Re: [JBoss-user] Question about CMP entity

[Marco T. <mt...@je...>]

Could you please forward some example?

Thanks,

Marco
----- Original Message ----- 
From: "Marco Garbelini" <ma...@ga...>
To: <jbo...@li...>
Sent: Wednesday, June 25, 2003 11:57 PM
Subject: Re: [JBoss-user] Question about CMP entity


The concurrency issue is not that simple. I never understood how the EJB
container deals with that completely. :-/

Anyway, I supose you are talking about PrimaryKey generation:

I use the Sequence Blocks strategy from Floyd Marinescu´s book EJB Design
Patterns.
It consists of a CMP(in my case) entity bean used just to persist the last
sequence used and a stateless session bean that caches blocks of sequences
(due to performance issues). I think its´s pretty nice.


Cheers,
Marco


----- Original Message -----
From: "Marco Tedone" <mt...@je...>
To: "JBoss-user-list" <jbo...@li...>
Sent: Wednesday, June 25, 2003 7:06 PM
Subject: [JBoss-user] Question about CMP entity


> Sorry guru for the [silly] question: I am having a discussion with people
in
> my project regarding the container work with CMP entity beans. More
> specifically, we want to implement a Numerator table to assign numbers to
> several entities of our model.
>
> Suppose a client wants to assign a value to a peopleId field in a People
> table, then it will in order:
>
> 1) Access the Numerator table (behind a CMP entity bean)
> 2) Retrieve the value from the number field;
> 3) Assign that value to peopleId
> 4) Increment the value by 1
>
> What I am saying to the guys in the project is that the container (Jboss
in
> our case) could ensure that, from the moment when the number is retrieved
to
> the moment when the number is  incremented by 1 nobody else will be able
to
> alter the value of the number field in the Numerator table. Someone is
> replying that we should implement a synchronized method. Is that really
> necessary? I'm quite sure that there is a way to instruct the container to
> 'lock' in a certain sense the value of the number field. One way could be
a
> transaction (shall we use synchronization in this case?); is there
anything
> simplier?
>
> Many thanks for your time,
>
> Marco
>
>
>
>
>
> -------------------------------------------------------
> This SF.Net email is sponsored by: INetU
> Attention Web Developers & Consultants: Become An INetU Hosting Partner.
> Refer Dedicated Servers. We Manage Them. You Get 10% Monthly Commission!
> INetU Dedicated Managed Hosting http://www.inetu.net/partner/index.php
> _______________________________________________
> JBoss-user mailing list
> JBo...@li...
> https://lists.sourceforge.net/lists/listinfo/jboss-user
>



-------------------------------------------------------
This SF.Net email is sponsored by: INetU
Attention Web Developers & Consultants: Become An INetU Hosting Partner.
Refer Dedicated Servers. We Manage Them. You Get 10% Monthly Commission!
INetU Dedicated Managed Hosting http://www.inetu.net/partner/index.php
_______________________________________________
JBoss-user mailing list
JBo...@li...
https://lists.sourceforge.net/lists/listinfo/jboss-user