Moving from Resteasy Classic to Resteasy Reactive

[Pedro Igor]

Hi,

We started to prepare the initial set of changes in order to switch our JAX-RS implementation from Resteasy Classic to Resteacy Reactive.

The issue tracking this work is https://github.com/keycloak/keycloak/issues/10713.

This change is based on the following requirements:

* Make our JAX-RS code base more standard-based by removing references/usages of Resteasy API and internals

* Quarkus is pushing their community to Resteasy Reactive so that Resteasy Classic is no longer their focus. See https://quarkus.io/guides/resteasy.

The changes are happening incrementally and we have two main iterations:

* The first iteration is going to provide a fully working server using Resteasy Reactive and include the very basic changes to make it happen

* The second iteration is going to provide a completly review of our code that depends on Resteasy API and internals and make our code purely JAX-RS based. 

The changes comming with the #1 are basically refactorings to our JAX-RS resources and sub-resources in order to:

* Remove as much as possible the injection points in sub-resources so that we can create them as we do today without having to support context injection

Please, let me know if you have any comments and suggestions. We can discuss more in the issue I mentioned above.

Regards.

Pedro Igor