JMH int to String Benchmark

output.txt

> mvn clean package
> java -jar target/benchmark.jarar -r 10 -f 3
...
# Run complete. Total time: 00:51:31

Benchmark                             (n)   Mode  Cnt   Score   Error   Units
ToString.IntPlusString                  0  thrpt    9  25,904 ± 1,751  ops/us
ToString.IntPlusString                  1  thrpt    9  28,621 ± 1,873  ops/us
ToString.IntPlusString              -1000  thrpt    9  15,134 ± 3,197  ops/us
ToString.IntPlusString             200000  thrpt    9  12,207 ± 3,494  ops/us
ToString.IntPlusString         2147483647  thrpt    9   9,118 ± 1,187  ops/us
ToString.IntPlusString        -2147483648  thrpt    9  23,403 ± 4,224  ops/us
ToString.IntegerToString                0  thrpt    9  20,160 ± 3,844  ops/us
ToString.IntegerToString                1  thrpt    9  18,452 ± 2,015  ops/us
ToString.IntegerToString            -1000  thrpt    9  11,405 ± 0,831  ops/us
ToString.IntegerToString           200000  thrpt    9   8,810 ± 0,316  ops/us
ToString.IntegerToString       2147483647  thrpt    9   7,542 ± 0,624  ops/us
ToString.IntegerToString      -2147483648  thrpt    9  75,560 ± 2,767  ops/us
ToString.StringBuilderAppend            0  thrpt    9  26,582 ± 3,667  ops/us
ToString.StringBuilderAppend            1  thrpt    9  27,113 ± 3,415  ops/us
ToString.StringBuilderAppend        -1000  thrpt    9  14,386 ± 0,775  ops/us
ToString.StringBuilderAppend       200000  thrpt    9  11,085 ± 1,335  ops/us
ToString.StringBuilderAppend   2147483647  thrpt    9   7,125 ± 1,288  ops/us
ToString.StringBuilderAppend  -2147483648  thrpt    9  22,065 ± 2,776  ops/us
ToString.StringPlusInt                  0  thrpt    9  27,759 ± 2,075  ops/us
ToString.StringPlusInt                  1  thrpt    9  25,794 ± 2,020  ops/us
ToString.StringPlusInt              -1000  thrpt    9  15,098 ± 2,029  ops/us
ToString.StringPlusInt             200000  thrpt    9  11,955 ± 1,834  ops/us
ToString.StringPlusInt         2147483647  thrpt    9   6,938 ± 0,693  ops/us
ToString.StringPlusInt        -2147483648  thrpt    9  21,517 ± 1,594  ops/us
ToString.StringValueOf                  0  thrpt    9  16,575 ± 1,510  ops/us
ToString.StringValueOf                  1  thrpt    9  17,559 ± 2,895  ops/us
ToString.StringValueOf              -1000  thrpt    9  10,581 ± 0,856  ops/us
ToString.StringValueOf             200000  thrpt    9   9,488 ± 1,845  ops/us
ToString.StringValueOf         2147483647  thrpt    9   6,804 ± 0,256  ops/us
ToString.StringValueOf        -2147483648  thrpt    9  74,555 ± 4,836  ops/us

ToString.java

// class name and method names are not Java convention but readable
package net.eckenfels.jmhtest;

import java.util.concurrent.TimeUnit;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;

// default benchmark settings (can be overwritten on command line)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Warmup(iterations = 2, time = 2, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 3, time = 10, timeUnit = TimeUnit.SECONDS)
@Threads(value=1)
@Fork(value=3)
@State(Scope.Thread)
public class ToString
{
    // repeat all tests with the following integers
    @Param(value = {"0", "1", "-1000", "200000", ""+Integer.MAX_VALUE, ""+Integer.MIN_VALUE})
    int n;

    // JMH alloes you to return anything, this avoids optimizations
    @Benchmark
    public String StringValueOf()
    {
        return String.valueOf(n);
    }

    @Benchmark
    public String IntegerToString()
    {
        return Integer.toString(n);
    }

    @Benchmark
    public String StringBuilderAppend()
    {
        return new StringBuilder().append(n).toString();
    }

    @Benchmark
    public String StringPlusInt()
    {
        return "" + n;
    }

    @Benchmark
    public String IntPlusString()
    {
        return n + "";
    }
}

This is german locale, so , is the decimal seperator. Results are in operations per micro second.

Would you also test String.format()? Just curious :)