使用AJAX接收后端发出的数据

2017-12-05 20-17-48 的屏幕截图.png

前端页面写的内容

//使用ajax输出从后台获取的信息

• input框的内容

账号:姓名:...

servlet代码

2017-12-05 20-39-12 的屏幕截图.png

protected void username(HttpServletRequest request,                 HttpServletResponse response) throws ServletException, IOException {        /*UserBean userBean = new UserBean();*/        List list = (List) request.getSession().getAttribute("info");        UserBean userBean = (UserBean) list.get(0);        int u_id = userBean.getU_id();        UserBean userBean1 = userService.username(u_id);        System.out.println(userBean1);        JSONArray jsonArray = JSONArray.fromObject(userBean1);        response.getWriter().print(jsonArray);    }

• service
  UserService userService = new UserServiceImpl();
  UserBean username(int u_id);
• serviceImpl
  UserDao userDao =new UserDaoImpl();
  @Override
  public UserBean username(int u_id) {
  return userDao.username(u_id);
  }
• dao
  UserBean username(int u_id);

• daoImpl

  

  2017-12-05 20-47-02 的屏幕截图.png

public UserBean username(int u_id){       //在数据库中查询信息       try{           UserBean userBean = new UserBean();           Connection conn = ConnUtil.getConnextion();           String changeSql = "select * from user WHERE u_id = ?";           PreparedStatement pstm = conn.prepareStatement(changeSql);           pstm.setInt(1, u_id);           ResultSet rs = pstm.executeQuery();           if(rs.next()) {              userBean.setU_userid(rs.getString(2));              userBean.setU_username(rs.getString(3));              userBean.setU_password(rs.getString(4));              userBean.setU_sex(rs.getString(5));              userBean.setU_img(rs.getString(6));               return userBean;           }       }catch (Exception e){           System.out.println(e);       }       return null;   }

使用session接收后端发出的数据

登录成功后数据库的信息就就已经存在了session中,只需要在前端显示页面,即引入js接收即可:

如下所示:

<%        List list = (List) request.getSession().getAttribute("info");        UserBean userBean = (UserBean) list.get(0);    %>...用户名: