拦截器登录验证

拦截器登录验证

1. 配置

   <mvc:interceptor>
       <mvc:mapping path="/user/**"/>
       <bean class="cn.pinked.config.LoginInterceptor"/>
   </mvc:interceptor>
   

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

   <h1>首页</h1>
   <span>${username}已登录</span>
   <p>
       <a href="${pageContext.request.contextPath}/user/logout">注销</a>
   </p>
   

5. 登陆页面

   <h1>登陆页面</h1>
   <form action="${pageContext.request.contextPath}/user/userlogin" method="post">
       用户名:<input type="text" name="username">
       密码:<input type="password" name="pwd">
       <input type="submit" value="登录">
   </form>