@RequestBody annotation on interface methods ignored for required flag

[renatomameli]

When @RequestBody(required = false) is declared on a controller interface method, Spring currently ignores this annotation during request mapping. As a result, mappings incorrectly require a request body even when required = false is set on the interface.

This leads to incorrect matching behavior, especially when the implementation method does not override the @RequestBody annotation.

Expected behavior:
Spring should detect the @RequestBody annotation on interface methods and respect the required flag during request mapping, allowing requests without bodies when required = false.

Actual behavior:
Only the annotations on the implementation method are considered, causing required = false on interfaces to be ignored.

Steps to reproduce:

• Define a controller interface method annotated with @RequestBody(required = false)
• Implement the interface without overriding the annotation
• Register the handler and observe that Spring expects a body even if required = false
• Make a request with no body and no Content-Type and observe that the request fails

Suggested fix:
Use AnnotatedMethod to retrieve parameter annotations from both implementation and interface methods to correctly determine the required flag.

Additional context:
I have a patch that fixes this and adds tests to cover both interface and implementation overrides.

[sbrannen]

Hi @renatomameli,

Congratulations on submitting your first issue for the Spring Framework.

Unfortunately, we do not need both an issue and a PR for the same topic.

Thus I am closing this as a:

• Superseded by Support @RequestBody in interface method when computing "consumes" condition #35086