我有使用方法payWorkOrder（）的PaymentPresenter。该方法接受一些参数，并根据逻辑创建了两个新对象：

1. WoPayment
2. PaymentRequest

这是代码：

@RunWith(PowerMockRunner.class) @PrepareForTest({TextUtils.class})
public class PaymentPresenterTest extends BaseTest {

@Rule TrampolineschedulerRule trampolineschedulerRule = new  TrampolineschedulerRule();

@Mock CustomersRepository customersRepository;
@Mock Agreementsrepository agreementsrepository;
@Mock WorkOrdersRepository workOrdersRepository;
@Mock PaymentPresenter.View view;
@Mock ResponseBody responseBody;

private PaymentPresenter presenter;

@Before public void setUp() {
mockTextUtils();
presenter = new PaymentPresenter(customersRepository,agreementsrepository,workOrdersRepository);
presenter.setView(view);
}

public void payWorkOrderInvoice(int workOrderId,double amount,String paymentMethod,String checkNumber) {
disposables = RxUtil.initDisposables(disposables);

WoPayment woPayment = new WoPayment();

if(amount > 0) {
  woPayment.setamount(amount);
} else {
  view.displayAmountShouldBeGreaterThanZero();
  return;
}

if(TextUtils.isEmpty(paymentMethod)) {
  view.displayPaymentMethodInvalid();
  return;
} else {
  woPayment.setPaymentMethod(paymentMethod);
}

if(paymentMethod.equalsIgnoreCase("Check") && TextUtils.isEmpty(checkNumber)) {
  view.displayReferenceNumberError();
  return;
} else {
  woPayment.setCheckNumber(checkNumber);
}

view.disablePayButton();

Disposable disposable = workOrdersRepository.payWorkOrderInvoice(workOrderId,new PaymentRequest(woPayment))
    .subscribeon(Schedulers.io())
    .observeon(AndroidSchedulers.mainThread())
    .subscribe(response -> {
      if(response.isSuccessful()) {
        view.displayWorkOrderInvoicePaid(response.body());
      } else {
        view.enablePayButton();
        view.displayWorkOrderInvoiceNotPaid();
      }
      },throwable -> {
      view.enablePayButton();
      view.handleError(throwable);
    });

disposables.add(disposable);
}
}
}

这是我的单元测试：

@Test public void shouldPayWorkOrderInvoice() {
// Given
int workOrderId = 1;
double amount = 1.0;
String paymentMethod = "cash";
String checkNumber = "1";
WorkOrderDetails workOrderDetails = Mockito.mock(WorkOrderDetails.class);
Response<WorkOrderDetails> response = Response.success(200,workOrderDetails);
WoPayment woPayment = new WoPayment();
woPayment.setamount(amount);
woPayment.setCheckNumber(checkNumber);
woPayment.setPaymentMethod(paymentMethod);
PaymentRequest paymentRequest = new PaymentRequest(woPayment);

// When
Mockito.when(workOrdersRepository.payWorkOrderInvoice(workOrderId,paymentRequest)).thenReturn(Single.just(response));
presenter.payWorkOrderInvoice(workOrderId,amount,paymentMethod,checkNumber);

// Then
Mockito.verify(view).displayWorkOrderInvoicePaid(workOrderDetails);
}

但是它失败并显示以下堆栈跟踪：

  

java.lang.NullPointerException在   com.test.presentation.agreements.payment.PaymentPresenter.payWorkOrderInvoice（PaymentPresenter.java:168）     在   com.test.presentation.agreements.PaymentPresenterTest.shouldPayWorkOrderInvoice（PaymentPresenterTest.java:175）     在sun.reflect.NativeMethodaccessorImpl.invoke0（本机方法）处   sun.reflect.NativeMethodaccessorImpl.invoke（NativeMethodaccessorImpl.java:62）     在   sun.reflect.DelegatingMethodaccessorImpl.invoke（DelegatingMethodaccessorImpl.java:43）     在java.lang.reflect.Method.invoke（Method.java:498）在   org.junit.internal.runners.TestMethod.invoke（TestMethod.java:68）在   org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl $ PowerMockJUnit44MethodRunner.runTestMethod（PowerMockJUnit44RunnerDelegateImpl.java:310）     在   org.junit.internal.runners.MethodRoadie $ 2.run（MethodRoadie.java:89）     在   org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters（MethodRoadie.java:97）     在   org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl $ PowerMockJUnit44MethodRunner.executeTest（PowerMockJUnit44RunnerDelegateImpl.java:294）     在   org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl $ PowerMockJUnit47MethodRunner.executeTestInSuper（PowerMockJUnit47RunnerDelegateImpl.java:127）     在   org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl $ PowerMockJUnit47MethodRunner.access $ 100（PowerMockJUnit47RunnerDelegateImpl.java:59）     在   org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl $ PowerMockJUnit47MethodRunner $ LastRuleTestExecutorStatement.evaluate（PowerMockJUnit47RunnerDelegateImpl.java:148）     在   com.test.presentation.core.TrampolineschedulerRule $ 1.evaluate（TrampolineschedulerRule.java:21）