Spring MVC会话超时拦截器

SpringMVC 拦截器概述：

    SpringMVC 中的Interceptor 拦截请求是通过HandlerInterceptor 来实现的。在SpringMVC 中定义一个Interceptor 非常简单，主要有两种方式，第一种方式是要定义的Interceptor类要实现了Spring 的HandlerInterceptor 接口，或者是这个类继承实现了HandlerInterceptor 接口的类，比如Spring 已经提供的实现了HandlerInterceptor 接口的抽象类HandlerInterceptorAdapter ；第二种方式是实现Spring的WebRequestInterceptor接口，或者是继承实现了WebRequestInterceptor的类。

1.、要使用拦截器，第一步就必须要引入SpringMVC相关的Jar文件，同时还需要引入aopalliance.jar文件；

2、定义拦截器类：SessionTimeOutInterceptor，具体如下：

第一步：配置web.xml

      <!-- 匹配置Session超时时间，单位分钟 -->

      <session-config>

            <session-timeout>10</session-timeout>

      </session-config>

第二步：配置Spring-mvc.xml

           <!-- 定义拦截器 -->

           <mvc:interceptor>

              <!-- 匹配的是url路径， 如果不配置或/**,将拦截所有的Controller -->

              <mvc:mapping path="/**" /> 

              <bean class="com.kedacom.ies.web.interceptor.SessionTimeOutInterceptor"> 

                  <!-- 过滤拦截的url,包括一些静态资源 -->

                  <property name="excludedUrls">

                        <list>

                              <value>/login</value>

                              <value>/logout</value>

                              <value>/loginUser</value>

                              <value>/property/get</value>

                              <value>/js/</value>

                              <value>/css/</value>

                              <value>/files/</value>

                              <value>/images/</value>

                              <value>/map/</value>

                        </list>

                  </property>

            </bean>

          </mvc:interceptor>

第三部：编写SessionTimeOutInterceptor中的拦截方法

package com.kedacom.ies.web.interceptor;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

import com.kedacom.webcommon.domain.User;

import com.kedacom.webcommon.util.session.HttpSessionManager;

/**

 * Session超时过滤器

 *

 * @author HuangHua

 * @Date 2017-12-8下午3:42:19

 */

public class SessionTimeOutInterceptor implements HandlerInterceptor {

      

      private static Logger log = Logger.getLogger(SessionTimeOutInterceptor.class);

      

      /**

       * 过滤拦截的url

       */

      private List<String> excludedUrls;

       /**

        * 在DispatcherServlet完全处理完请求后被调用

        * 当拦截器抛出异常时,依然会从当前拦截器往回执行所的拦截器的afterCompletion()

        */

      @Override

      public void afterCompletion(HttpServletRequest request,

                  HttpServletResponse response, Object handler, Exception exception)

                  throws Exception {

      }

      /**

       * 在业务处理器处理请求执行完成后,生成视图之前执行的动作

       */

      @Override

      public void postHandle(HttpServletRequest request, HttpServletResponse response,

                  Object handler, ModelAndView modelAndView) throws Exception {

      }

      /**

        * 在业务处理器处理请求之前被调用

        * 如果返回false 则退出本拦截器，本拦截器后面的postHandle与afterCompletion不再执行

        */

      @Override

      public boolean preHandle(HttpServletRequest request, HttpServletResponse response,

                  Object handler) throws Exception {

            String requestUri = request.getRequestURI();

            for (String url : excludedUrls) {

                  if (requestUri.contains(url)) {

                        return true;

                  }

            }

            HttpSession session = request.getSession();

            User user = HttpSessionManager.getUser(session);

            if(user == null){

                  log.info("Pedirect to login page");

//                System.out.println("\n-----Session会话超时，请重新登录-----\n");

                  String url = request.getContextPath() + "/login.html";

//                System.out.println("url=" + url);

                  response.sendRedirect(url);

                  return false;

            } else {

//                System.out.println("\n-----允许通过的URL：" + requestUri + "-----\n");

                  return true;

            }

      }

      public List<String> getExcludedUrls() {

            return excludedUrls;

      }

      public void setExcludedUrls(List<String> excludedUrls) {

            this.excludedUrls = excludedUrls;

      }

  

}