Benchmark to concatenate 2 Strings

TwoStringsBenchmark.java

package org.sample;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;

import java.util.UUID;
import java.util.concurrent.TimeUnit;

@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
@Fork(1)
@State(Scope.Thread)
public class TwoStringsBenchmark {

    private String[] strings;

    @Setup
    public void setupTest(){
        strings = new String[2];
        strings[0] = UUID.randomUUID().toString().substring(0,10);
        strings[1] = UUID.randomUUID().toString().substring(0,10);
    }

    @Benchmark
    public void testPlus(Blackhole bh) {
        bh.consume(strings[0] + strings[1]);
    }

    @Benchmark
    public void testStringBuilder(Blackhole bh) {
        StringBuilder sb = new StringBuilder();
        sb.append(strings[0]).append(strings[1]);
        bh.consume(sb.toString());
    }

    @Benchmark
    public void testStringBuffer(Blackhole bh) {
        StringBuffer sb = new StringBuffer();
        sb.append(strings[0]).append(strings[1]);
        bh.consume(sb.toString());
    }

    @Benchmark
    public void testStringJoiner(Blackhole bh) {
        bh.consume(String.join("", strings[0], strings[1]));
    }

    @Benchmark
    public void testStringConcat(Blackhole bh) {
        bh.consume(strings[0].concat(strings[1]));
    }
}