WHY EJB 3.0

[priyank yadav]

Why do we need EJB 3.0 when we have EJB 2.0.what are the Limitations encountered in EJB 2.0.
I fyou could let us know so that we can think of shifting our application from EJB 2.0 to 3.0.As i have heard its diffrent from EJB 2.0 altogether.

[Christophe Verré]

EJB2.X need lots of configuration, lots of interfaces. They also suffered because of Entity Beans. The persistence model is not cool.
The new version improves all of this, easing the pain of ejb developpers.
(I think that it doesn't make sense to explain in detail if you don't already know 2.X)

[Anthony Karta]

Hi,

If you don't find any limition in ejb 2.0, don't migrate it.

btw, check this link:
http://java.sun.com/javaee/overview/faq/javaee_faq.jsp#whymove

cheers

[Jeroen T Wenting]

Maybe a more pragmatic question would be whether it's possible to have an application that is a mix of 2.x and 3.x EJBs, and what the implications of this would be.

In other words, can I in an existing EJB 2.x application (once it's running in an application server that supports EJB 3.x) deploy EJB 3.x compliant EJBs or will they have to exist in an application of their own.

[Pradeep bhatt]

Mixing EJB 2.x with EJB 3.0 is possible as said by the author.

[Christophe Verré]

This would make migrating easier. No need to upgrade the existings beans. I wonder if we really can do that.

[Mike Keith]

In other words, can I in an existing EJB 2.x application (once it's running in an application server that supports EJB 3.x) deploy EJB 3.x compliant EJBs or will they have to exist in an application of their own.

You cn write 2.x beans and 3.0 beans in the same application. They would be in different EJB modules though.

This would make migrating easier. No need to upgrade the existings beans. I wonder if we really can do that.

I never lie.