native vs stringutils

ATest.java

package dan.langford;

import static org.testng.Assert.assertEquals;

import java.util.logging.Logger;

import org.apache.commons.lang.StringUtils;
import org.springframework.util.StopWatch;
import org.testng.annotations.Test;


public class ATest {

	private static Logger LOG = Logger.getAnonymousLogger();

	@Test
	public void f() {

		String input = "8789_25Langford_5_te.xml", actual = null, expected="8789_25Langford";

		// avoid logging,asserting inside active stopwatch
		StopWatch sw1 = new StopWatch(), sw2=new StopWatch();
		for (int i = 0; i++ < 10;) {

			sw1.start("java native api+"+1);
			for (int j = 0; j++ < 5000000;) {
				actual = input.substring(0, input.indexOf('_', input.indexOf('_')+1));
			}
			sw1.stop();
			assertEquals(actual, expected);

			sw2.start("apache commons stringutils+"+i);
			for (int k = 0; k++ < 5000000;) {
				actual = StringUtils.substring(input, 0,StringUtils.indexOf(input, '_',StringUtils.indexOf(input, '_')+1));
			}
			sw2.stop();
			assertEquals(actual, expected);

		}
		
		LOG.info("java native api avg "+ (sw1.getTotalTimeMillis() / sw1.getTaskCount()) );
		LOG.info("apache commons stringutils avg "+ (sw2.getTotalTimeMillis() / sw2.getTaskCount()) );
	}
}

output.log

Suites: 0 and:0
[TestNG] Running:
  C:\Users\danlangford.LDS\AppData\Local\Temp\testng-eclipse--2021784807\testng-customsuite.xml

Aug 10, 2012 3:09:01 PM dan.langford.ATest f
INFO: sw1 avg 182
Aug 10, 2012 3:09:01 PM dan.langford.ATest f
INFO: sw2 avg 198
PASSED: f

===============================================
    Default test
    Tests run: 1, Failures: 0, Skips: 0
===============================================


===============================================
Default suite
Total tests run: 1, Failures: 0, Skips: 0
===============================================

[TestNG] Time taken by [TestListenerAdapter] Passed:0 Failed:0 Skipped:0]: 0 ms
[TestNG] Time taken by org.testng.reporters.JUnitReportReporter@1342a80d: 8 ms
[TestNG] Time taken by org.testng.reporters.XMLReporter@29e97f9f: 13 ms
[TestNG] Time taken by org.testng.reporters.SuiteHTMLReporter@25595f51: 28 ms
[TestNG] Time taken by org.testng.reporters.EmailableReporter@6cb8: 4 ms
[TestNG] Time taken by org.testng.reporters.jq.Main@53ebd75b: 48 ms