hibernate联结的子表无法update,该如何解决

hibernate联结的子表无法update
这里能取到_evaluatescholarship，然后里面的子表也都取到了，但是更新不上去，不晓得为啥。。。。。用的更新函数是已经写好的

Java code

public String editStuScholarship() {        String currentTime = TimeGenerator.getCurrentTime();        try {            Evaluatescholarship _evaluatescholarship = this.evaluateScholarshipService.findById(evaluatescholarship.getEno());            if (null == _evaluatescholarship) {                return "input";            }            Stubasicinfo stubasicinfo = _evaluatescholarship.getStubasicinfo();            Rewardsys rewardsys = _evaluatescholarship.getRewardsys();            Majorinfo majorinfo = _evaluatescholarship.getStubasicinfo().getMajorinfo();            stubasicinfo.setStbStuNo(evaluatescholarship.getStubasicinfo().getStbStuNo());            stubasicinfo.setStbName(evaluatescholarship.getStubasicinfo().getStbName());            stubasicinfo.setSyear(evaluatescholarship.getStubasicinfo().getSyear());            majorinfo.setMname(evaluatescholarship.getStubasicinfo().getMajorinfo().getMname());            rewardsys.setRrank(evaluatescholarship.getRewardsys().getRrank());            stubasicinfo.setMajorinfo(majorinfo);            _evaluatescholarship.setStubasicinfo(stubasicinfo);            _evaluatescholarship.setRewardsys(rewardsys);            //_evaluatescholarship.setStubasicinfo(stubasicinfo)            this.evaluateScholarshipService.update(_evaluatescholarship);                        System.out.println("action getEno = "+id);            logger.info(currentTime + " 用户【" + evaluatescholarship + "】登录:");                //ActionContext.getContext().put("allList", _list);                        if(stuType==1){                    return "success_master";                }                else{                    return "success_doctor";                }        } catch (Exception e) {//            logger.info(" ******************** Method： [execute] ******************** " + //                    "throw an exception,the reason may be username or password is wrong!");            e.printStackTrace();            return "input";        }    }    

Java code

    /**      * 向数据库更新一条对应于一个业务对象实例的记录      *      * @param entity 业务对象实例      */    public void update(Object entity) throws DaoException {        try {            System.out.println("update sucess");            getHibernateTemplate().update(entity);            System.out.println("111");        } catch (DataAccessException e) {            System.out.println("update failed"    );            logger.error("向数据库更新 " + entity.getClass().getName() + " 的记录失败", e);            throw new DaoException("更新 " + entity.getClass().getName()                    + " 实例到数据库失败", e);                    }    }