我的action是这么写的：
public void modifyTimeTable(){
TimetableDAO timetableDAO = new TimetableDAO();
Timetable timeTable = new Timetable(timeTableI,semesterN,teacherN,classN,classR,courseN,startW,endW,startT,endT,realWeekD);
timetableDAO.attachDirty(timeTable);
}