Question

I have a spring controller with multiple spring bean dependencies (autowired services). Each service has also few spring bean dependencies (autowired daos).
For instance, controller login method:

@Controller
@RequestMapping("/")
public class ClientAccessController extends BaseController {

    @Autowired
    IFileService fileService;

    @Autowired
    MidTierService midTierService;

    /**
     * Used to handle client login requests
     * Works as a proxy to MID tier server
     *
     * @param request LoginRequest(userLogin, userPassword, compId, installGuid)
     * @return LoginResponse (token)
     * @throws Exception
     */
    @RequestMapping(method = RequestMethod.POST, value = "/login", headers = "Content-   type=application/json")
    public ResponseEntity<LoginResponse> login(@RequestBody LoginRequest request) throws Exception {

        log.info("LOGIN REQUEST [ " + request.toString() + " ]");

        String token = midTierService.authenticateNativeClient(request.getLogin(), request.getPassword(), request.getGuId(),
                request.getCompid().toString());
        LoginResponse response = new LoginResponse(token);

        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setContentType(MediaType.APPLICATION_JSON);

        ResponseEntity<LoginResponse> responseEntity = new ResponseEntity<>(response, HttpStatus.OK);

        log.info("LOGIN RESPONSE [ " + response.toString());

        return responseEntity;
    }

I am trying to write JUnit tests for only controller ClienAccessController. But when I autowire ClientAccessController in test class, spring tries to create beans for all controller dependencies and all nested ones (daos etc) but I really don’t need em, only MidTierService.
So what should I do to exclude nested beans initializations and to use only what I need in test classes?

Answer 1

Spring allows more than one way to @Autowired members. The perferred approach for me (from a testability standpoint) is to @Autowired the constructor. So I would create a constructor for ClientAccessController that looks like this:

@Autowired
public ClientAccessController(final IFileService fileService, final MidTierService midTierService) {
    this.fileService = fileService;
    this.midTierService = midTierService;
}

If your autowiring is a bit more complex (in that it uses @Qualifier or @Value) more can be done with parameter annotations.

@Autowired
public ClientAccessController(@Qualifier("myFileService") final IFileService fileService,
       @Qualifier("myMidTierService") final MidTierService midTierService) {
    this.fileService = fileService;
    this.midTierService = midTierService;
}

That way, you can easily set up this class with mock objects or stubs for testing.

@Test
public void testClientAccessController() {
    final IFileService mockFileService = Mockito.mock(IFileService.class);
    final MidTierService mockMidTierService = Mockito.mock(MidTierService.class);
    final ClientAccessController controller = new ClientAccessController(mockFileService, mockMidTierService);
    //test it
}