findById

Controller

@GetMapping(value = "/{id}")
public ResponseEntity<UserDTO> findById(@PathVariable String id) {
    UserDTO obj = userService.findById(id);
    return ResponseEntity.ok().body(obj);
}

Service

public UserDTO findById(String id) {
    User user = userRepository.findById(id)
            .orElseThrow(() -> new ResourceNotFound("Recurso não encontrado."));

    return new UserDTO(user);
}