供参考：

Question

异常

java.lang.NullPointerException 
    at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.addAnswersForStubbing(PowerMockitoStubberImpl.java:67)
    at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.when(PowerMockitoStubberImpl.java:42)
    at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.when(PowerMockitoStubberImpl.java:105)
    at us.ny.state.ij.safeact.ask.facade.AmmoSellerKeeperFacadeBeanTest.setUp(FacadeBeanTest.java:84)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at

代码模拟

BusinessServiceFactory serviceFactory = BusinessServiceFactory.getInstance();
RegBusinessServiceImpl regCreateService = 
    serviceFactory.getRegBusinessService(adrEntityManager);

测试代码

@RunWith(PowerMockRunner.class)
@PrepareForTest({ BusinessServiceFactory.class})
public class FacadeBeanTest {

    @Before
    public void setUp() throws Exception {
        AmmoSellerRegBusinessServiceImpl  mockRegBusinessServiceImpl 
            = mock(AmmoSellerRegBusinessServiceImpl.class);
        PowerMockito.doReturn(mockRegBusinessServiceImpl)
            .when(BusinessServiceFactory.class,"getRegBusinessService",
            (mockEntityManager)); //--- line 84 null pointer exception
    }
}

我无法理解为什么我会看到异常。我很感激任何建议。

Answer 1

您必须使用Mockito.when()来模拟返回值的方法。此外，您需要在模拟静态类的方法之前使用PowerMockito.mockStatic()。

PowerMockito.mockStatic(BusinessServiceFactory.class);
// use Mockito to set up your expectation
Mockito.when(BusinessServiceFactory.getInstance())
    .thenReturn(mockRegBusinessServiceImpl);
Mockito.when(mockRegBusinessServiceImpl.getRegBusinessService())
    .thenReturn(mockEntityManager);

在这里查看PowerMock usage以便更好地理解。

Answer 2

供参考：

解决方案是使用 PowerMockito.mock（）而不是 Mockito.mock（）

你应该做

AmmoSellerRegBusinessServiceImpl  mockRegBusinessServiceImpl 
        = PowerMockito.mock(AmmoSellerRegBusinessServiceImpl.class);

而不是

AmmoSellerRegBusinessServiceImpl  mockRegBusinessServiceImpl 
            = mock(AmmoSellerRegBusinessServiceImpl.class);
// assuming your are using Mockito.mock()
// correct me if I am wrong

我也遇到了同样的问题。这个解决方案对我来说很合适。希望它有所帮助。

org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.addAnswersForStubbing中的java.lang.NullPointerException

2 个答案:

供参考：