update

src/main/java/com/qmth/exam/reserve/service/impl/StudentApplyServiceImpl.java

@@ -98,6 +98,8 @@ public class StudentApplyServiceImpl extends ServiceImpl<StudentApplyDao, Studen
         }
         if (req.getTeachingId() != null) {
             List<CategoryVO> listExamSite = examSiteService.listExamSite(req.getTeachingId(), Boolean.FALSE);
+            if(listExamSite.isEmpty())
+                return new PageResult<>();
             List<Long> examSiteIds = listExamSite.stream().map(CategoryVO::getId).collect(Collectors.toList());
             if (!examSiteIds.isEmpty()) {
                 req.setExamSiteIds(examSiteIds);