Regarding Session Beans!!

[Ravi Kumar Ravuru]

Hello Folks,
The difference between Stateless and Stateful Session Beans is,in the latter the state is maintained between method invocations by defining instance variables in the bean implementation class.If i define the instance variables in the stateless session beans...will the state be maintained?In the Stateful Session Beans,how do the container maintains the state.Please clarify my doubts?
Regards,
Ravi

[Lasse Koskela]

If i define the instance variables in the stateless session beans...will the state be maintained?

The most important thing is that you can't count on the state being maintained. It might, it might not. It depends on the EJB Container's implementation.
For example, in the following series of two method invocations to the same stateless session bean reference you can't rely on the two method calls being processed by the same bean instance (even though the reference is the same):
MySLSB slsb = home.create();
slsb.doSomething("This is the first call");
slsb.doSomething("This is the second call");

In the Stateful Session Beans,how do the container maintains the state.

Once again, depends on the EJB Container implementation. It might read the state from the bean using reflection and write it to disk, or it might serialize the whole bean instance to disk.