Benchmark string concatenation (version 2)

StringConcat.java

package com.bluetornadosf.microbench;

import java.util.HashMap;

import org.apache.commons.lang3.RandomStringUtils;

import com.google.caliper.Runner;
import com.google.caliper.SimpleBenchmark;

public class StringConcat extends SimpleBenchmark {

	private final static int CONCATENATIONS = 5;

	private HashMap<Integer, String> strings = new HashMap<Integer, String>();

	@Override
	protected void setUp() throws Exception {
		super.setUp();
		strings.clear();
		for (int i = 0; i < CONCATENATIONS; i++) {
			String s = RandomStringUtils.randomAlphabetic(10);
			strings.put(i, s);
		}
	}

	/**
	 * Use '+' to concat strings
	 * @param reps
	 */
	public void timeStringAddition(int reps) {
		for (int n = 0; n < reps; n++) {
			String concat = strings.get(0) + strings.get(1) + strings.get(2) + strings.get(3) + strings.get(4);
		}
	}

	/**
	 * Use {@link StringBuilder} to concat strings
	 * @param reps
	 */
	public void timeStringBuilder(int reps) {
		for (int n = 0; n < reps; n++) {
			StringBuilder sb = new StringBuilder(100);
			String concat = sb.append(strings.get(0)).append(strings.get(1)).append(strings.get(2)).append(strings.get(3)).append(strings.get(4)).toString();
		}
	}

	/**
	 * Use {@link StringBuffer} to concat strings
	 * @param reps
	 */
	public void timeStringBuffer(int reps) {
		for (int n = 0; n < reps; n++) {
			StringBuffer sb = new StringBuffer(100);
			String concat = sb.append(strings.get(0)).append(strings.get(1)).append(strings.get(2)).append(strings.get(3)).append(strings.get(4)).toString();
		}
	}

	public static void main(String... args) throws Exception {
		Runner.main(StringConcat.class, args);
	}

}