I am currently leading the charge for our clients with Java-based web applications to adopt Grails (i.e. Groovy on Rails). Grails (www.grails.org) has recently achieved its official 1.0 release, just behind the 1.5 release of Groovy. We’re seeing a 10-fold increase in productivity by using GSP (Groovy Server Pages) over JSP (Java Server Pages), and that factor is only going to improve with practice, and as Grails moves beyond 1.0.

The biggest hurdles we’ve have to overcome with Grails have all had to do with writing Grails apps against an existing database schema. Anyone starting completely from scratch, allowing Grails to define the schema, won’t have any trouble at all. For anyone who is about to go through what we did with a legacy schema, I’ll be writing up my notes shortly. Look for them to be posted on our companion blog, www.codejacked.com.

Getting started with Grails requires two efforts: learning how Groovy extends Java, generally, and learning how Grails then takes advantage of Groovy for rapidly developing web pages. For the former, I highly recommend the brand new book, Groovy Recipes by Scott Davis (Pragmatic Bookshelf). Chapter three exactly and concisely explains what an experienced Java programmer needs to know to get started with Groovy.

After that, The Definitive Guide to Grails by Graeme Keith Rocher is probably where you’ll turn. Be aware, though, that a second edition is pending, and you’ll want to update your copy when it comes out, so budget accordingly.