MP Rest Client should use CDI AnnotatedType information to find interceptor binding annotations rather than reflection

[Azquelt]

Currently, MP Rest Client looks for interceptor bindings on the rest client interface using reflection in order to call interceptors annotated with @AroundInvoke when methods on the rest client bean are called.

However, CDI is required to use it's AnnotatedType information to find interceptor bindings, not reflection (so that CDI Extensions have an opportunity to add or modify them).

The container must use the operations of Annotated and its subinterfaces to discover program element types and annotations. The container must not directly call the Java Reflection API. In particular, the container must:

• call Annotated.getAnnotations() to determine the scope, qualifiers, stereotypes and interceptor bindings of a bean,

CDI 11.4

MP Rest Client should do the same so that interceptor bindings work consistently between rest client beans and other CDI beans.

This is the cause of the additional code we currently have in MP Rest Client to handle Fault Tolerance interceptors.

[Azquelt]

I think this is what we need to do:

In the CDI extension, have a @Observes @WithAnnotations(RegisterRestClient.class) ProcessAnnotatedType<?> method which will be called for each class annotated with RegiterRestClient. Build a collection of all of the rest client interfaces. Do not veto the type (it's an interface, so it shouldn't be treated as a bean by CDI anyway, and we want to give other extensions the chance to modify it).

In the CDI extension, have a @Observes AfterBeanDiscovery method which will be called once after all the beans have been discovered. For each rest client interface:

• Call getAnnotatedTypes() to get the corresponding AnnotatedType.
  • This gets the final AnnotatedType, if it's still there, after all extensions have had the chance to modify it
• Check that it's still a valid rest client interface (remember, another extension may have modified it and made it invalid)
• Create the bean for this rest client interface
  • When a method is called, use the information from the AnnotatedType to check for CDI interceptor bindings (you can either extract this information now, or store the AnnotatedType in your bean class and extract it later

Side note: although we should use AnnotatedType for the interceptor bindings, we should still use reflection to find the rest client annotations, since rest client can also be used without CDI and we want that to be consistent.