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EJB 3.0 puzzle...

Sudarshan Sreenivasan
Ranch Hand

Joined: Jun 28, 2007
Posts: 188

Hi,
I have read a bit about ejb 2.0 and now i reading about ejb 3.0 .. I am very curious as to how the whole concept of home interfaces has been eliminated especially when they seemed to be so crucial in the earlier version !!!

They made the beans after all

So i just wanted to know what new mechanism sun has adopted to avoid them & if it was so obvious (Not explained anywhere as to how they have been eliminated) why where home interfaces there in the first place ???

Is there any book or website that teaches ejb 3.0 atleast the session bean part comparing them with ejb 2.0 the motivations and techniques used to overcome the limitations of ejb 2.0 !!!


Thanks !!
Shahnawaz Shakil
Ranch Hand

Joined: Aug 04, 2008
Posts: 57
First you should understand the perpose of home and object interface in previous versions.Home interface served as a factory for creating references in the EJB object. Similarly the main purpose of the EJB object interface was to provide the client view of an EJB, meaning that the EJB object carried all the business methods that the bean wanted to expose to its local or remote clients. This clue will help you to understand how things have changed now.
Sudarshan Sreenivasan
Ranch Hand

Joined: Jun 28, 2007
Posts: 188

Hi,
From what i gather & after a bit of reading is that the home interface would have roughly the same code for all types of beans so this job could be handled by the container.

The remote interface has sort of been substituted by the business interface.

Just give me a few more hints probably i will get a better understanding.

Thanks
Chaminda Amarasinghe
Ranch Hand

Joined: May 17, 2006
Posts: 402
Hi sid sree,

Read 1st (or 2nd) Chapter of Mastering EJB 3 (Ifs free to download) , That describes the thing clearly.

Thanks
Sudarshan Sreenivasan
Ranch Hand

Joined: Jun 28, 2007
Posts: 188

Hi,
I did go through that... and only according to that understanding did i post my previous reply.

However the question still remains is that if it was this evident then probably the sun guys should have catered it in ejb 2.0 itself ?

I have a feeling that ejb 3.0 has painted a over simplified version of it & therefore i am just curious
Sergio Tridente
Ranch Hand

Joined: Mar 22, 2007
Posts: 329

Originally posted by sid sree:
However the question still remains is that if it was this evident then probably the sun guys should have catered it in ejb 2.0 itself ?


EJB 3.0 makes an extensive use of annotations in order to achieve the so much desired simplification. Remember that annotation were introduced in the Java language with version 5.0.


SCJP 1.4 (88%) - SCJP 5.0 Upgrade (93%) - SCWCD 1.4 (97%) - SCBCD 5.0 (98%)
 
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subject: EJB 3.0 puzzle...
 
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