This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
If you get that exception with (5) it means you are trying to access the No 5 (i.e. 6th) member of a 5‑element, or smaller, array. That array might be hidden inside an ArrayList or similar class. Use the stack trace to work out whereabouts in the code it happened.