Sorry for double posting. I'm just going to give a more in depth thing explanation of what I said before.
1. My program works fine now. In Orderlist i originally wrote
public class OrderList extends Vector<TreeData>
However using vectors doesn't show me using mastery. I need to have the code for the vectors and just change the variables and such. What I did was I took the source code of vectors and created a new class called "LinkedList".
So I replaced extends Vector<TreeData> with extends LinkedList and it doesn't work anymore. I changed the variables around but still. no can do :(
I hope that cleared things up abit. Thanks for your time.