You may have already heard JAX-RS 2.0 (JSR-339) has been released. This is a very good news for Java developers building their RESTful HTTP applications and here are the reasons why.
The 2.0 API offers a lot of new enhancements on top of already very capable JAX-RS 1.1 (JSR-311) API and spec. It has really been a very serious push to the next level across all the API and the specification text. And what is really good is that the community can now rest assured: the JAX-RS effort started by Paul Sandoz and Marc Hadley is very alive and is led by a new super team, Marek Potociar and Santiago Pericas-Geertsen who worked extremely hard to get JAX-RS 2.0 out.
As I said the new API offers a lot of enhancements: client and server filters and interceptors, new Client API, client and server asynchronous invocation support, a lot of new context classes, new exception classes, a lot of API updates. A lot of new things to try and learn, but what I personally like most is the new asynchronous API and the fact that JAX-RS 1.1 Response class can be reused by Client API - it seems like a minor thing but IMHO it's one of the major points.
I've enjoyed taking part in the JAX-RS 2.0 development process. Talking to all the participants, 'fighting to death' on the subject of very trivial issues, running never ending threads - it has all happened and it has been great :-). As every developer out there knows sometimes one has to forget about the disappointment of having your great point of view rejected :-), and move on with the team toward making something good happen - this is what this spec effort has been about.
Talking to one of my former team leads, Bill, has been super too :-). As a side note, a lot of API enhancements have their origin in the work Bill and his team did.
JAX-RS 2.0 is out and about to take over and fly high. It is only a start, MVC support, some new useful features will hopefully and likely be in in the next major releases. Is it perfect ? Probably not - I can name few API and spec features I'm still not feeling exactly happy about, but overall JAX-RS 2.0 is great.
In Apache CXF we are going to have JAX-RS 2.0 completely implemented by the end of the year. As it happens 2.0 server-side API is already completely implemented on the trunk. Some of the features like the integration with Bean Valdation API is required by the EE profile only but I think we can wire that into CXF too.
It is also validated against the early TCK 2.0 build (with Andrei helping a lot).
Client API is 50% done - CXF WebClient API has been enhanced to support new Client interceptors and filters, Response and even Asynchronous Invocations (with thanks to Dan). Still some work to do on the actual new Client API. We are getting there.
So try JAX-RS 2.0 API and enjoy !