有没有办法在spring-data-rest存储库方法上验证方法参数？

Question

For instance, I have a repository class like this.

@RepositoryRestResource
public interface FooRepository extends JpaRepository<Foo, Integer> {

  Optional<Foo> findByBarId(@Param("barId") Integer barId);

}

This generates a search endpoint with path http://hostname/foo/search/findByBarId{?fooId}

When I access this URL without any parameters, I get a 404 which I i think is okay.

However, I would rather send a 400 for this type or errors as my business would definitely need a parameter for this API.

I tried using @javax.validation.constraints.NotNull

Optional<Foo> findByBarId(@Param("barId") @NotNull Integer barId);

as well as @org.springframework.lang.NonNull

Optional<Foo> findByBarId(@Param("barId") @NonNull Integer barId);

Both annotations did not work. Of Course it doesn't work because these annotations by itself is just meta information which is not being taken into account by spring-framework.

The documentation didn't have anything showcased for parameter validation behaviour. (They only speak about entity lifecycle validation )

Is there any straightforward way I can achieve such behaviour?

I use spring-boot 2.0.4 if that helps.

Answer 1

You can write a RepositoryRestController to run specific business to customize your endpoints.

Here is an example for your case, you can customize it as well :

@RepositoryRestController
public class FooController {

    FooRepository fooRepository;

    @Autowired
    public FooController(FooRepository fooRepository) {
        this.fooRepository = fooRepository;
    }

    @GetMapping(path = "/foo")
    public ResponseEntity getfoo(@RequestParam("barId") Optional<Integer> barId) {
        if (!barId.isPresent()) {
            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(null);
        }

        Optional<Foo> foo = fooRepository.findByBarId(barId.get());

        return ResponseEntity.ok(foo);
    }
}