使用Mockito测试@Postconstruct

Question

Why when I injecting mocks via Mockito my @Postconstruckt method is not calling?

@Service
public class MyService {
    public MyService() {
        System.out.println("CONSTRUKTOR");
    }

    @PostConstruct
    public void init() {
        System.out.println("POST CONSTRUCT");
    }

@RunWith(MockitoJUnitRunner.class)
public class Mockito1 {

    @InjectMocks
    private MyService service;

    @Before
    public void init() {
    }

Output: Only: CONSTRUKTOR

Answer 1

Because PostConstruct is only spring concept. But you can call postConstruct manually.

 @Before public void prepare() { MockitoAnnotations.initMocks(this); this.service.init(); //your Injected bean } 

Answer 2

@PostConstruct is an annotation defined by JSR 250 and it will be ignored in your current test cause you are using @RunWith(MockitoJUnitRunner.class) , ie, A JUnit runner that is not aware of this annotation. If you are writing unit tests they should be simple ad just test the business logic of your application, but if you want to write integrations tests that use some third-party code that is able to process this kind of annotation, like Spring, for example. Then you can annotate your test class with following annotations:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {AppConfig.class})

Answer 3

I modified a little your service by adding a method foo:

@Service
public class MyService {
    public MyService() {
        System.out.println("CONSTRUKTOR");
    }

    @PostConstruct
    public void init() {
        System.out.println("POST CONSTRUCT");
    }

    public String foo() {
        return "bar";
    }
}

If you want to get behaviour, that you described, there are at least two possibilities:

1. @RunWith(SpringJUnit4ClassRunner.class) + @Autowired - that combination will let you to get a usual service in your test

    @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = MyService.class) public class Mockito1 { @Autowired private MyService service; @Before public void init() { } @Test public void name() throws Exception { System.out.println(service.foo()); } } 

This code will print:

CONSTRUKTOR
POST CONSTRUCT
bar

2. @RunWith(SpringJUnit4ClassRunner.class) + @SpyBean - that combination will let you to get a service in your test and to modify it's behaviour using Mockito

    @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = MyService.class) public class Mockito1 { @SpyBean private MyService service; @Before public void init() { } @Test public void name() throws Exception { System.out.println(service.foo()); Mockito.when(service.foo()).thenReturn("FOO"); System.out.println(service.foo()); } } 

This code will print:

CONSTRUKTOR
POST CONSTRUCT
bar
FOO