How to mock non static logger with PowerMock?

Question

I have a class that looks like this:

class Service {
    private final Logger lgr = LoggerFactory.getLogger(Service.class);

    public void doService() {
        lgr.info("Do Service");
    }
}

public class Controller {
    private final Logger lgr = LoggerFactory.getLogger(Controller.class);

    @Autowired
    private Service service;

    protected void doSomething() {
        //do something
        lgr.info("LOG something"); // lgr line
        // do something else

    }
}

And the corresponding test class that looks like this:

@RunWith(PowerMockRunner.class)
@PrepareForTest({ControllerTest.class, LoggerFactory.class})
public class ControllerTest {
    private Controller controller;

    @Mock
    private Service service;

    @Before
    public void init() {
        controller = Mockito.mock(Controller.class, Mockito.CALLS_REAL_METHODS);
    }

    @Test
    public void testDoSomething() {
        controller.doSomething();  // calling doSomething method of Controller class
        // some other statements
    }
}

Here, when the call goes to doSomething() method, at line lgr line, the lgr object is null, due to which my unit test is failing with NullPointerException.

Can someone please, help me fix this?