我有這個非常簡單的控制器類和一個簡單的 (jpa) 存儲庫。我想要做的是測試它的 api 但模擬它的存儲庫并讓它根據測試用例返回或不返回對象。我現在的問題是我不知道該怎么做。我知道如何模擬存儲庫并將其注入控制器/服務類 @Mock / @InjectMocks / when().return()但是當我在用 MockMvc 發出請求后想做同樣的事情時，我失敗了。非常感謝任何幫助控制器import java.util.Optional;@RestController@Slf4jpublic class ReceiptController implements ReceiptsApi {    @Autowired    private ReceiptRepository receiptRepository;    @Autowired    private ErrorResponseExceptionFactory exceptionFactory;    @Autowired    private ApiErrorResponseFactory errorResponseFactory;    @Override    public Receipt getReceipt(Long id) {        Optional<ReceiptEntity> result = receiptRepository.findById(id);        if (result.isEmpty()) {            throw invalid("id");        }        ReceiptEntity receipt = result.get();        return Receipt.builder().id(receipt.getId()).purchaseId(receipt.getPurchaseId()).payload(receipt.getHtml()).build();    }    private ErrorResponseException invalid(String paramName) {        return exceptionFactory.errorResponse(                errorResponseFactory.create(HttpStatus.NOT_FOUND.value(), "NOT_VALID", String.format("receipt with id %s not found.", paramName))        );    }}而且是測試課@WebMvcTest(ReceiptController.class)@RestClientTestpublic class ReceiptControllerTest {    @InjectMocks    private ReceiptController receiptController;    @Mock    private ReceiptRepository receiptRepository;    @Mock    private ErrorResponseExceptionFactory exceptionFactory;    @Mock    private ApiErrorResponseFactory errorResponseFactory;    private MockMvc mvc;    @Before    public void setUp() {        MockitoAnnotations.initMocks(this);        mvc = MockMvcBuilders.standaloneSetup(                new ReceiptController())                      .build();    }