后台管理页面往往需要登录才可以进行操作，这时就需要Seession来记录登录状态
要实现起来也是非常简单，只需要自定义一个HandlerInterceptor就行了
自定义的HandlerInterceptor也只有短短几行代码
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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 //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代码
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@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"; }} |
spring的配置
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<!--省略其他基本配置--><!-- 配置拦截器 --><mvc:interceptors> <!-- 配置登陆拦截器 --> <mvc:interceptor> <!--拦截后台页面的请求--> <mvc:mapping path="/backend/**"/> <!--不拦截登录页和登录的请求--> <mvc:exclude-mapping path="/backend/loginPage"/> <mvc:exclude-mapping path="/backend/login"/> <bean class="com.ima.Interceptor.LoginInterceptor"></bean> </mvc:interceptor></mvc:interceptors> |
一个简单的Session实现登录认证系统就这样完成了，如果想登录状态退出浏览器后仍保留一段时间的可以将Session改为Cookie
一般情况下我们都会使用Cookie
Cookie和Session的方法差不多
使用Cookie的自定义HandlerInterceptor
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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的变化也不大
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@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"; }} |
spring的配置和之前的一模一样
注意
这里只是演示,建议在实际项目中Cookie的键和值要经过特殊处理，否则会引发安全问题
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：http://www.jianshu.com/p/587c56ed9dfa
