拦截器登录验证

拦截器登录验证

1. 配置

2. 拦截器

   public class LoginInterceptor implements HandlerInterceptor {
       public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
           HttpSession session = request.getSession();
           //已登录,放行
           if (session.getAttribute("userLoginInfo") != null) {
               return true;
           }
           //在登陆页面,放行
           if (request.getRequestURI().contains("login")) {
               return true;
           }
           //未登录,转发到登录页面
           request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
           return false;
       }
   }

3. 控制器

   @Controller
   @RequestMapping("/user")
   public class LoginController {
       //主页
       @RequestMapping("/main")
       public String main() {
           return "main";
       }
       //跳转到登陆页面
       @RequestMapping("/login")
       public String login() {
           return "login";
       }
       //登陆后回到主页
       @RequestMapping("/userlogin")
       public String login(HttpSession session, String username, String pwd, Model model) {
           session.setAttribute("userLoginInfo", username);
           model.addAttribute("username", username);
           return "main";
       }
       //注销后回到登陆页面
       @RequestMapping("/logout")
       public String logout(HttpSession session){
           session.removeAttribute("userLoginInfo");
           return "login";
       }
   }

4. 主页

   首页
   ${username}已登录
   
       注销
   

5. 登陆页面

   登陆页面
   
       用户名:
       密码: