无法在Spring RestTemplate中模拟JSON响应

@RestController
public class MyController {
    @GetMapping("/data")
    public MyData getData() {
        return new MyData("example");
    }
}

RestTemplate restTemplate = new RestTemplate();
List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
messageConverters.add(new MappingJackson2HttpMessageConverter());
restTemplate.setMessageConverters(messageConverters);

public class MyData {
    private String value;

    public MyData(String value) {
        this.value = value;
    }

    public String getValue() {
        return value;
    }
}

@RunWith(MockitoJUnitRunner.class)
public class MyServiceTest {
    @Mock
    private RestTemplate restTemplate;

    @InjectMocks
    private MyService myService;

    @Test
    public void testGetData() {
        MyData expectedData = new MyData("mockedValue");
        when(restTemplate.getForObject(anyString(), eq(MyData.class))).thenReturn(expectedData);

        MyData result = myService.getData();

        assertEquals(expectedData.getValue(), result.getValue());
    }
}