使用Servlet实现页面跳转，在本地运行没有问题，在服务器端就不可以

protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {request.setCharacterEncoding("UTF-8");

        response.setCharacterEncoding("UTF-8");

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

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

                  MessageDBcon con=new MessageDBcon();

         

         String sql="select * from manager where name='"+name+"' and  pwd='"+pwd+"'";

          ResultSet rs=con.query(sql);     

         int flag=0;

                            try{          

                if(rs.next()){                   

                        flag=1;//验证成功

                                                HttpSession session=request.getSession();

                                                session.setAttribute("manager", name);

                                                //request.getRequestDispatcher("bg_management.jsp").forward(request, response);

                                                 

                                                JOptionPane.showMessageDialog(null, "登陆成功！");

                                                   request.getRequestDispatcher("background_Main.html").forward(request, response);

                          }

                        else {                                      

                            flag=0;//验证不成功

                                                     

                                                       JOptionPane.showMessageDialog(null, "您输入的管理员用户名或密码错误");

                                                       // request.setAttribute("error","您输入的管理员用户名或密码错误");

                                                         

                                                        request.getRequestDispatcher("index.jsp").forward(request, response);

                        }                                   

                }

            catch (SQLException ex){

                            flag=0;                       

     }

         

           

    }