Changes in Spring for JDK 1.5 (Generics&Annotations)?

[mmc]

I am wondering what changes are planned for Spring to better support the new JDK 1.5 features (especially Generics and Annotation meta-data) ?

[Rod Johnson]

We're working on annotation support already (for transaction annotations etc).

Unfortunately backward compatibility is essential so we can't rewrite the framework internals using generics. Its surprising how many big enterprise users are still on 1.3, let alone 1.4, so we have 1.3 compatibility (although we use 1.4 optimizations). So although I would love never to have to pull another Object out of a Collection we can't think about that internally yet.

So what we do for 1.5 must be backward compatible, but we can autodetect and use more efficient classes etc in some cases.

We will probably do quite a bit on samples: for example, showing how if your project is using 1.5 you get to use generics and how that would impact the coding of an application using Spring.

[mmc]

Thanks for the reply! I understand and agree with the compability issues.

As you write new spring projects may benefit from using 1.5 features and examples of that would be very useful!

However since I am considering some using spring for new JDK1.5 projects that I want to be future-oriented, I am a bit concerned that some of the new JDK 1.5 features may soon cause the spring apprach to appear outdated and non-complient regarding meta-data. I.e. in a few years the idea of having all meta-data in XML files may be considered a legacy apprach because annotations would be the normal way to work with meta-data.

[hsteck]

However since I am considering some using spring for new JDK1.5 projects that I want to be future-oriented, I am a bit concerned that some of the new JDK 1.5 features may soon cause the spring apprach to appear outdated and non-complient regarding meta-data. I.e. in a few years the idea of having all meta-data in XML files may be considered a legacy apprach because annotations would be the normal way to work with meta-data.

I woundn't be so sure of that. It has already been discussed elsewhere, and though annotations are relatively new (compared to config files), both have their pros and cons, so I'd believe that both will coexist, perhaps forever. IMO, more "static" (compile-time) configurations will use annotation, and more "dynamic" (runtime) configurations will remain on XML files, maybe even allowing for XML config to replace annotations values. In this case, annotations could be seen as "default values", and XML files would be the way to redefine such defaults to different ones.

Regards,
Henrique Steckelberg