【Springmvc拦截器】实现登录

淩亂°似流年 2024-03-31 15:46 10阅读 0赞

##  ##

用户要先登录，才能使用功能。现实中的例子，如学校的教务系统，只公开展示登录页面，只有登录成功，才能浏览其他信息。

拦截器可以用来判断该用户是否登录，如果不登录，就进行拦截。

## 代码部分 ##

项目路径

![9ea5d5201a084872b6f8e3c97ae7d4c2.png][]

1、login.jsp

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%@ page isELIgnored="false" %>
>     <html>
>     <head>
>         <title>Title</title>
>         <% pageContext.setAttribute("page",request.getContextPath());%>
>     </head>
>     <body>
>         <form action="${page}/users/login" method="post">
>             username:<input type="text" name="username"/><br>
>             password:<input type="password" name="password"/><br>
>             <input type="submit" value="登录">
>     
>         </form>
>     </body>
>     </html>

2、success.jsp

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%@ page isELIgnored="false" %>
>     <html>
>     <head>
>         <title>SUCCESS</title>
>         <% pageContext.setAttribute("page",request.getContextPath());%>
>         
>         <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
>     </head>
>     <body>
>     ${key}
>     </body>
>     </html>

3、MyTwoInter.java

>     package com.qingruan.servlet;
>     
>     import org.springframework.stereotype.Component;
>     import org.springframework.web.servlet.HandlerInterceptor;
>     import org.springframework.web.servlet.ModelAndView;
>     
>     import javax.servlet.http.HttpServletRequest;
>     import javax.servlet.http.HttpServletResponse;
>     
>     
>     public class MyTwoInter implements HandlerInterceptor {
>     
>         //目标方法运行之前执行
>         @Override
>         public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
>             System.out.println("MyTwoInter...preHandle()");
>             //表示继续执行后续的操作
>             return true;
>         }
>     
>         //目标方法运行之后运行
>         @Override
>         public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
>             System.out.println("MyTwoInter...postHandle()");
>         }
>     
>         //在整个请求完成之后的操作
>         @Override
>         public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
>             System.out.println("MyTwoInter...afterCompletion()");
>         }
>     }

4、UsersController.java

>     package com.qingruan.servlet;
>     
>     import org.springframework.stereotype.Controller;
>     import org.springframework.web.bind.annotation.RequestMapping;
>     
>     import javax.servlet.http.HttpSession;
>     
>     @Contro

[9ea5d5201a084872b6f8e3c97ae7d4c2.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/245b22c2214d43289348afc62f020388.png