As I wrote earlier, I got pretty excited about JRuby and especially about the idea of running Rails on top of it at RailsConf Europe. By pure coincidence we had just had started a project at webit! at this time which had to be deployed to the customer’s J2EE infrastructure. I didn’t really follow the JRuby development before, and therefore greatly underestimated its level of maturity. So, looking for a Rails-like way to build this application, I decided to go with the Groovy-based Grails framework.
At first Grails looks and feels much like Rails, however if you look closer and actually try to build a real application with it, the differences start showing up. Don’t get me wrong, when compared to the more traditional J2EE ways to build web applications (my experiences in this field range from plain Servlets to Struts and Spring), Grails is a huge step into into the right direction. Unfortunately for me, coming from Rails, it just didn’t feel right or complete in many places. Partly this is for sure because Grails, despite its name, is not just a Rails clone, but does things in its own way in many places. Without going into much more detail here, things often weren’t working the way I expected, and documentation was often outdated or missing.
Another issue with Grails for me was Hibernate, its persistence layer of choice. I simply can’t get used to the way Hibernate works. In my opinion it abstracts way too much from the database with its own query language and all its object oriented query building glory. Also it seemed to queue up sql statements and execute them at will at some later time, which I found irritating to say the least. I really don’t understand why Hibernate is the persistence framework of choice in so many J2EE projects. On the other hand it fits the ugly picture of the bloated J2EE web application quite well ;-)
To summarize this rant, don’t underestimate the learning curve of Grails, which will be even steeper when you aren’t already used to Hibernate. I think Rails people having to do J2EE development are just not the target audience of Grails. But it might be a good fit for J2EE developers who either already have their Hibernate models in place or at least have the will to invest some serious time in learning Hibernate.
After all, as you might already have guessed, I decided to start from scratch with JRuby and Rails after RailsConf Europe. And it really felt like coming home from a long and exhausting trip. Despite the lost time in the beginning we met our deadline and had a really great time solving problems the Rails way and deploying to JBoss every now and then. Right now I’m in the middle of my second JRuby on Rails project, same customer, same target platform. I plan to write some more articles about our experiences with JRuby, so stay tuned.