Spring boot async Callable support

[darc1]

Hi,

Springdoc fails to generate the response schema for spring boot controller methods with Callable. (spring boot async support using Callable docs)

For example the controller method:

    @RequestMapping(value = "/tasks", method = RequestMethod.GET)
    private Callable<ResponseEntity<Page<TaskDTO>>> getTasks(
                                                             @RequestParam(required = false) Predicate predicate,
                                                             Pageable pageable) {

        return () -> {

            Page<TaskDTO> fetchResult = fetchService.getTasks(pageable, predicate);
            return new ResponseEntity<>(fetchResult);

        };
    }

I was able to work around it by overriding the calculateSchemaFromParameterizedType method in the ResponseBuilder class, like this:

@ComponentScan(basePackages = {"org.springdoc.core"})
@Configuration
public class SpringDocConfig {

    private final OperationBuilder builder;

    public SpringDocConfig(OperationBuilder builder) {
        this.builder = builder;
    }

    @Bean
    public ResponseBuilder responseBuilder(){
        return new ResponseBuilderWithCallableHandling(builder);
    }


    public class ResponseBuilderWithCallableHandling extends ResponseBuilder{

        ResponseBuilderWithCallableHandling(OperationBuilder operationBuilder) {
            super(operationBuilder);
        }

        @Override
        protected Schema calculateSchemaFromParameterizedType(Components components, ParameterizedType parameterizedType, JsonView jsonView) {
            Schema<?> schemaN = null;

            if (Callable.class.getName().contentEquals(parameterizedType.getRawType().getTypeName())) {
                Type type = parameterizedType.getActualTypeArguments()[0];
                if(type instanceof ParameterizedType){
                    schemaN = super.calculateSchemaFromParameterizedType(components, (ParameterizedType)type, jsonView);
                }else {
                    schemaN = this.calculateSchemaParameterizedType(components, parameterizedType, jsonView);
                }
            }else {
                schemaN = super.calculateSchemaFromParameterizedType(components, parameterizedType, jsonView);
            }

            return schemaN;
        }
    }
}

It would be great if you could add support for Callable in future releases.