Idea Summary
Generate Swagger Doc currently generates Swagger 2.0 documentation. Allow the generation of OpenAPI v3. documentation too.
For more complex Json body input: add an option where the Json schema can be specified. This can then be added to the OpenAPI v3 documentation (instead of just PAYLOAD body of type String).
The same for Json output.
Use Case
The REST definition contains the full specification of Json input and output body.
You don't have to edit the generated code.
It makes it easier for REST consumers to generate code based on OpenAPI v3.