Merge branch 'zx_2022-11-22' of http://git.dayaedu.com/yonge/mec into master_saas

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

@@ -3669,7 +3669,7 @@ public class ClassGroupServiceImpl extends BaseServiceImpl<Integer, ClassGroup>
                     classGroupTeacherMappers.add(classGroupTeacher);
                 }
                 List<ClassGroupTeacherMapper> classGroupTeacherMapperList = classGroup.getClassGroupTeacherMapperList();
-                if (classGroupTeacherMapperList.size() > 0) {
+                if (!CollectionUtils.isEmpty(classGroupTeacherMapperList)) {
                     List<ClassGroupTeacherMapper> teachingTeachers = classGroupTeacherMapperList.stream().filter(e -> e.getTeacherRole() == TeachTypeEnum.TEACHING).collect(Collectors.toList());
                     if (teachingTeachers.size() > 0) {
                         classGroup.setTeachingTeacherName(StringUtils.join(teachingTeachers.stream().map(e -> e.getUserName()).collect(Collectors.toList()), ","));