builder vs buffer

gistfile1.java

package com.binarybuffer.test.bufferbuilder;

import org.apache.commons.math3.stat.descriptive.StatisticalSummary;
import org.apache.commons.math3.stat.descriptive.SummaryStatistics;
import org.junit.Test;



/**
 * Unit test for simple App.
 */
public class PefromanceTest {
	
	private double executeAndMeasure(Runnable r, long times) {
		long startTime = System.nanoTime();
		
		for (long i = 0; i < times; i++) {
			r.run();
		}
		
		return (System.nanoTime() - startTime)/1000000000;
	}
	
	@Test
	public void test() {
		long interations = 50000000;
		long executions = 30;
		
		SummaryStatistics bufferStat = new SummaryStatistics();
		SummaryStatistics builderStat = new SummaryStatistics();
		
		for (int i = 0; i < executions; i++) {
			System.out.println("Doing round " + i);
			builderStat.addValue(executeAndMeasure(stringBuilder, interations));
			bufferStat.addValue(executeAndMeasure(stringBuffer, interations));
		}

		System.out.println(String.format("Builder: Mean %f Std: %f ", 
				builderStat.getMean(), 
				builderStat.getStandardDeviation()));
		
		System.out.println(String.format("Buffer : Mean %f Std: %f ", 
				bufferStat.getMean(), 
				bufferStat.getStandardDeviation()));
	}
	
	private Runnable stringBuffer = new Runnable() {
		
		public void run() {
			StringBuffer sb = new StringBuffer();
			sb.append("someString");
			sb.append(100);
			sb.append(1l);
			sb.append('a');
			
		}
	};
	
	private Runnable stringBuilder = new Runnable() {
		
		public void run() {
			StringBuilder sb = new StringBuilder();
			sb.append("someString");
			sb.append(100);
			sb.append(1l);
			sb.append('a');
			
		}
	};
}