Spock测试用例在测试其余端点时失败，并出现NullPointer异常

Question

嗨，我是spock测试的新手，所以几乎不需要帮助，我想测试我的控制器，但是我在控制器的方法上得到了空指针异常，这是一种自动装配服务，以下是我的代码

我的控制器

 public class MyController {

  @Autowired
  private MyMapper myMapper;

  @ApiResponses(value = {
    @ApiResponse(code = 201, message = "Created", response = Message1.class),
    @ApiResponse(code = 202, message = "Accepted", response = Message2.class),
    @ApiResponse(code = 400, message = "Bad Request", response = Error.class),
    @ApiResponse(code = 500, message = "Internal Server Error")})
  @PostMapping(path = "/initiation")
  public ResponseEntity initiate(@RequestBody @Valid Message1 message1) {

    Message2 message2 = myMapper.mapToMessage(message1, "Status1", "Status2");

    return ResponseEntity.status(HttpStatus.ACCEPTED).body(message2);


  }
}

我的测试用例

class MyControllerTest extends spock.lang.Specification {

  MyController myController;
  MockMvc mockMvc;
  ObjectMapper objectMapper = new ObjectMapper();
  String jsonstring;
  Message1 message1;

  def setup(){
    paymentController = new PaymentController()
    mockMvc = MockMvcBuilders.standaloneSetup(myController).build()
    //language=JSON
    jsonstring = "{'key':'value'} ";
    message1 = objectMapper.readValue(jsonstring,Message1.class)
  }

  def "response should be 201 when request is valid"(){
    given:
    myController.initiate(message1)

    when:
    ResponseEntity responseEntity = paymentController.initiate(message1);

    then:
    responseEntity.statusCode == CREATED
  }
}

执行测试用例时，我将myMapper对象设置为null 。 您在编写测试用例时可以提供帮助吗？ 怎么了？ 通过邮递员测试时，我的应用程序运行正常 。