JavaWeb はセッションと Cookie を使用してログイン認証コード例の共有を実装します

public class LoginInterceptor implements HandlerInterceptor { @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object obj, Exception err) throws Exception { } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object obj, ModelAndView mav) throws Exception { } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object obj) throws Exception { //获取session里的登录状态值 String str = (String) request.getSession().getAttribute("isLogin"); //如果登录状态不为空则返回true，返回true则会执行相应controller的方法 if(str!=null){ return true; } //如果登录状态为空则重定向到登录页面，并返回false，不执行原来controller的方法 response.sendRedirect("/backend/loginPage"); return false; } }

@Controller @RequestMapping("/backend") public class BackendController { @RequestMapping(value = "/loginPage", method = {RequestMethod.GET}) public String loginPage(HttpServletRequest request,String account, String password){ return "login"; } @RequestMapping(value = "/login", method = {RequestMethod.POST}) public String login(HttpServletRequest request,RedirectAttributes model, String account, String password){ //验证账号密码，如果符合则改变session里的状态，并重定向到主页 if ("jack".equals(account)&&"jack2017".equals(password)){ request.getSession().setAttribute("isLogin","yes"); return "redirect:IndexPage"; }else { //密码错误则重定向回登录页，并返回错误，因为是重定向所要要用到RedirectAttributes model.addFlashAttribute("error","密码错误"); return "redirect:loginPage"; } } //登出，移除登录状态并重定向的登录页 @RequestMapping(value = "/loginOut", method = {RequestMethod.GET}) public String loginOut(HttpServletRequest request) { request.getSession().removeAttribute("isLogin"); return "redirect:loginPage"; } @RequestMapping(value = "/IndexPage", method = {RequestMethod.GET}) public String IndexPage(HttpServletRequest request){ return "Index"; } }

public class LoginInterceptor implements HandlerInterceptor { @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object obj, Exception err) throws Exception { } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object obj, ModelAndView mav) throws Exception { } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object obj) throws Exception { // 获取request的cookie Cookie[] cookies = request.getCookies(); if (null==cookies) { System.out.println("没有cookie=============="); } else { // 遍历cookie如果找到登录状态则返回true执行原来controller的方法 for(Cookie cookie : cookies){ if(cookie.getName().equals("isLogin")){ return true; } } } // 没有找到登录状态则重定向到登录页，返回false，不执行原来controller的方法 response.sendRedirect("/backend/loginPage"); return false; } }

@Controller @RequestMapping("/backend") public class BackendController { @RequestMapping(value = "/loginPage", method = {RequestMethod.GET}) public String loginPage(HttpServletRequest request, String account, String password) { return "login"; } @RequestMapping(value = "/login", method = {RequestMethod.POST}) public String login(HttpServletRequest request, HttpServletResponse response, RedirectAttributes model, String account, String password) { if ("edehou".equals(account) && "aidou2017".equals(password)) { Cookie cookie = new Cookie("isLogin", "yes"); cookie.setMaxAge(30 * 60);// 设置为30min cookie.setPath("/"); response.addCookie(cookie); return "redirect:IndexPage"; } else { model.addFlashAttribute("error", "密码错误"); return "redirect:loginPage"; } } @RequestMapping(value = "/logOut", method = {RequestMethod.GET}) public String loginOut(HttpServletRequest request, HttpServletResponse response) { Cookie[] cookies = request.getCookies(); for (Cookie cookie : cookies) { if (cookie.getName().equals("isLogin")) { cookie.setValue(null); cookie.setMaxAge(0);// 立即销毁cookie cookie.setPath("/"); response.addCookie(cookie); break; } } return "redirect:loginPage"; } @RequestMapping(value = "/IndexPage", method = {RequestMethod.GET}) public String IndexPage(HttpServletRequest request) { return "Index"; } }