Should I learn Spring 2 or 3?

Question

Spring Framework 3 seems to be right around the corner, but the GA version is 2.5.6.

If this is the first time I'm approaching the subject, should I start with the stable version, or should I start with the new version and save myself migration issues?

How different is version 3 from version 2? How near is Spring 3?

Answer 1

I would start with Spring 3 for various reasons:

• full Java 5 support (this is main reason for adopting Spring 3 for me)
• Spring MVC support is deeply change between spring 2 and 3 (notably REST support). Learning spring 2 MVC is not a far-seeing imho.
• new module organization (if you start with Spring 3, you don't need to migrate packages in the future)
• OSGI compabitiliy
• Ivy support

You don't need to worry about bugs or incomplete documentation since you are still learning the framework concepts. In conclusion, learning Spring 3 instead Spring 2 is a far-seeing choice.

However a very good introduction to Spring 2.x is given by Spring in Action, an excellent book about the subject.