java.lang.AssertionError：期望状态：<200>，但之前是：<400>

Question

@Test
public void appFormSubmissionTest() throws Exception {
AppFormSubmissionBOResponse resonse = new ObjectMapper().readValue(
       AppFormSubmissionBOResponse.class.getResourceAsStream("/appFormSubmission_BO_Resp.json"),
       new TypeReference<AppFormSubmissionBOResponse>() {});

Mockito.when(apiCallImpl.invokeSubmitApplicationForm(any(String.class),any(HttpEntity.class))).thenReturn(resonse);

this.mockMvc.perform(MockMvcRequestBuilders.post("/appformsubmission")
            .accept(MediaType.APPLICATION_JSON_VALUE)
            .content(new ObjectMapper().readValue(ChanelRequest.class.getResourceAsStream("/appFormSubmissionChanelRequest.json"),
                                                  new TypeReference<ChanelRequest<AppFormDetails>>() {}).toString())
            .contentType(MediaType.APPLICATION_JSON))               
            .andExpect(status().isOk())
            .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8_VALUE))
            .andExpect(jsonPath("$.payload.dataEntity.pdfUrl", is("")));
}

对于此代码，我得到以下错误。 java.lang.AssertionError：状态应为：<200>，但为：<400>

这是控制器类

@PostMapping(path = "/appformsubmission")
public ChanelResponse<AppFormSubmissionResponse> saveAppForm(
        @RequestBody ChanelRequest<AppFormDetails> requestObject) throws JsonProcessingException {

    logger.info("MwController -saveAppForm ");
    if (logger.isDebugEnabled()) {
        logger.debug("Entering MwController() method");
        logger.debug("requestObject : {}", Utility.toJsonString(requestObject));
    }
    return appFormService.submitApplicationForm(requestObject);
}

请帮助我解决这个问题。