How can I access the previous/next element in an ArrayList?

Question

I iterate through an ArrayList this way:

for (T t : list){
  ...
}

When I did this, I never thought I had to access the previous and next eleme

Answer 1

As an answer to the title, rather than the question(with considerations to concurrent operations)...

T current;
T previous;
{
    ListIterator lit = list.listIterator(index);
    current = lit.hasNext()?lit.next():null;
    previous = lit.hasPrevious()?lit.previous():null;
}