Java data structure

It is about singly-linked list of Strings in reverse order.

presenting two functions for reversing a singly-linked list

one is recursive

another is iterative

Both functions must be proven to actually reverse the list, and the nodes in the final reversed list should be the same ones as in the original list

(not just copies of the same content, but the same instanced objects).

Finally you should determine which one is better.(comparing two functions based on run-time efficiency and memoryspace efficiency)