Why doesn't a GET request hit a @GetMapping annotated method with parameters in Spring?

Question

Java

There is a method in the controller that handles the GET request. This method is annotated

@GetMapping(params = {ParameterName.SORT_BY, ParameterName.SORT_TYPE})

. This method in the arguments with the help of an annotation @RequestParambinds the argument that came from the GET request to a Java variable of the String type. It looks like this:

@GetMapping(params = {ParameterName.SORT_BY, ParameterName.SORT_TYPE})
    public List<GiftCertificate> findAllAndSort(@RequestParam(value = ParameterName.SORT_BY) String sortBy,
                                                @RequestParam(value = ParameterName.SORT_TYPE, required = false) String sortType) {
        log.info("Sorting: {}, {}", sortBy, sortType);
        return service.findAllAndSort(sortType, sortBy);
    }

The sortType argument has required = false , which means that this argument does not have to be present:

@RequestParam(value = ParameterName.SORT_TYPE, required = false) String sortType).

Then the question is why when requesting the view:
-

http://localhost:8080/gift-certificates?sort_by=name&sort_type=DESC

the request falls into this method.
-

http://localhost:8080/gift-certificates?sort_by=name

not included in this method.

Answer 1

Because params in @___Mappingis designed to unambiguously bind a request to a method.
I.e,

@GetMapping(params = {ParameterName.SORT_BY, ParameterName.SORT_TYPE})

will be called ONLY if both parameters are present in the url. Whether indicated required = falseor not.