Adding items to empty List at specific locations in java

Question

Is there any way I can make the below code work without commenting the 3rd line.

    List<Integer> list = new ArrayList<Integer>();
    list.add(0,0);
    //list.add(1,null);
    list.add(2,2);

I want to add items to list at specific locations. But if I don't change the index to Nth position I am not being able to add at Nth as told in this answer.

I can't use a map because I don't want to miss a value when the keys are same. Also adding null values to a list for large lists will be an overhead. When there is a collision I want the item to take the next position(nearest to where it should have been).

Is there any List implementation that shifts index before it tries to add the item?

Answer 1

Use something like a MultiMap if your only concern is not "missing a value" if the keys are the same.

I'm not sure how doing a shift/insert helps if I understand your problem statement--if the "key" is the index, inserting will lose the same information.