STOP posting snippets. Use the Reply button and the Additional Options link that appears below the text field, and attach your code AS ONE FILE.
There is NOTHING in the code that NEEDS to use Strings. You have embedded all the dependencies on the String class. You can get rid of them, but it is NOT going to be a matter of waving a magic wand and making them go away.
You have some undefined splitString() method that populates an array of Strings. It could just as easily populate an array of strings.