Using @Spy and @Autowired together

Question

I have a Service Class with 3 methods, Service class is also using some @Autowired annotations. Out of 3 methods, I want to mock two methods but use real method for 3rd one.

Problem is:

1. If I am using @Autowired with @Spy, all three real method implementation is being called.
2. If I am using @Spy only, call to real method is return with Null pointer as there is no initialisation of Autowired objects.

Answer 1

I know about these two options:

1. Use @SpyBean annotation from spring-boot-test as the only annotation

@Autowired
@InjectMocks
private ProductController productController;

@SpyBean
private ProductService productServiceSpy;

2. Use Java reflection to "autowire" the spy object, e.g. ReflectionTestUtils

@Autowired
private ProductController productController;

@Autowired
private ProductService productService;

@Before
public void setUp() {
    ProductService productServiceSpy = Mockito.spy(productService);
    ReflectionTestUtils.setField(productController, "productService", productServiceSpy);
}