Mockito - NullpointerException when stubbing Method

Question

So I started writing tests for our Java-Spring-project.

What I use is JUnit and Mockito. It\'s said, that when I use the when()...thenReturn() option I can mock ser

Answer 1

For future readers, another cause for NPE when using mocks is forgetting to initialize the mocks like so:

@Mock
SomeMock someMock;

@InjectMocks
SomeService someService;

@Before
public void setup(){
    MockitoAnnotations.initMocks(this); //without this you will get NPE
}

@Test
public void someTest(){
    Mockito.when(someMock.someMethod()).thenReturn("some result");
   // ...
}

Also make sure you are using JUnit for all annotations. I once accidently created a test with @Test from testNG so the @Before didn't work with it (in testNG the annotation is @BeforeTest)