Extended support for Spring Controller interfaces

[vghero]

Hey,
I'm using Enunciate 2.11.1 together with a Spring 5 WebMVC REST app. I'm separating the REST controllers via interfaces from its implementation, so that the interface can be reused by client generation like Feign. Recently Feign dropped support for @RequestMapping on Controller interfaces and so I dropped it as well, moving the path to e.g. @GetMapping on method level. Then I also wanted to cleanup @RestController on the interface, as it's already contained on my impl. But then it seemed that enunciate wasn't able to pickup the endpoints anymore on the interface - which I use for "scanning".

Now I'm wondering if there's a way for Enunciate to detect that the interface actually IS a RestController without having that annotation set on it directly - but maybe looking at the implementation class which has it? Does the internal metamodel in Enunciate already has this kind of information?

[stoicflame]

If there are no annotations on the interface itself, how would Enunciate determine whether the interface is actually a controller or if it's just a common interface that multiple controllers want to share?

[vghero]

I agree it's a bit "tricky" and surely does not make it less complex. Naive me thought just looking for the implementation class of the interface. But if we have multiple impls I would expect that all of them will be selected as a target for documentation generation. Similar to what happens with referenced DTOs in an interface - they are also picked up although maybe lying out of the provided package to scan. If this is a bigger thing todo it's maybe not worth the effort....

[stoicflame]

I can take a closer look, but let me summarize to make sure I understand what you'd like to see.

• Currently impl controller classes are getting picked up for documentation by Enunciate, but interfaces are only getting picked up if they're annotated with @RestController.
• You'd like to see Enunciate pick up interfaces as controllers if they have @[Method]Mapping annotations on their methods and if they have an impl class that is annotated with @RestController.

Is that accurate?

[vghero]

Yes, that is accurate :).

[stoicflame]

Okay. We'll probably have to make this a config option, though, because some people use interfaces to support common parameters and patters across multiple controllers and it doesn't imply that the interface is a controller.

For example, if I want my GET method to have the same signature on Resource1Controller, Resource2Controller, etc., then I might define an interface that enforces that GET method signature and is annotated with @GetMapping, even though the interface was never intended to be a controller itself.