java split benchmark

Split.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.StringTokenizer;

public class Split {

	private static String string = "a/b/c/d/e/f/g/h/i/j/asd/asdas/dasdjasodjoa/sjd/oajs/djoasjd/as/odj/jaowdj/oajw/odj/aojwd/oja/owjd/oja/wjdoja/wdj/awjdojaw/odj/oawjd/oja/wjdoawjdojaw/d/dff";

	public static String[] split_tskuzzy(String s, char delimeter) {
		char[] c = s.toCharArray();
		LinkedList<String> ll = new LinkedList<String>();
		int index = 0;

		for (int i = 0; i < c.length; i++) {
			if (c[i] == delimeter) {
				ll.add(s.substring(index, i));
				index = i + 1;
			}
		}

		String[] arr = new String[ll.size()];
		Iterator<String> iter = ll.iterator();
		index = 0;

		for (index = 0; iter.hasNext(); index++)
			arr[index] = iter.next();

		return arr;

	}

	public static String[] split_tskuzzy2(String s, char delimeter) {
		ArrayList<String> ll = new ArrayList<String>();
		int index = 0;
		for (int i = 0; i < s.length(); i++) {
			if (s.charAt(i) == delimeter) {
				ll.add(s.substring(index, i));
				index = i + 1;
			}
		}
		
		if(index!=s.length())
			ll.add(s.substring(index, s.length()));
			
		return ll.toArray(new String[ll.size()]);

	}

	public static String[] split_banthar(String s, char delimeter) {

		int count = 1;

		for (int i = 0; i < s.length(); i++)
			if (s.charAt(i) == delimeter)
				count++;

		String[] array = new String[count];

		int a = -1;
		int b = 0;

		for (int i = 0; i < count; i++) {

			while (b < s.length() && s.charAt(b) != delimeter)
				b++;

			array[i] = s.substring(a+1, b);
			a = b;
			b++;
			
		}

		return array;

	}

	public static void main(String[] args) {

		int n=1000000;

		long start;

		start = System.currentTimeMillis();
		for (int i = 0; i < n; i++)
			split_banthar(string, '/');
		System.out.println("split_banthar: " + (System.currentTimeMillis() - start));

		start = System.currentTimeMillis();
		for (int i = 0; i < n; i++)
			split_tskuzzy(string, '/');
		System.out.println("split_tskuzzy: " + (System.currentTimeMillis() - start));
		
		start = System.currentTimeMillis();
		for (int i = 0; i < n; i++)
			split_tskuzzy2(string, '/');
		System.out.println("split_tskuzzy2: " + (System.currentTimeMillis() - start));
		
		start = System.currentTimeMillis();
		for (int i = 0; i < n; i++)
			string.split("/");
		System.out.println("string.split: " + (System.currentTimeMillis() - start));


		start = System.currentTimeMillis();
		for (int i = 0; i < n; i++) {
			StringTokenizer s = new StringTokenizer(string, "/");
			while (s.hasMoreElements())
				s.nextElement();
		}
		System.out.println("StringTokenizer: " + (System.currentTimeMillis() - start));

	}

}

Results:

$ /opt/jdk1.6.0_32/bin/java Split
split_banthar: 1809
split_tskuzzy: 2964
split_tskuzzy2: 2391
string.split: 4116
StringTokenizer: 2879

$ /opt/jre1.7.0_03/bin/java Split
split_banthar: 1835
split_tskuzzy: 3168
split_tskuzzy2: 2435
string.split: 2569
StringTokenizer: 2748

In Java 7, the string.split is much faster.

Java 1.8.0_91 from Eclipse in Win 10 and with i5 processor:

split_banthar: 681
split_tskuzzy: 692
split_tskuzzy2: 764
string.split: 740
StringTokenizer: 757

Results in Java 1.8.0_144 Linux Mint i3 6GB Ram (in sorted order):

split_tskuzzy: 1656
StringTokenizer: 1745
split_tskuzzy2: 1887
string.split: 1980
split_banthar: 2421

This was my fastest attempt :(

    public static LinkedList<String> split_lucas(String s, char delimeter){
        LinkedList<String> elements = new LinkedList<>();
        int lastElementStartIndex = 0;

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == delimeter){
                elements.add(s.substring(lastElementStartIndex, i));
                lastElementStartIndex = i + 1;
            }
        }

        if (s.charAt(s.length() - 1) != delimeter){
            elements.add(s.substring(lastElementStartIndex));
        }

        return elements;
    }

At least the split_banthar (tested with copy/paste code) does NOT have the same behaviour has the JAVA SPLIT...