@mock annotation之后的mock实例为null

Question

我尝试运行此测试：

    @Mock IRoutingObjHttpClient routingClientMock;
    @Mock IRoutingResponseRepository routingResponseRepositoryMock;


    @Test
    public void testSendRoutingRequest() throws Exception {
        CompleteRoutingResponse completeRoutingResponse = new CompleteRoutingResponse();
        completeRoutingResponse.regression_latencyMillis = 500L;

        Mockito.when(routingClientMock.sendRoutingRequest(any(RoutingRequest.class))).thenReturn(completeRoutingResponse);

        RoutingObjHttpClientWithReRun routingObjHttpClientWithReRun = new RoutingObjHttpClientWithReRun
                (routingClientMock, routingResponseRepositoryMock);

...
    }

但是我得到了NullPointer异常：

Mockito.when

我错过了什么？

Answer 1

如果使用Junit5，也会出现同样的问题，因为没有更多的“@RunBy”注释。

在这种情况下，你应该用以下注释你的类：

@ExtendWith(MockitoExtension.class)
public class MyTestClass {
...

您还应该导入到依赖项（Maven-pom.xml）中：

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-junit-jupiter</artifactId>
    <version>${mockito.version}</version>
    <scope>test</scope>
</dependency>

Answer 2

激活@Mock注释有三个选项：MockitoRule、MockitoJUnitRunner、MockitoAnnotations。（这个）。IMHO使用MockitoRule是最好的，因为它仍然允许您选择另一个跑步者，例如参数化的。

public class MockitoTest {

  @Mock
  private IRoutingObjHttpClient routingClientMock;

  @Rule
  public MockitoRule rule = MockitoJUnit.rule();

  @Test
  public void testSendRoutingRequest() throws Exception {
    // ...
  }
}

@RunWith(MockitoJUnitRunner.class)
public class MockitoTest {

  @Mock
  private IRoutingObjHttpClient routingClientMock;

  @Test
  public void testSendRoutingRequest() throws Exception {
    // ...
  }
}

这可以在qn@Before方法中、在您自己的跑步者中或在自己的规则中完成。

public class MockitoTest {

  @Mock
  private IRoutingObjHttpClient routingClientMock;

  @Before
  public void createMocks() {
    MockitoAnnotations.initMocks(this);
  }

  @Test
  public void testSendRoutingRequest() throws Exception {
    // ...
  }
}

Answer 3

当你想使用@Mock注释时，你应该使用MockitoJUnitRunner

@RunWith(MockitoJUnitRunner.class)
public class MockitoTest {

    @Mock
    private IRoutingObjHttpClient routingClientMock;

    @Test
    public void testSendRoutingRequest() throws Exception {
        // ...
    }

}

另请参见本教程。