Kuangcp/JavaBase

package jmh;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;

import java.util.concurrent.TimeUnit;

/**
 * @author kuangcp on 2019-04-21 11:38 PM
 */
@BenchmarkMode(Mode.Throughput)
@Warmup(iterations = 2)
@Measurement(iterations = 2, time = 1)
@Threads(2)
@Fork(2)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
public class StringBuilderBenchmark {

    @Benchmark
    public void testStringAdd() {
        String a = "";
        for (int i = 0; i < 10; i++) {
            a += i;
        }
    }

    @Benchmark
    public void testStringBuilderAdd() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++) {
            sb.append(i);
        }
        sb.toString();
    }

    @Benchmark
    public void testStringBufferAdd() {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 10; i++) {
            sb.append(i);
        }
        sb.toString();
    }
}