.350 ns/op
EqualsBenchmark.equalsScala avgt 50 51.966 ± 2.416 ns/op
Note: @danielthomas went deep by decompiling and comparing the bytecodes of Kotlin and Lombok generated equals methods, and they are essentially identical.
Note 2: Groovy 2.3.9 scored over 1000 ns/op on equals() with a similar error margin as below.
Benchmark Mode Cnt Score Error Units
HashCodeBenchmark.hashCodeGroovy avgt 50 1337.638 ± 60.966 ns/op
HashCodeBenchmark.hashCodeKotlin avgt 50 63.097 ± 3.222 ns/op
HashCodeBenchmark.hashCodeLombok avgt 50 61.493 ± 2.885 ns/op
HashCodeBenchmark.hashCodeScala avgt 50 139.673 ± 6.056 ns/op
Benchmark Mode Cnt Score Error Units
ToStringBenchmark.toStringGroovy avgt 50 2990.375 ± 148.777 ns/op
ToStringBenchmark.toStringKotlin avgt 50 463.005 ± 16.999 ns/op
ToStringBenchmark.toStringLombok avgt 50 440.080 ± 18.320 ns/op
ToStringBenchmark.toStringScala avgt 50 753.451 ± 31.255 ns/op