Somewhere around 2007 – 2008 I was setting up a new project which had a business model (BM) as the central component. The business model I envisioned had a three layered structure: an AbstractBean handling all the Java bean plumbing, a from-the-database-reverse-engineered class with the properties (setters and getters), and finally a class containing the custom code on top. I wanted to settle on a standard (JPA) and tried using Hibernate at first, but it could not support this layered structure back then, so I ended up using Eclipselink (and with great satisfaction ever since, I must add).
I also have never been a fan of pure application servers (EJBs), so this BM is compiled into a single jar (already postprocessed by Eclipselink), and simply included in all kinds of applications; a client-server Swing application, a REST interface to support an Android app, several im- and exporters for EDIFACT, emails, XML, and of course a nice in-house webapp. Not having an additional single point of failure (besides the database) is very pleasing and keeps the overall architecture much more simple. (more…)