我正在嘗試使用 JUnit 為以下控制器代碼編寫測試用例。但是我得到了 500 個帶有空指針異常的代碼。（當我在 Postman 上測試時，它可以正常工作。）我認為 validEmp 的 HttpServeleRequest 請求可能會導致 testGetMethod 出現此空指針異常。任何人都可以告訴我在這里做錯了什么以及如何解決這個問題？謝謝你的幫助:D登錄服務public ReturnParam validEmp(HttpServletRequest request, String locale, String empKey, String accessToken) throws Exception {    ReturnParam rp = new ReturnParam();    rp.setFail("not available");    return rp;}登錄控制器@RequestMapping(value = "/valid", method = RequestMethod.GET, produces = "application/json; charset=UTF-8")public @ResponseBody ReturnParam validEmp(HttpServletRequest request,        @RequestParam(value = "locale", required = true) String locale,        @RequestParam(value = "empKey", required = true) String empKey,        @RequestParam(value = "accessToken", required = true) String accessToken) throws Exception {    return service.validEmp(request, locale, empKey, accessToken);}登錄控制器測試public MockMvc mockMvc;private MediaType contentType = new MediaType(MediaType.APPLICATION_JSON.getType(),        MediaType.APPLICATION_JSON.getSubtype(), Charset.forName("utf8"));public void testGetMethod(String url, String locale, String empKey, String acessToken) throws Exception {    mockMvc.perform(get(url).param("locale", locale).param("empKey",empKey).param("accessToken", acessToken))           .andDo(print())           .andExpect(status().isOk());}