This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
I am reframing your question for the benefit of others:
You have an ArrayList of ItemInfo and that ArrayList can contain duplicate elements. So if the ArrayList has duplicate element- you add their ItemInfo.R value and then remove the duplicates.