How to remove items from an arraylist without shrinking the list
<p>I have a case where I am using the ArrayList to keep a list of items that are keyed by their position in the list.  Other objects reference the ArrayList items by their position.  If I delete one of the items from the list, I don't want the list to shrink because that would invalidate all other references to items in the list (e.g. item 2 is now in position 1).  My solution to the shrinking array list problem is to null the position in the arraylist so that the list will not shrink.  I am curious whether this will free the memory formerly held by the item at that position.</p>

<p>If there is a better way to accomplish this requirement, I would like to know about it.</p>
