Body is empty when using MockMvc

> @RunWith(SpringRunner.class) @WebMvcTest(CustomerController.class)
> public class CustomerControllerMvcTest {
> 
>   @Autowired  private WebApplicationContext wac;
> 
>   private MockMvc mockMvc;
> 
>   @MockBean   private ICustomerService customerService;
> 
>   @Before     public void before() {      MockitoAnnotations.initMocks(this);
>       this.mockMvc =
> MockMvcBuilders.webAppContextSetup(this.wac).dispatchOptions(true).build();
>   }
> 
>   @Test   public void getTaskByUserdId1() throws Exception {      String
> expectedOutput = "{\"id\":3,\"name\":\"vikas\"}";         this.mockMvc
>               .perform(
>                       MockMvcRequestBuilders.get("/customer/get/vikas").accept(MediaType.APPLICATION_JSON_UTF8_VALUE))
>               .andExpect(status().isOk()).andExpect(content().string(expectedOutput));
>   }
> 
>   @Test   public void getTaskByUserdId2() throws Exception {      String
> expectedOutput = "{\"id\":3,\"name\":\"vikas\"}";
>       this.mockMvc.perform(get("/customer/get/vikas")).andDo(print()).andExpect(status().isOk())
>               .andExpect(content().string(containsString(expectedOutput)));   } }

It always gives empty body:

> MockHttpServletRequest:
>       HTTP Method = GET
>       Request URI = /customer/get/vikas
>        Parameters = {}
>           Headers = {}
> 
> MockHttpServletResponse:
>            Status = 200
>     Error message = null
>           Headers = {}
>      Content type = null
>              Body = 
>     Forwarded URL = null    Redirected URL = null
>           Cookies = []

It is working fine when i use TestRestTemplate. But, when I use MockMvc and @MockBean, it always gives empty output. I have also used com.gargoylesoftware.htmlunit.WebClient. But, that also gives empty body. I don't know what is happening. Please help. Is it a version issue or i am doing something wrong? Spring boot version: 1.5.10