Marco Ehrentreich wrote:I don't have much practical experience with OSGi/Spring myself but from what I know, it may depend largely on what exactly you mean with "Spring". Spring itself consists of many more sub-frameworks. So the time for studying may vary a lot.
Right. At the core of Spring is dependency injection (DI). And DI is a fairly simple concept. If you know how to write setter methods, then you already know the hardest part.
Sure, the whole Spring portfolio builds on top of that, but there's no need for you to learn EVERYTHING
about Spring. Start with DI, then branch out to AOP...then I'd suggest trying out the persistence support (for JDBC
and ORM frameworks). Then give Spring @MVC a spin. But you don't have to follow my advice...just learn a little at a time. That's the nice thing about Spring is that it offers a lot of stuff, but you don't have to learn all of it to benefit from any of it.
OSGi is kinda the same way. There's a lot of compendium stuff associated with OSGi, but the core is fairly straightforward. You can have your very first OSGi bundle up and running in less than an hour (including time to download an OSGi framework)...from there you can decide an exploration path that suits you best.