Interview Question: Is it possible to share an HttpSession between a JSP and EJB? What happens when I change a value in the HttpSession from inside an EJB?

By: Ash Printer Friendly Format    

Question:Is it possible to share an HttpSession between a JSP and EJB? What happens when I change a value in the HttpSession from inside an EJB?

Answer:

You can pass the HttpSession as parameter to an EJB method, only if all objects in session are serializable.This has to be consider as passed-by-value, that means that it’s read-only in the EJB. If anything is altered from inside the EJB, it won’t be reflected back to the HttpSession of the Servlet Container.The pass-by-reference can be used between EJBs Remote Interfaces, as they are remote references.

While it is possible to pass an HttpSession as a parameter to an EJB object, it is considered to be bad practice in terms of object-oriented design. This is because you are creating an unnecessary coupling between back-end objects (EJBs) and front-end objects (HttpSession). Create a higher-level of abstraction for your EJBs API. Rather than passing the whole, fat, HttpSession (which carries with it a bunch of http semantics), create a class that acts as a value object (or structure) that holds all the data you need to pass back and forth between front-end/back-end.

Consider the case where your EJB needs to support a non HTTP-based client. This higher level of abstraction will be flexible enough to support it.

 

 

 

 



Most Viewed Articles (in Interview )

Interview Question: What about JSTL and JavaServer Faces ?

Interview Question: Is there a particularly good IDE to use with Struts ?

Interview Question: Do ActionForms have to be true JavaBeans?

Interview Question: What is Remote client view?

Interview Question: What are the optional clauses in EJB QL?

Interview Question: What is the difference between EAR, JAR and WAR file?

Interview Question: What is re-entrant. Is session beans reentrant. Is entity beans reentrant?

Interview Question: How many EJB Objects are created for a Bean?

Interview Question: What is deployment descriptor?

Interview Question: What are the call back methods in Entity bean?

Interview Question: What is Message Driven Bean?

Interview Question: What is local interface. How values will be passed?

Interview Question: What is abstract schema?

Interview Question: What is the difference between find and select methods in EJB?

Getting started with Interview

Latest Articles (in Interview)

Comment on this tutorial