update

edu-user/edu-user-biz/src/main/java/com/keao/edu/user/service/impl/ExamRoomServiceImpl.java

@@ -819,7 +819,7 @@ public class ExamRoomServiceImpl extends BaseServiceImpl<Long, ExamRoom> impleme
 			if(StringUtils.isNotEmpty(examRoom.getAssistantTeacherUserIdList())){
 				stringBuffer.append(",").append(examRoom.getAssistantTeacherUserIdList());
 			}
-			imFeignService.joinGroup(studentIds,examRoomId.toString(),examRoomId.toString());
+			imFeignService.joinGroup(stringBuffer.toString(),examRoomId.toString(),examRoomId.toString());
 			PublishMessageDto publishMessageDto = new PublishMessageDto();
 			publishMessageDto.setUserId(sysUser.getId().toString());
 			publishMessageDto.setRoomId(examRoomId.toString());