Endpoint with data jpa interface projection

Question

I use spring boot 3

I created a query to get a part of entity via a projection

public interface UserConnexion {

    Long userId();

    String name();

    CatogoryUserCode user();

    interface CatogoryUserCode{
        String code();
    }

}


@Query("""
       select u.userId, u.name, ce.code from User u
       join  u.categoryUserCode ce
        WHERE u.userId=:userId
    """)
public  Optional<UserConnexion> findByIdUserProjection(Long userId);

Query is generated

So i created an endpoint

@GetMapping("/user/{id}")
public ResponseEntity<UserConnexion> findLigtUserById(@PathVariable Long id) {
    return new ResponseEntity<UserConnexion>(userManager.findLigtUserById(id), HttpStatus.OK);

Edit

Method in userManager

@Transactional(readOnly = true)
public UserConnexion findLigtUserById(Long id) {
    return  userRepository.findByIdUserProjection(id).orElseThrow(() -> new EntityNotFoundException(id + " "));
}

When endpoint is called

Resolved [org.springframework.web.HttpMediaTypeNotAcceptableException: No acceptable representation