Allow @Schema annotation to set an attribute as not required even if it's annotated with @NotNull

[dkotvan]

Is your feature request related to a problem? Please describe.
In our APIs we have parameters which are not required but if they are sent they should not be null. We need they to not be required but not being nullable.

Example ( in Kotlin ):

class PostRequest(
     ..... 
    @field:Schema(required = false, description = COLLATERALS_DESCRIPTION, defaultValue = "[]")
    @field:NotNull
    val collaterals: List<CollateralRequest> = listOf()
)

In this example the field collaterals is initialized with an empty array if it was not present in the request body but if the client send it it should not be null.

The generated OpenAPI is something like this:

schema:
  components:
    PostRequest:
      type: object
      required:
        - collaterals
      properties:
        collaterals:
          $ref: "#schema/components/#CollateralRequest"

But it should be:

schema:
  components:
    PostRequest:
      type: object
      properties:
        collaterals:
          $ref: "#schema/components/#CollateralRequest"

Because we put required = false at the schema annotation.

Describe the solution you'd like
I would like that the required attribute of the schema annotation had precedence before the @NotNull or even that the non-nullable types in Kotlin

Describe alternatives you've considered
I didn't found an alternative

[bnasslahsen]

Hi @dkotvan,

You will be able to use ParameterCustomizer, and override @NotNull behaviour with v1.2.33, as follow:

@Component
public class ParameterCustomizer implements org.springdoc.core.customizers.ParameterCustomizer {
	@Override
	public Parameter customize(Parameter parameterModel, java.lang.reflect.Parameter parameter, HandlerMethod handlerMethod) {
		NotNull annotation = parameter.getAnnotation(NotNull.class);
		if (annotation != null) {
			parameterModel.required(false);
		}
		return parameterModel;
	}
}

[dkotvan]

Thanks, @bnasslahsen