Data logic & Business logic
if ur application is heavy on data logic than the business logic in the sense that it handles huge data. But at the same time, it doesn’t involve complex business logics & doesn’t represent a complicated transaction system, it is better to go for servlets itself.
Network call with EJB
Internally, J2EE uses the
Java Remote Method Invocation over Internet Inter-ORB Protocol (RMI-IIOP) to enable remote, distributed method calls and applications. While this approach provides benefits, it also generates a large amount of overhead, with a corresponding performance hit as stubs are referenced, parameters go through the marshaling process, and objects are tossed around the network.
Implementing middle tier services
EJB has a middle tier, which implements services such as instance pooling, transactions, security etc. The required services can be implemented in the non-EJB environment and tailored to the needs of our application with the required changes in the settings & the code without going for EJB.
Example:
Proper handling of objects, which makes Garbage Collection efficiently happening through out, user transaction etc.
EJBs are costly in terms of development.
We require having a set of deployment descriptors and Home & Remote interfaces. We require taking care of setting the right TX attribute for the business methods. And also, Deployment & maintenance will be costly in terms of time and resources.
In the case of java components, we don’t require to do what ever mentioned above.
But, when we have IDEs like WSAD, this point is not fully valid as these IDEs facilitate many things that we require to do.
Resource pooling without EJBs
Almost all major J2EE servers allow us to get connection pooling and
thread pooling whether we use java components or EJB components.
