优化评价导入

sapi/src/main/java/com/xhkjedu/sapi/utils/PoiUtils.java

      **/
     public static String getCellValue(Cell cell){
         String value = null;
+        if (cell == null) return value;
         DecimalFormat df = new DecimalFormat("0");  //格式化number String字符
         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  //日期格式化
         DecimalFormat df2 = new DecimalFormat("0");  //格式化数字
      **/
     public static Map<String, Object> readAssess(MultipartFile file, Integer schoolid, AssessUserService assessService) {
         Map<String, Object> resultMap = new HashMap<>();
+        Map<Integer, List<String>> errMsg = new LinkedHashMap<>();
         try {
             // 数据校验
             isExcelEmpty(file);
 
             // 导入用户信息
             List<TAssessUser> users = new ArrayList<>();
-            Map<Integer, List<String>> errMsg = new LinkedHashMap<>();
             Map<String, Integer> grades = listGrade();
             TSchool school = assessService.getSchoolById(schoolid);
             List<SubjectVo> subject = assessService.listSubject(schoolid, school.getSchoollevel());
 
             resultMap.put("code", 0);
             resultMap.put("users", users);
-            resultMap.put("errMsg", errMsg);
         } catch (Exception e) {
             resultMap.put("code", 1);
             resultMap.put("msg", e.getMessage());
             log.error("读取评价用户出错", e.getMessage());
         }
+        resultMap.put("errMsg", errMsg);
         return resultMap;
     }