Micronaut for Spring Boot ignores path on @RestController

[mikaelvik]

I've created an example project using Micronaut to generate OpenAPI yaml for a Spring Boot application.

Micronaut seems to ignore the path specified on @RestController annotations when generating the yaml file.

The only Swagger annotation I've used is @OpenAPIDefinition on the Micronaut application class (and I'd like to keep it that way).

Controller:

@RestController
@RequestMapping("/api/goodbyes") // edited
public class GoodbyeRestController {

    @GetMapping("/{name}")
    Map<String, String> goodbye(@PathVariable String name) {
        return Collections.singletonMap("goodbye", name);
    }
}

Excerpt from openapi.gradle (applied by build.gradle):

sourceSets {
    openapi {
        compileClasspath += sourceSets.main.compileClasspath
        java {
            srcDirs = [
                'src/main/java',
                'src/openapi/java'
            ]
        }
    }
}

Application class:

@OpenAPIDefinition(info = @Info(title = "mvik-openapi-microboot", version = "0.1"))
public class MicronautApplication {

    public static void main(String[] args) {
        Micronaut.run(MicronautApplication.class);
    }
}

Output:

openapi: 3.0.1
info:
  title: mvik-openapi-microboot
  version: "0.1"
paths:
  /{name}:
    get:
      operationId: goodbye
      parameters:
      - name: name
        in: path
        required: true
        schema:
          type: string
      responses:
        default:
          description: goodbye default response
          content:
            application/json:
              schema:
                type: object
                additionalProperties:
                  type: string

[graemerocher]

According to https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RestController.html

The value of @RestController represents the bean name in Spring and not the URI. I believe to get the behaviour you want have to use:

@RestController
@RequestMapping("/api/goodbyes")

[mikaelvik]

Sorry for the terrible example code, the problem is also there when using @RequestMapping. I've used the same approach on an existing work project where all the @RequestMapping paths were ignored.

I've changed the example code, and the path is still being ignored.

[mikaelvik]

The example uses Micronaut 1.3.1 and Spring Boot 2.2.4.RELEASE.

[graemerocher]

From the looks of this, it seems that Micronaut Spring turns @RequestMapping into Micronaut's @UriMapping here https://github.com/micronaut-projects/micronaut-spring/blob/master/spring-web-annotation/src/main/java/io/micronaut/spring/web/annotation/RequestMappingAnnotationMapper.java#L85

Micronaut OpenAPI only considers the @Controller annotation though unfortunately https://github.com/micronaut-projects/micronaut-openapi/blob/master/openapi/src/main/java/io/micronaut/openapi/visitor/OpenApiControllerVisitor.java#L142

So the fix would be to also consider @UriMapping I imagine.

PRs welcome.

[graemerocher]

In fact since @Controller is an alias for @UrlMapping in Micronaut https://github.com/micronaut-projects/micronaut-core/blob/7f48aac4c8090974e56d1cc89830cb6b201dc1d2/http/src/main/java/io/micronaut/http/annotation/Controller.java#L58

Probably only @UriMapping needs to be considered

[mikaelvik]

I'll give it a try. Thanks for the feedback.

[mikaelvik]

PR created: #150

[mikaelvik]

The fix worked on my example project, that's at least something. Thanks for the pointers.

[graemerocher]

@mikaelvik you can try the just release 1.4.0 version in your project. Let us know how it goes. Hope you write a blog post about what you are doing, seems really interesting :)

[mikaelvik]

@mikaelvik you can try the just release 1.4.0 version in your project. Let us know how it goes. Hope you write a blog post about what you are doing, seems really interesting :)

The release worked perfectly, thanks. Looking forward to the next final release of Micronaut.

I'm not much of a blogger, but I'd be happy to contribute with a section to the docs. The idea is to use a separate source set for the openapi stuff to avoid leaking dependencies into the classpath of the Spring Boot application.

[graemerocher]

@mikaelvik sounds good