Compate Apache Common Lang StringUtils split performance with Google Guava Splitter split method.

StringUtilsTest.java

package bausteine;

import com.google.common.base.Splitter;
import org.apache.commons.lang.RandomStringUtils;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.util.StopWatch;
import org.springframework.util.StringUtils;

import java.text.NumberFormat;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.regex.Pattern;

import static java.lang.Runtime.getRuntime;
import static org.junit.Assert.*;

public class StringUtilsTest
{

    static int testDataCount = 5000;

    static int testDataStringSize = 10000;

    static List<String> testData = new LinkedList<String>();
    static List<Integer> testDataSize= new LinkedList<Integer>();

    static StopWatch stopWatch = new StopWatch();

    @BeforeClass
    public static void generateTestData() {
        for(int i=0; i < testDataCount; i++){
            String data = RandomStringUtils
              .random(testDataStringSize, "ABCDEFGHIJKLMNOPQRSTUVXYZ,");
            
            // cleanup for StringUtils.split()
            data=data.replace(",,", ",x,");
            if( data.endsWith(",") ) {
              data = data.substring(0,data.length()-1);
            }
            
            testData.add(data);
            testDataSize.add(data.split(",").length);
        }
    }

    @AfterClass
    public static void printTestSummery(){
        System.out.println(stopWatch.prettyPrint());
    }

    @Test
    public void javaSplit() throws Exception {
      stopWatch.start("javaSplit");
      Pattern p = Pattern.compile(",");
      Iterator<Integer> ref = testDataSize.iterator();
      for(String data: testData){
        String[] elements = p.split(data);
        assertEquals((int)ref.next(),elements.length);
        for (String element : elements) {
          assertTrue(element.length() < testDataStringSize);
        }
      }
      stopWatch.stop();
    }
    
    @Test
    public void apacheCommonLangSplit() throws Exception {
        stopWatch.start("Apache Common Lang Split");
        Iterator<Integer> ref = testDataSize.iterator();
        for(String data: testData){
            String[] elements = StringUtils.split(data, ",");
            int count = 1;
            while(elements!=null) {
              String part = elements[0];
              assertTrue(part.length() < testDataStringSize);
              
              String rest = elements[1];
              elements = StringUtils.split(rest, ",");
              count ++;
            }
            assertEquals(data,(int)ref.next(), count);
        }
        stopWatch.stop();
    }

    @Test
    public void guavaSplitterSplit() throws Exception {
        stopWatch.start("Google Guava Splitter");
        Splitter spiltter = Splitter.on(",");
        Iterator<Integer> ref = testDataSize.iterator();
        for(String data: testData){
            Iterable<String> elements = spiltter.split(data);
            int count = 0;
            for (String element : elements) {
                count++;
                assertTrue(element.length() < testDataStringSize);
            }
            assertEquals((int)ref.next(),count);
        }
        stopWatch.stop();
    }

}