SpringMVC之拦截器的的配置和使用

拦截器与过滤器的区别：拦截器只能拦截controller的请求，过滤器可以过滤所有请求

（1）实现HandlerInterceptor接口

　　　在执行控制器中的方法之前执行preHandle（）中的方法

 1 package com.eu.weh.web;
 2 
 3 import javax.servlet.http.HttpServletRequest;
 4 import javax.servlet.http.HttpServletResponse;
 5 import javax.servlet.http.HttpSession;
 6 
 7 import org.springframework.web.servlet.HandlerInterceptor;
 8 import org.springframework.web.servlet.ModelAndView;
 9 
10 import com.eu.weh.bean.User;
11 
12 /**
13  * 
14  * @ClassName: LoginInterceptor
15  * @Description: 登录拦截器
16  * @author Administrator
17  * @date 2019年4月29日 上午10:31:25
18  *
19  */
20 public class LoginInterceptor implements HandlerInterceptor {
21 
22     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
23             throws Exception {
24         
25         //判断当前用户是否已经登录
26         HttpSession session = request.getSession();
27         User loginUser = (User) session.getAttribute("dbUser");
28         if (loginUser == null) {
29             String path = session.getServletContext().getContextPath();
30             response.sendRedirect(path+"/login");
31             return false;
32         }else {
33             return true;
34         }
35     }
36 
37     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
38             ModelAndView modelAndView) throws Exception {
39         
40     }
41 
42     public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
43             throws Exception {
44         
45     }
46 
47 }

（2）SpringMVC配置文件

 1 <mvc:interceptors>
 2         <mvc:interceptor>
 3             <mvc:mapping path="/**" />
 4             <mvc:exclude-mapping path="/login" />
 5             <mvc:exclude-mapping path="/doAJAXlogin" />
 6             <mvc:exclude-mapping path="/bootstrap/**" />
 7             <mvc:exclude-mapping path="/css/**" />
 8             <mvc:exclude-mapping path="/fonts/**" />
 9             <mvc:exclude-mapping path="/img/**" />
10             <mvc:exclude-mapping path="/jquery/**" />
11             <mvc:exclude-mapping path="/layer/**" />
12             <mvc:exclude-mapping path="/script/**" />
13             <mvc:exclude-mapping path="/ztree/**" />
14             <bean class="com.eu.weh.web.LoginInterceptor"></bean>
15         </mvc:interceptor>
16     </mvc:interceptors>