– Thomas Paine, Common Sense (1776)

Coincidentally, InfoQ addressed this same question just a couple of days later, and it appears that a small portion of the JEE blogosphere has debating the issue for some time now. The consensus, which I agree with, is that it really depends on the application. If you have a relatively small domain model, it might be a good idea to forgo custom DAOs.

I’ve been experimenting with this approach in a small application which I’ve been developing as a pet project, and I’ve been very pleased thus far. The only aspect which makes me slightly uncomfortable is the sprinkling of JPAQL which now exists in my service layer. A criteria API similar to the one offered by Hibernate would, in many cases, be a good alternative to JPAQL, and I seem to remember having read somewhere that JPA 2 will include this feature.

So is it time to say goodbye to DAOs? Not at all. Anyone developing an application with more than a dozen domain objects should think long and hard before throwing time-honored best practices overboard.

But there’s a gray area somewhere in the spectrum between “homebrew CD collection tracker application” and “commodity market trading backbone.” As your domain model gets smaller and smaller, your DAOs will start to look more and more anemic, and it’s possible that at a certain point you may say “forget it, I’m going DAOless.” Just know that you’re not alone.