Iterator has .next() - is there a way to get the previous element instead of the next one?

Question

I have an Iterator that I use on a HashMap, and I save and load the iterator. is there a way to get the previous key in the HashMap with Iterator? (java.util.Iterator)

Answer 1

It sounds like you want the array semantics more akin to a ListIterator rather than those provided by the Iterator interface. The easiest way to acquire such a thing is likely to construct a list ( from the key-set (LinkedList keyList = new LinkedList(map.keySet())), then use a ListIterator manually instead of a regular Iterator or foreach.

For very simple cases of needing to remember consecutive items, the simplest way to handle this is to store the previous Key in a local variable and update it at the end of the loop.