[FIXED] Spring Boot JUnit5: TypeCast Mocking

Issue

Consider the below code,

JAXBElement<Response> jaxb=(JAXBElement<Response>) service.getResponse("abc",2000); //getResponse return an Object.

Response resp=jaxb.getValue(); // Null Pointer Exception

Now in JUnit I am mocking the "service.getResponse(...)"

@Mock
Service service;

when(service.getResponse(anyString(),anyInt()).thenReturn(new Response("value"));

Why am I getting NullPointerException here? Is this not the way to mock the given line?

Solution

You have to mock the response aswell.

JAXBElement<Response> jaxb=(JAXBElement<Response>) service.getResponse("abc",2000); //getResponse return an Object.

Response resp=jaxb.getValue(); // Null Pointer Exception

Junit here,

@Mock
Service service;

JAXBElement response = mock(JAXBElement.class);
when(service.getResponse(anyString(),anyInt()).thenReturn(response);
when(response.getValue()).thenReturn(something);

Answered By - Pirate
Answer Checked By - Katrina (JavaFixing Volunteer)