使用 Hibernate 的 update()方法出现奇怪的有关问题

/**     * 自己写的更新记录函数     */    public boolean UpdateOperatorInfo(OperatorInfo operatorinfo){        boolean b=false;        Session session=(Session) this.getSession();        Transaction tron=session.beginTransaction();        try{            OperatorInfo opinfo=new OperatorInfo();            session.load(opinfo, operatorinfo.getOperatorId());            opinfo.setOperatorName(operatorinfo.getOperatorName());            opinfo.setOperatorPwd(operatorinfo.getOperatorPwd());            opinfo.setIsAdmin(operatorinfo.getIsAdmin());            session.update(opinfo);            //session.flush();            tron.commit();            b=true;        }catch(HibernateException e){            if(tron!=null){                tron.rollback();                e.printStackTrace();                            }        }finally{            session.close();        }        return b;    }

<%@ page language="java"  pageEncoding="utf-8" import="pojo.OperatorInfo,pojo.OperatorInfoDAO,java.util.Iterator"%><%request.setCharacterEncoding("utf-8"); %><%    String s_id=request.getParameter("id");     String name=request.getParameter("name");    String pwd=request.getParameter("pwd");    String isno=request.getParameter("isno");        name=name.trim();    pwd=pwd.trim();    isno=isno.trim();            OperatorInfoDAO opdao=new OperatorInfoDAO();    OperatorInfo opinfo=new OperatorInfo();        opinfo.setOperatorId(Integer.parseInt(s_id));    opinfo.setIsAdmin(isno);    opinfo.setOperatorName(name);    opinfo.setOperatorPwd(pwd);        //out.println(opinfo.getOperatorId());    if(opdao.UpdateOperatorInfo(opinfo)){        response.sendRedirect("addoperator.jsp");    }else{        out.println("你必须手动刷新一下本页才能更新成功，为什么，我也不知道");    }        //opdao.attachDirty(opinfo);    //response.sendRedirect("addoperator.jsp");    %>