A stock company has operations in all major exchanges worldwide. Stockbrokers spend 80
percent of their trading time logged into and using the company’s main application –
BuyLowSellHigh. It is redesigning BuyLowSellHigh to use the Java EE platform. Key requirements
are to minimize the size of messages sent between application tiers, and provide a consistent
state mechanism for both Java Swing and HTML-based application clients. Server-side resources
are dedicated to users for the lifetime of their session and the company charges a premium to its
traders to ensure that resources do not need to be pooled or reused. Given these requirements,
what is the best approach to maintaining state in the business logic tier?
A.
The HttpSession object accessed from the HttpServletRequest object
B.
A handcrafted singleton class accessed by the presentation tier using RMI-IIOP
C.
An entity bean acquiring and releasing resources as needed to service requests
D.
A stateful session bean created and associated with the client on login until logout, acquiring
and holding all server-side resources needed