John,
The FoodSmart example application in our Developer's Guide wraps regular 'ol
domain objects with Entity Beans. In fact we can use Entity Beans or not
through some policy layers. This is all open source and available upon
request from our WEB site.
Regards,
-Chris.
> -----Original Message-----
> From: john smith [SMTP:[EMAIL PROTECTED]]
> Sent: Tuesday, March 14, 2000 10:51 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Design question: entity beans, wrapping domain objects
> and su ch...
>
> Thanks for your response!
>
> I understand you want to wrap entity bean access in session beans, and I
> thought I stated we were doing that, I am interested in hearing from
> people
> who are going a step further and wrapping Domain Objects in entity beans.
>
> Here's what I am talking about:
> Client --> SessionBean --> EntityBean --> DomainObject
>
> The entity bean is a wrapper around the domain object, so my question was
> about accessing, using and updating the Domain Object from the session
> bean.
> How are people doing this?
>
> Thanks!
>
>
>
> >From: [EMAIL PROTECTED]
> >Reply-To: A mailing list for Enterprise JavaBeans development
> ><[EMAIL PROTECTED]>
> >To: [EMAIL PROTECTED]
> >Subject: Re: Design question: entity beans, wrapping domain
> >objects and su ch...
> >Date: Tue, 14 Mar 2000 10:12:44 +0100
> >
> >We use entity beans to model our Domain Object Model. But the clients
> never
> >use those entity beans. Instead the clients use Session beans, which
> >internally use those entity beans. The session beans interfaces are
> modeled
> >to provide some sort of low-level-use-cases to the client. All
> information
> >the client needs is provided thru session beans. This information is
> either
> >wrapped in serializeable objects or in XML, so the client can work
> locally
> >on the data and send it back (thru a session bean) to the server
> >
> >Mit freundlichen Gr��en
> >With kind regards
> >
> > > Ulf Gohde
> > >
> >System Architect
> > > CE Computer Equipment AG Fon: +49 (0)521 9318-167
> > > Herforder Str. 155a Fax: +49 (0)521 9318-444
> > > 33609 Bielefeld mailto:[EMAIL PROTECTED]
> > > Germany http://www.ce-ag.com
> > >
> > >
> >
> >
> >-----Original Message-----
> >From: john smith [mailto:[EMAIL PROTECTED]]
> >Sent: Friday, March 10, 2000 9:37 PM
> >To: [EMAIL PROTECTED]
> >Subject: Design question: entity beans, wrapping domain objects and
> >such...
> >
> >
> >We want to take advantage of entity beans and CMP, but also want to
> >preserve
> >our Domain Object Model to the greatest degree possible. It is sometimes
> >suggested that an entity bean simply wraps the java object. The entity
> bean
> >would then have two attributes of interest to us, the id, and a reference
> >to
> >the java object it represents.
> >
> >Thus we never really act on the entity bean, instead we get the domain
> >object from it, act upon it and give it back to the entity bean to
> persist.
> >
> >We may also do "large" queries using sql in session beans, construct our
> >domain objects from the results, and when done, pass them back to an
> entity
> >bean for transactional updates.
> >
> >I would like to expose only the domain objects to the clients (session
> >beans) probably using a facade of some sort with which our "findBy"
> >requests
> >would be delegated to the actual entity bean and the facade would return
> >back to the client, domain objects.
> >
> >
> >Questions:
> >
> >First - I'd like to know if anyone is using domain objects wrapped by
> >entity
> >beans, and if so, can you provide some insight into how you actually use
> >the
> >domain object from a client. Thoughts?
> >
> >
> >Heres the first thing I come up with:
> >Lets say we want to use a simple mutator on a domain object, for example,
> >change a patients telephone number.
> >
> >1 - the client makes a request for patient with last name of smith.
> >
> >2 - If we were directly accessing entity beans from the client (session
> >bean) we would have 3 remote references, update the one of interest and
> the
> >container would insure it was persisted...
> >
> >In our case we get back three domain objects. We update the one of
> >interest,
> >and then what??? Sure, we submit it back for persistence. The facade will
> >use the id to look up the entitybean, update it and persist it. But this
> >seems like a lot of work!
> >
> >Any other ideas?
> >
> >THANKS!!!
> >______________________________________________________
> >Get Your Private, Free Email at http://www.hotmail.com
> >
> >=========================================================================
> ==
> >To unsubscribe, send email to [EMAIL PROTECTED] and include in the
> body
> >of the message "signoff EJB-INTEREST". For general help, send email to
> >[EMAIL PROTECTED] and include in the body of the message "help".
> >
> >=========================================================================
> ==
> >To unsubscribe, send email to [EMAIL PROTECTED] and include in the
> body
> >of the message "signoff EJB-INTEREST". For general help, send email to
> >[EMAIL PROTECTED] and include in the body of the message "help".
> >
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
>
> ==========================================================================
> =
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
> body
> of the message "signoff EJB-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
