My Review on Spring-Roo

So I gave a presentation about Spring Roo recently. Hopefully this means I'll get a kangaroo.  I felt it went pretty well. I decided to share some of my remarks as I think I learned more by presenting than by trying it. As I can not put a presentation on my document (yet), I'll show the text of my slides and will explain some of the things I discussed while presenting.


Describing Roo

• Rapid Prototype tool for the Java Platform.
• Non-Invasive approach to development.
• Proper use of open source frameworks.
• Handles Infrastructure configuration
• Intelligent Code Generator (Active vs. Passive Generators)

I basically defined Roo as a tool that can help you learn (if you are new), refresh (if you are Spring savvy), or simply complement your current skills.  Although Spring has made a tremendous job in keeping us away from traditional J2EE development (EJB, xDoclet, Ant, etc), managing Spring configuration is extremely easy with Roo. No need to understand a complete Transaction Strategy in the beginning. No need to understand how to setup i18n configuration, nor how to setup a JPA provider. I also took time to explain about Roo's powerful shell and how it synchronizes with changes you can make with the IDE (managed asset).

Installing Roo

• JDK 5.0 or greater
• Maven 2.0.9 or greater
• Spring Roo Binaries

In this slide (very short) I essentially emphasized how wonderful I managed to work with Roo at home in a machine where I didn't have admin privileges. This opened some eyes as I sensed some of my audience had the same problem. Furthermore, the idea of the shell was very compelling to some folks. Also, I noticed that hitting the "Tab" for hints was a nice feature to have. I could immediately tell most of the folks in attendance would prefer command prompt whenever possible.

Roo Concepts

• Under the covers, Roo uses AspectJ and Java
• Changes are done at the byte-code level
• Strong use of Inter-Type Declarations (ITD)
• Leverage the power of Privileged Aspects
• Annotations are defined with Source-Only Retention Policy

I felt that this is where I spent most of my time (aside from the Demo I gave). I explained the concept of ITD as it was fairly new to some of the audience. Also, I had to explained a bit about Privileged Aspects. I had sensed (from the previous presenter) that the audience was not well versed in AspectJ (nor AOP), so I took my time here to help the audience understand that a "cross-cutting" concern does not necessarily apply to business logic. It was a good discussion. After answering some of the questions I had, I turned to build an application which some of us have been talking about building, of course this time it was a lot faster. 

Value Proposition

• No vendor Lock-In
• Zero performance/memory overhead
• Zero deployment footprint
• Consistent applications across teams
• Leverages investment in the Java Ecosystem
• Small learning curve, great to learn proper usage of Spring.

I felt I needed to present why is the "Roo" proposition a good one. As a convert to Roo, I liked the lack of vendor lock-in. I also appreciate the great "use-case" for AspectJ in the context of this tool. It makes complete sense. I also stressed the point of how to help "entry" level Engineers to learn powerful concepts which could take days to read on their own.

Further Topics

• Dynamic Finders
• Integration with JMS and Email
• Integration with Webflow
• Integration with Spring Security
• Custom Add-on's
• Roo Architecture Patterns

As my presentation took longer than anticipated, I didn't have the chance to discuss these, however I had purposely left it in case I would have finished early. I suggested a future discussion of this topics, particularly about "Dynamic Finders" and some of the architectural choices which Roo encourages (e.g. No DAOs, Optional Service Layers, etc).

I sensed good feedback, and once again I learned the obvious: One learns more by sharing than by reading.