In Relation To

Now that the EJB 3.0 early draft is out there, it's definitely time to move on from all the recent politics, and start thinking about what we can actually /do/ with this stuff. EJB is the only Java standard which addresses server-side /business logic/, and is thus central to J2EE. The EJB spec committee recognizes that EJB has fallen short of achieving some of its ambitious goals, and is in need of an overhaul. This overhaul has focused very much upon ease of use, primarily via simplification of the requirements upon bean implementors. However, the spec committe also identified a number of critical functional enhancements that facilitate ease of use and the elimination of certain J2EE anti-patterns.

Another blogger, who will remain unmentionable, is upset that some of the guys at JBoss are beginning to throw the term AO around. According to him, the AOP community is just terribly attached to their P, and quite concerned that JBoss might be about to dominate the world with their P-less aspects.

I've posted the slides for two recent presentations.

Recently, we've started to hear complaints that we don't put enough effort into free support in the Hibernate forums. This really kinda hurts, since everyone /used/ to comment that we gave such /great/ support, and since I still spend hours most days reading and responding to forum posts. I don't get paid for this, and I rarely get thanked for it either (even by the people I do get time to respond to). I've been doing this for almost three years now.

Hibernate is great at representing strongly-typed, static object models. Not all applications are like this. Metadata-driven applications define entity type information in the database. Both the object model and the relational model support dynamic addition of new types, and perhaps even redefinition of existing types. Actually, most complex applications contain a mix of both static models and dynamic models.

This is /just great/ ...

We've seen a few people using internationalized reference data where labels displayed in the user interface depend upon the user's language. It's not immediately obvious how to deal with this in Hibernate, and I've been meaning to write up my preferred solution for a while now.

Abe White of Solarmetric replies to my criticisms of JDO on TSS. I'm actually not interested in getting into a lengthy debate over this, but since there /was/ an error in my first post, I must certainly acknowledge that.

Yesterday, Linda DeMichiel announced the changes coming in EJB 3.0. There was a lot to digest in her presentation, and I think it will take a while for people to figure out the full implications of the new spec. So far, most attention has focused upon the redesign of entity beans, but that is most certainly not all that is new! The expert group has embraced annotations aggressively, finally eliminating deployment descriptor XML hell. Taking a leaf from Avalon, Pico, Spring, Hivemind, etc, EJB will use dependency injection as an alternative to JNDI lookups. Session beans will be POJOs, with a business interface, home objects have been eliminated. Along with various other changes, this means that EJB 3.0 will be a much more appropriate solution for web-based applications with servlets and business logic colocated in the same process (which is by far the most sane deployment topology for most - but not all - applications), without losing the ability to handle more complex distributed physical architectures.

Like, I suppose, many Java developers, I have so often read about the supposed scalability problems associated with stateful session beans, that I simply accepted that these problems were real, and refused to even consider using stateful beans. I guess this was laziness, but we don't have time to verify everything we read - and I'd never had cause to doubt that what I read was correct.