Posts Tagged ioc

I’ve just finished getting up to speed with Google’s Guice 2.0 and have integrated it into two of my projects. It’s been a very comfortable experience and I could see myself Guicifying most of my Java projects from now on.

To summarise my experiences – Guice is a Dependancy Injection and Aspect Oriented Programming framework for Java. This is the turf that’s normally owned by Spring of course.

So how is Guice different to Spring?

• No XML!
• Narrower scope: Guice only does DI and AOP, unlike Spring which covers a wide gamut of requirements.
• Heavy and mandatory use of annotations.
• …and in my opinion, a more refined and elegant design.

I think one of the main reasons I like Guice so much is the absence of XML. I really hate XML and Guice’s “Module” concept is a great replacement for text configuration. I would be interested to know how often in practice that Spring’s XML configuration is changed in situations where a rebuild of the application is impossible. The argument for that sort of configuration has always seemed like a straw man to me. As a bonus of the Guice Module approach, you get type checking and compilation of your configuration. [It would be interesting to see if someone does implement an XML configurator for Guice though - I'd say it's only a matter of time].

How to get up to speed real fast?

1. If you’re not familiar with DI and/or AOP then do some reading. A framework can only solve a problem that you know you have.
2. Watch the recent Google IO tech session for the 60 minute fast-track introduction.
3. The Guice wiki is helpful, but I found the external links and discussion group to be more helpful.
4. Write something! It’s a dead easy framework to get your head around, and the fastest way to solidify your knowledge is to do.