How to AutoWire spring beans when using Mockito and Junit?

You are not mocking anything in your code. @InjectMocks sets a class where a mock will be injected.

Your code should look like this

public class PersonServiceTest {

    @InjectMocks
    PersonService personService;

    @Mock
    MockedClass myMock;

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
        Mockito.doReturn("Whatever you want returned").when(myMock).mockMethod;


    }

    @Test()
      public void testPerson() {

         assertThat(personService.method, "what you expect");
      }

Another solution is to use @ContextConfiguration annotation with static inner configuration class like so:

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class)
public class PersonServiceTest {
    @Autowired
    PersonService personService;

    @Before
    public void setUp() throws Exception {
        when(personService.mockedMethod()).thenReturn("something to return");
    }

    @Test
    public void testPerson() {
         assertThat(personService.method(), "what you expect");
    }

    @Configuration
    static class ContextConfiguration {
        @Bean
        public PersonService personService() {
            return mock(PersonService.class);
        }
    }
}

Anyway, you need to mock something that the method you want to test uses inside to get desired behaviour of that method. It doesn't make sense to mock the service you're testing.