在线等，很急，各路大神快来帮帮小弟

多加一层判断

String name = (String) request.getSession().getAttribute("u_name1");
if(StringUtils.isNotBlank(name)){
if(name.equals(u_name)){
return new ModelAndView("redirect:/login.jsp");
}
}
if(userService.login(u_name, u_pwd)){
List<User> list = userService.findAll();
for (User user2 : list) {
if(user2.getU_name().equals(u_name)){
request.getSession().setAttribute("u_name1", user2.getU_name());
break;
}
}
return new ModelAndView("redirect:/book/list");
}
return new ModelAndView("redirect:/login.jsp");
}