Folks,



I read EJB entity bean specification. Looks like EJB entity bean can be called remotely with JNDI, which means Entity can be downloaded as a copy from different JVM. But seems Hibernate object can not do it.

am I right?



Thank you very much.



Chaohua

No, you are not right.

Could you tell me why?

or How to call a remote hibernate object?

or any link about this question?

Thanks a lot

Chwang,

we have to distinguish between different versions of the EJB specification here:

As of the EJB 3.0 release, Entity Beans are simple POJOs. They are not intended to be called remotely. Session Beans (both stateless and stateful ones) can be called remotely however IF they have a remote business interface.

By contrast, with earlier releases of the EJB spec (e.g EJB 2.0) Entity Beans supported remote calls via IIOP.

Wolles,

Thank you. According to what yuo said. Ejb3.0 or Hibernate object must bind with Session bean in the same JVM, so to Manipulate Database.

Am I right?

Chwang

Chwang,

I'm sorry, but I do not really understand your question. So it is difficult for me to give you an answer.

But back to your first post in this thread. There you wrote:




I think I can roughly guess what you meant. "can be called remotely" is probably the wrong wording here, creating confusion.

As I mentioned: As of EJB 3.0, Entity Beans are simple POJOs not intended to be called remotely from a different JVM. That means: They do not expose any methods intended to be called from another JVM.

But typically EJB 3.0 Entity Beans are serializable, which means that a copy of them can be passed as a parameter (function argument) of a remote method call from one JVM to another.

But note: When doing such remote calls from one JVM to another, it isn't a remote Entity which is called, but instead a method of the business interface of a remote Session bean (stateful or stateless). When doing such remote calls, Entity beans (and ordinary POJOs) can be passed as parameter (pass-by-value, so a copy of them gets passed from one JVM to another).

WolleS,

Thanks again. I see.

Sorry for incorrect words.

I still have 2 questions:

1.)


I created a UserAccount entity object for a UserAccount table in server site. the client will manipulate the object.

so at the client code should have a import package for the UserAccount?

like this:

import com.bean.UserAccount.

so the client code can pass compile, but client site must donwload the obejct first, otherwise how does the client refere the object. right?

2.)

right now, Can I say the EJB 3.0 is Hibernate ? because they are all POJO. or they have different functionality?