we are definitely using OJB hardcore in a J2EE environment. We use the Stateless session bean with value objects approach. Over 350+ different classes mapped. Every type of relationship. Non trivial.
I'm not sure how much this will help you, but fwiw. m -----Original Message----- From: Thomas Mahler [mailto:[EMAIL PROTECTED]] Sent: Thursday, September 26, 2002 10:10 AM To: OJB Users List Subject: Re: OJB/JDO in a EJB context Hi, [EMAIL PROTECTED] wrote: > Microsoft has not the "Hype marketing" monopol !-) > In my opinion, Sun doesn't provide nice position on JDO vs Entity beans. > Do you expect SUN to admit that entity beans are an obsolete concept? > Christophe > > -----Original Message----- > From: Thimo K�nig [mailto:[EMAIL PROTECTED]] > Sent: jeudi 26 septembre 2002 15:59 > To: LOMBART Christophe (BUDG) > Subject: AW: OJB/JDO in a EJB context > > > Hi Christoph, > > > >>I'm just wondering what is the best design pattern to used >>OBJ in a ejb environement. I'm really interesting to receive >>your feedback about different experiences in this area. > > > I am asking myself the same questions since several days. I didn't get > propositions which satisfied me. Seems nobody uses seriously OJB in a > J2EE environement ;-( maybe everyone is busy implementing and has no time to answer... > >>The first solution can be : session bean wich is using >>direclty OBJ as a persistence manager. Entity beans are >>completly ignored in this case. Is it make sense for you ? > > I generally recommend this approach! > We already thought about this pattern too. Another problem is that there > a no remotecalls posible to the entities. So every client needs to have > his own "copy" of ValueObjects to present Trees etc. We got large Trees > an don't want do send them completely to each Client... > 1. OJB proxies are portable. That is you don't have to send large object nets, but can use OJB proxies to provide lazy materialiation for session bean clients. 2. you can manage loading of object references within your session beans. That is, if you set auto-retrieve="false" so references and collections are simply set to null. If the client must access such a reference the session bean can use explicit PersistenceBroker calls to load the respective reference and send it to the client. > > >>The second solution can be : BMP based on OJB like samples >>provide with OBJ. What about the entity bean granularity ? >>How to define relationship between business component (on the >>entity level or OBJ level) ? > > > Anyway Container Managed Relations depends on C-M Persistence, so we > should handle all relations by ourselfs... > > Other question why do I have to access OJB via the ODMG API? The > proprietery query interface is much nicer... you can use the PersistenceBroker queries with ODMG apps. see the FAQ for details. > As you see I don't know much more than you do. I'm kind of disappointed > because even after reading a lot of Postings, Mails, J2EE Design > Patterns etc. I didn't find a good and simple approach or suggestion. > there is no such thing as a free lunch... cheers, Thomas > Regards > Thimo > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
