In this article, I will tell you about my experiences with Spring Roo. I will give recommendations when to use Spring Roo and when not to use it (yet).

What is Spring Roo?

“Spring Roo is a lightweight developer tool that makes it fast and easy to deliver instant results. Best of all, you code 100% in Java and get to reuse all your existing Java knowledge, skills and experience. You'll like it - and have plenty of fun too!” (http://www.springsource.org/roo)
Many introductory articles exist already, just use Google if you do not know Spring Roo yet. In a nutshell: Spring Roo is a Java-based tool (using the SpringSource Tool Suite which is based on Eclipse). It uses AspectJ to simulate many features of Grails and other frameworks with dynamic languages to improve the developer experience.

Spring Roo is awesome for CRUD-Clients!

You can create a CRUD application within minutes to create, read, update and delete data. I recommend Spring Roo for CRUD applications because of a good community and a powerful vendor (compared to other CRUD frameworks such as Roma Meta Framework or OpenXava).
Personally, I would prefer Grails, but if you want to create CRUD applications with Java, then Spring Roo is the best alternative.

Spring Roo is good for learning Technologies!

Spring Roo is also good for learning technologies because you get a working example in seconds, and you can create more complex stuff within minutes using the Roo Shell. Then you can learn and understand how Spring Roo uses these technologies.
Of course, Spring-based technologies such as Spring MVC or Spring Security are supported very well. Also JEE standards such as Bean Validation or JPA are supported. Besides, many further technologies are supported, e.g. GWT, JSF, Vaadin, Flex or Google App Engine. Actually, many of these addons are not production-ready yet - but Spring Roo is young and I am sure that many improvements will happen because of the large community.

Spring Roo is NOT good for complex Projects (yet)...

Please be aware, that this is my personal opinion due to my experience with Spring Roo: If you want to build something really complex, then you should use technologies such as JPA, GWT or Google App Engine without Spring Roo, because Spring Roo is not ready yet for this kind of project, and thus will probably create more questions than answers...
One exceptional case: If you want to realize an application which uses especially or better just Spring frameworks, then you might start your project with Spring Roo. It can be a huge help in the beginning of a project.

Conclusion: Spring Roo is a nice Tool => Become a Part of the Community!

My final conclusion: You should know Spring Roo, because it is nice, but you should also know when to use it and when to use something else. Use it to create CRUD applications or to learn technologies. Do not use it (yet) for complex, large projects.
Spring Roo is young and has a large community plus a powerful vendor. You should participate and become a part of the Roo community to make it better and production-ready (this does not mean you have to commit code – I do not commit code as well – but even if you only read the JIRA issues and vote for your favorites helps the community).
So, if you never used Spring Roo yet, try it out now!

Best regards,

Kai Wähner (Twitter: @KaiWaehner)

[Content from my Blog: When to use Spring Roo - Kai Wähner's IT-Blog]