Creating an ArrayList from an existing LinkedList si done using the following constructor.
ArrayList(Collection c)
Constructs a list containing the elements of the specified collection,
in the order they are returned by the collection's iterator.
Following is an example:
LinkedList ll = new LinkedList();
ll.add("ll1");
ll.addFirst("ll2");
ll.addLast("ll3");
ArrayList arrayList= new ArrayList(ll);