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.
The instances in the pool are "flyweights" and abstract factory pattern is used for creating object refernces since the ejbobject implementation class is unknown to the client. For ejbobject implementation both inheritance and delegation is used as mentioned on page37. please correct me if Iam wrong