@Autowired service bean in Controller Class won't recognize the methods

Question

I have this classes:

@Service
public class UserDetailsServiceImpl implements UserDetailsService {


@Autowired
private UserRepository userRepository;
@Autowired
private BCryptPasswordEncoder passwordEncoder;
@Autowired
private EntityManager entityManager;

    @Override
    public UserDetails loadUserByUsername( String username) throws UsernameNotFoundException {
        Optional<User> userOptional = userRepository.findUserByUsername(username);
        User user = userOptional.orElseThrow(
                ()->new UsernameNotFoundException("Username not found in the database")
        );
        return new MyUserDetails(user);
    }
    

 public void saveUser(User user){

User newUser=new User();
newUser.setUsername(user.getUsername());
newUser.setPassword(passwordEncoder.encode(user.getPassword()));
newUser.setEnabled(true);
newUser.setRoles(List.of(entityManager.find(Role.class,1)
));
userRepository.save(newUser);
    }

    public void deleteUser(User user){
        userRepository.delete(user);
    }

public UserDetails getCurrentlyLoggedUser(Authentication authentication){
   Object principal = authentication.getPrincipal();
   if(principal instanceof UserDetails){
       String username=((User) principal).getUsername();
       UserDetails loggedUser = loadUserByUsername(username);
       return loggedUser;
   }

   return null;


}}

@Controller
@RequiredArgsConstructor
public class OrderController {

    private final OrderService orderService;
@Autowired
    private final UserDetailsService userDetailsService;


    @GetMapping("/orderlist")
    public String showOrdeList(Model model, @AuthenticationPrincipal Authentication authentication){
userDetailsService.getCurrentlyLoggedUser

    }
}

I want to know why the methods from UserDetailsServiceImpl class won't show up in the controller... I can acces only the methods from the interface, but not the ones implemented besides them. I tried to use qualifiers, and even made a config class to instantiate the impl class when injecting the bean by interface.

@Configuration
public class OrderConfig {

    @Bean("userDetailsService")
    public UserDetailsService userDetailsService() {
        return new UserDetailsServiceImpl();
    }

Can anyone tell me what I'm doing wrong?

Answer 1

Methods defined in UserDetailsServiceImpl but not in UserDetailsService aren't accessible because you're injecting your service by interface UserDetailsService and compiler doesn't know which implementation will be injected in runtime.

So, you need to define your own interface with all methods that you want to expose or inject your service by class.

@Autowired
private final UserDetailsServiceImpl userDetailsService;

I would recommend a custom interface that extends UserDetailsService and injecting your service using your custom interface.