fix 线上课有教学点

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

@@ -1776,11 +1776,11 @@ public class ClassGroupServiceImpl extends BaseServiceImpl<Integer, ClassGroup>
 
         MusicGroup musicGroup = musicGroupDao.get(classGroup.getMusicGroupId());
 
-        Integer schoolId = musicGroup.getSchoolId();
+        Integer schoolId = teachMode.equals(TeachModeEnum.ONLINE)? null : musicGroup.getSchoolId();
 
         List<Subject> subjectList = subjectService.findBySubjectByIdList(classGroup.getSubjectIdList());
 
-        String subjectNames = subjectList.stream().map(subject -> subject.getName()).collect(Collectors.joining("/"));
+        String subjectNames = subjectList.stream().map(Subject::getName).collect(Collectors.joining("/"));
 
         //1、更新班级关联老师信息
         List<ClassGroupTeacherMapper> newClassGroupTeacherMapperList = classGroup4MixDto.getClassGroupTeacherMapperList();