please support optionally null parameters in finder endpoints [DATAREST-90]

Josh Long opened DATAREST-90 and commented

For example, suppose i have the following repository:

import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.repository.annotation.RestResource;

import java.util.List;

@RestResource(path = "users", rel = "users")
public interface UserRepository extends PagingAndSortingRepository<User, Long> {
User findByUsername(@Param ("username") String username);
List<User> findUsersByFirstNameOrLastNameOrUsername( @Param ("firstName") String firstName, @Param("lastName") String lastName, @Param("username") String username);
}

if i use the endpoint and specify all the parameters, everything works. http://localhost:8080/users/search/findUsersByFirstNameOrLastNameOrUsername?firstName=X&username=Y&lastName=Z, but fails when one of the query parameters are missing.

No further details from DATAREST-90

Start with the Spring Data REST finder endpoint shown in the issue and trace how repository query parameters are handled when a parameter is absent. Reproduce the example using findUsersByFirstNameOrLastNameOrUsername with one or more missing parameters. Done means the finder endpoint accepts omitted parameters instead of failing while preserving the existing behavior when all parameters are supplied.