choose the right collection

[mickey0]

Hello,
I have:

Map<Var, Integer = new LinkedHashMap<Var, Integer>();
//with Var my own object

I need a collection that:
- no permits duplicates; that is fine
- keep the order of insertion //fine too
- I can retrive an element by its position //no fine!
- I can retrive the value by the key //fine

WHich is the best? I thought arrayList and every time check if the new element I want insert within, is not within yet. The problem is that I must to many extraction by position, for this reason I thought it wasn't the best. actually I thinking to store them by Integer key instead of Var since even the Intger give me the position. The problem is that in other part of the program I'm accessign to it by the Var key

suggestions? thanks