fix

zhongzheng-system/src/main/java/com/zhongzheng/modules/grade/service/impl/ClassGradeUserServiceImpl.java

@@ -1929,7 +1929,9 @@ public class ClassGradeUserServiceImpl extends ServiceImpl<ClassGradeUserMapper,
                     classPeriodVo.setStatus(userPeriodStatusVo.getStatus());
                     classPeriodVo.setNumList(Convert.toLong(userPeriodStatusVos.size()));
                     classPeriodVo.setStudyEndTime(userPeriodStatusVo.getRecordEndTime());
-                    classPeriodVo.setStudyStartTime(photoList.get(0).getCreateTime());
+                    if(photoList.size()>0){
+                        classPeriodVo.setStudyStartTime(photoList.get(0).getCreateTime());
+                    }
                     if(startTotalTime==0L||startTotalTime.longValue()>classPeriodVo.getStudyStartTime().longValue()){
                         startTotalTime = classPeriodVo.getStudyStartTime();
                     }