修改密码环节无法获取staff对象信息

package com.imooc.sm.controller;

import com.imooc.sm.entity.Staff;
import com.imooc.sm.service.SelfService;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;


@Controller("selfController")
public class SelfController {
   @Autowired
   private SelfService selfService;
   /**/
   public void toLogin(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

       //注意这里的页面表达 之前都是"../staff_list.jsp"
       //这里"login.jsp"
       //因为这里是一级目录
       request.getRequestDispatcher("login.jsp").forward(request, response);
   }
   public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

      //首先接收用户传递过来的值
       String account =request.getParameter("account");
       String password=request.getParameter("password");
       //调用业务层的login方法,将返回给staff对象
       Staff staff =selfService.login(account,password);
       //如果成功返回一个staff  如果失败返回null
       if (staff==null){
         response.sendRedirect("toLogin.do");
       }else{
           //返回staff 存放在session中
           HttpSession session=request.getSession();
           //以大写的USER为键接收
           session.setAttribute("USER",staff);
           response.sendRedirect("main.do");
       }


   }
   public void logout(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {


           //返回staff 存放在session中
           HttpSession session=request.getSession();
           //以大写的USER为键接收，退出系统将值赋为空
           session.setAttribute("USER",null);
           response.sendRedirect("toLogin.do");


   }

   public void main(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {


       request.getRequestDispatcher("index.jsp").forward(request, response);
   }
   //这个是再self/info.do
   public void info(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

       request.getRequestDispatcher("../info.jsp").forward(request, response);
   }
   //修改密码  由两部分完成一部分是打开修改的界面，另外就是修改的流程
   public void toChangePassword(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

       request.getRequestDispatcher("../change_password.jsp").forward(request, response);
   }
   public void changePassword(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       String password=request.getParameter("password");

       String password1=request.getParameter("password1");

       HttpSession session=request.getSession();

       Staff staff=(Staff)request.getAttribute("USER");
       System.out.println(staff);



       if (!staff.getPassword().equals(password)){

           System.out.println("判断成功");
           response.sendRedirect("../toChangePassword.do");

       }else {
           System.out.println("判断成功");

           selfService.changepassword(staff.getId(),password1);
           //然后进行跳转到新的页面
           //response.sendRedirect("toLogin.do");
           //如果直接跳转，session中还有当前用户的信息
           //所以跳转到logout.do中
           //response.sendRedirect("../logout.do");
           //因为这里做的是再右下角的窗体中做的，再这部分中无法实现整体页面的跳转
           //若如此做，左边和顶部的信息仍然再，将再右下角的窗口中重新打开一个登陆界面
           //所以需要将整个网页全部重定向回登陆界面，这里要用到javascript

           /*<script type="text/javascript">parent.location.href="../logout.do"</script>
            * 这是一句客户端代码，表示定位到父节点
            * 客户端代码需要再java中传递过去
            * */
           response.getWriter().print("<script type=\"text/javascript\">parent.location.href=\"../logout.do\"</script>");

       }

   }

}