我可以在Spring MVC的Interceptor中使用RedirectAttributes或FlashMap吗？
我有一个拦截器来处理用户会话。 如果user属性不存在，则拦截器将重定向到登录页面。 我想发送带有重定向url的session timeout消息，但我不想在url中显示该消息。 我为RedirectAttributes或FlashMap搜索了很多FlashMap ，但我找不到任何好的解决方案。
public class UserSessionInterceptor extends HandlerInterceptorAdapter { protected final Logger logger = LoggerFactory.getLogger(this.getClass()); @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { User user = (User)request.getSession().getAttribute(CommonConstants.USER_SESSION_KEY); if (user == null) { String msg = String.format("session timeout"); logger.error(msg); // response.sendRedirect("/signin?errorMessage=" + msg); //I don't want to do this.. return false; } return true; } }
signinController片段：
@Controller @SessionAttributes(CommonConstants.KAPTCHA_SESSION_KEY) public class SigninController extends BaseController { @RequestMapping(value = "/signin", method = RequestMethod.GET) public String signinPage() { return "forward:/index.jsp"; } @RequestMapping(value = "/signin", method = RequestMethod.POST) public String signin(UserForm userForm, @ModelAttribute(CommonConstants.KAPTCHA_SESSION_KEY) String captchaExpected, RedirectAttributes redirectAttributes, HttpServletRequest request) { userForm.setCaptchaExpected(captchaExpected); try { loginValidator.validate(userForm); } catch (ValidateFailedException e) { logger.error(e.getMessage(), e); redirectAttributes.addFlashAttribute(ERROR_MESSAGE_KEY, e.getMessage()); return "redirect:/signin"; } User user = userService.getByUsername(userForm.getUsername()); if (user == null || !user.getPassword().equals(DigestUtils.md5Hex(userForm.getPassword()))) { redirectAttributes.addFlashAttribute(ERROR_MESSAGE_KEY, "username or password is invalid"); return "redirect:/signin"; } request.getSession().setAttribute(CommonConstants.USER_SESSION_KEY, user); return "redirect:/dashboard"; } }
index.jsp片段：
welcome ${errorMessage}
非常感谢你！
我刚遇到同样的问题。 我对spring源代码进行了调试，寻找spring mvc与flashmap属性的相同之处，并在会话中提出了相同的flashmap属性。
这是我最后的解决方案：
// create a flashmap FlashMap flashMap = new FlashMap(); // store the message flashMap.put("ERROR_MESSAGE", "this is the message"); // create a flashmapMapManger with `request` FlashMapManager flashMapManager = RequestContextUtils.getFlashMapManager(request); // save the flash map data in session with falshMapManager flashMapManager.saveOutputFlashMap(flashMap, request, response);
- 上面的代码引用了方法
org.springframework.web.servlet.view.RedirectView#renderMergedOutputModel，你可以自己检查一下
希望这会对你有所帮助！
这是在Spring 5.0中执行此操作的另一种方法
public class LoginInterceptor extends HandlerInterceptorAdapter{ @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { String loginUrl = request.getContextPath() + "/login"; if(request.getSession().getAttribute("loggedInUser") == null) { FlashMap outputFlashMap = RequestContextUtils.getOutputFlashMap(request); outputFlashMap.put("loginError", "Please login to continue"); //New utility added in Spring 5 RequestContextUtils.saveOutputFlashMap(loginUrl, request, response); response.sendRedirect(loginUrl); return false; } return true; } }