writing negative unit test cases for controller classes :springboot

Is there a way i could write some negative test cases for the controller class

@RestController
@RequestMapping(value = "/health")
@Api(value = "EVerify Health check API", description = "Health check API")
public class HealthStatusController {

    @Autowired
    @Qualifier("implementation")
    private HealthStatus healthStatus;

    @RequestMapping(value = "", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})
    @ApiOperation(value = "Get the health status of the API", response = ResponseEntity.class)
    public @ResponseBody
    ResponseEntity getHealth() {
        Integer status = healthStatus.healthCheck();
        if (status == 200)
            return ResponseEntity.status(HttpStatus.OK).build();
        else
            return ResponseEntity.status(HttpStatus.ACCEPTED).build();
    }
}

I have written a positive test case as below

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class HealthStatusControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Autowired
    @Qualifier("implementation")
    private HealthStatus healthStatus;

    @InjectMocks
    private HealthStatusController healthStatusController;

    @Rule public ExpectedException exception = ExpectedException.none();

    @Before
    public void setUp() throws Exception {
        mockMvc = MockMvcBuilders.standaloneSetup(healthStatusController).build();
    }

    @Test
    public void getHealthCheckReturns200Test() throws Exception {
        exception.expect(Exception.class);

        Mockito.when(healthStatus.healthCheck()).thenReturn(200);
        mockMvc.perform(get("/health")).andExpect(status().isOk()).andReturn();
    }
}

Appreciate your help.

You can mock HealthStatus with different status

Mockito.when(healthStatus.healthCheck()).thenReturn(500);
mockMvc.perform(get("/health")).andExpect(status().is(500)).andReturn();

You might need to add a @Spy

@Spy
@Autowired
@Qualifier("implementation")
private HealthStatus healthStatus;