For example : A list
A B C D E
Given C , Switch to
C A B D E
Notice that the array size will change, some items may removed in run times
Collections.swap(url, url.indexOf(itemToMove), 0);
What you want is a very expensive operation in an
ArrayList. It requires shifting every element between the beginning of the list and the location of
C down by one.
However, if you really want to do it:
int index = url.indexOf(itemToMove); url.removeAt(index); url.add(0, itemToMove);
If this is a frequent operation for you, and random access is rather less frequent, you might consider switching to another
List implementation such as
LinkedList. You should also consider whether a list is the right data structure at all if you're so concerned about the order of elements.