The second session i attended today at Javapolis was a session by Mike Keith of Oracle. Mike is a co-spec lead for the EJB 3.0 specification, and he has a lot of persistence experience. He also works on Oracle’s Toplink project.
I shortly talked to Mike before his presentation, and asked the question most people using Oracle’s ORM frameworks ask. What’s it going to be, ADF Business Components or Toplink? This is an interesting question, especially now that Toplink is part of the EJB 3.0 Reference Implementation. What is Oracle using for its own projects? According to Mike both ADF-BC and Toplink are being used for new projects, but most projects seem to prefer Toplink. He expects most people to move to EJB 3 once it’s released and stable.
Mike started his presenation with a slide called “About You”, which i liked. It showed that he really had thought about who his audience was, and what they wanted to get out of the presenation. It’s a bit surprising, but too many presenters forget to do this. Maybe it would be a good idea to send all presenters a copy of “Beyond Bullet Points“. Knowing your audience is one of the main points of this book. (Another one is to get rid of all the bullet pointed text on your slides. I think this works really well, even for technical presentations. Just show code and diagrams.)
Anyway, back to the subject, EJB 3.0 persistence. A new reference implementation will available by New Year 2006, and the final release is expected for JavaOne 2006. The reference implementation uses Suns Application server, Glassfish, and Oracle ORM framework, Toplink essentials. Toplink essentials is a stripped down version of Toplink, without some extras like the Oracle DB specific extensions, object xml mapping, etc.
Mike explained the goals of EJB 3, simplicity, what an entity is, how to use annotations and xml, to define mapping and ids. Also discussed where the Persistence Context, Entity Manager, Entity lifecycle. The entity manager API contains methods to persist, refresh, remove and query objects. Using callbacks you can add business logic before and after updates, inserts, and deletes. Again, these callbacks can be specified using annotations. He finished the session with some examples of queries, named queries, native queries and relationship mapping.
I liked Mike’s presention, he gave a good introduction into EJB 3.0. I also think EJB 3 has a good change of becoming the standard ORM framework (not just on paper), since you can also use it in JSE application without a JEE container. It’s also a lot simpler that previous EJB versions.
December 14th, 2005 at 14:49:08
Surely some Oracle Consulting projects use Oracle Toplink and some of them use ADF Business Components. I don’t know what the breakdown is percentage-wise. In the large we find, as might be expected, that experienced J2EE developers prefer the flexibility of Oracle Toplink while developers coming from a Forms/4GL tools background prefer our ADF Business Components. This is definitely how we position the technologies in our Oracle Developers Days seminars. Over 4000+ developers inside Oracle Applications use today and will continue to use ADF Business Components. The unified Oracle Applications teams (after the Peoplesoft merger) will continue to use ADF Business Components as well in the future. There are over 2000+ external customers and partners using ADF Business Components today, too. We anticipate to be able to evolve ADF Entity Objects to leverage EJB 3.0 persistence in the future once the EJB 3.0 spec has stabilized.
December 14th, 2005 at 23:26:24
Hi Steve,
Thanks for your comment. Good to know that Business Components are still heavily used and will be used in the future. We are also using Business Components and we’re happy with the framework. I agree with your statement that it’s easier to use for people with a Forms developer background. But that’s only as long as they can drag and drop and use properties. As soon as some requirement pops up that requires them to start coding java, big question marks appear. (Btw, the same goes for adf bindings, nice as long as you can drag and drop and use properties, but once you need to start coding, it doesn’t make you more productive) Not much difference between business components and other ORM frameworks.
But having seen some presenations on EJB 3, i believe that EJB 3 will become popular, also at the cost of business components. People like to stick to standards, and ejb 3 is a standard, bc4j is not. (maybe it has a change if you guys open source it?) Ejb 3 resembles popular OMR frameworks like Toplink and Hibernate, so it will also be easy for people who current don’t like ejbs but would prefer to use some standard. It will be hard to sell a non standard ORM framework when a good standard is available.