feat:乐团费用改造

mec-biz/src/main/java/com/ym/mec/biz/service/impl/ClassGroupServiceImpl.java

@@ -1919,7 +1919,7 @@ public class ClassGroupServiceImpl extends BaseServiceImpl<Integer, ClassGroup>
                 imFeignService.groupJoin(new ImGroupModel(classGroupId.toString(), imGroupMembers, classGroup.getName()));
             });
         }
-        if (classGroup4MixDtos.get(0).getCourseAddType().equals("onlyUpdateTeacher")) {
+        if (Objects.nonNull(classGroup4MixDtos.get(0).getCourseAddType())&&classGroup4MixDtos.get(0).getCourseAddType().equals("onlyUpdateTeacher")) {
             List<Integer> classGroupIds = new ArrayList<Integer>();
             classGroupIds.add(classGroupId);
             // 删除历史记录