Spring NullPointerException this.service 为 null

问：

我的 NullPointerException 有问题，/register 端点上的每个 POST，NullPointerException 显示服务是带有 /register 的
null 控制器

@AllArgsConstructor
@RestController
@Validated
public class SecurityController {

    private final UserService service;

    @PostMapping("/register")
    private ResponseEntity<UserDTO> registerUser (@RequestBody @Valid RegisterDTO registerDTO) {
        return ResponseEntity.created(URI.create("/user")).body(service.createUser(registerDTO));
    }

用户服务

@RequiredArgsConstructor
@Service
public class UserService implements UserServiceApi {
    private final UserRepository userRepository;
    private final RoleRepository roleRepository;
    private final PasswordEncoder encoder;

    @Override
    public UserDTO createUser(RegisterDTO user) {
        if (user.equals(userRepository.findByUsername(user.getUsername()))) {
            throw new RuntimeException("This nickname is already taken");
        }
        if (user.equals(userRepository.findByEmail(user.getEmail()))) {
            throw new RuntimeException("This email is already taken");
        }
        // Encoding password
        user.setPassword(encoder.encode(user.getPassword()));
        // On creating new Account it's going to have USER role
        Role role = roleRepository.findByName("USER");

        String username = user.getUsername();
        String password = user.getPassword();
        String email = user.getEmail();

        User dto = buildUser(username, password, email, role);

        userRepository.save(dto);
        return UserDTO.builder()
                .username(username)
                .password(password)
                .email(email)
                .build();
    }

其他使用服务的控制器，我不知道这可能是问题的线索

@RestController(value = "/user")
@AllArgsConstructor
@Validated
public class UserController {
    private final UserService service;

    @GetMapping("/getusers")
    public ResponseEntity<List<User>> getAllUser() {
        return ResponseEntity.ok(service.getUsers());
    }