What line is throwing the error? That is an enumeration error, and I am guessing that it is maybe this line:
check = tok.nextToken();
ummm..now I think I understand....look at the following line of code:
StringTokenizer tok = new StringTokenizer(this.getInput());
What is that line of code supposed to be doing? How can you check to see if it is doing what you think it is doing? What I am guessing is happening is that you are returning a null value, and when you hit the
it is throwing an error because there is no next token. I'm not sure though, because I can't get your code to run properly yet. :?