struts2拦截器使用（用户session失效后的统一页面指向）
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用户登录之后session我们设置一定的时间失效，失效后页面的转向问题一般都是跳回主页或者是我们自定义的页面
action：
package com.tkbs.web.interceptors;import java.util.Date;import java.util.Map;import javax.annotation.Resource;import com.opensymphony.xwork2.Action;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionInvocation;import com.opensymphony.xwork2.interceptor.Interceptor;import com.tkbs.domain.user.UserAccounts;import com.tkbs.service.user.UserService;/** * 用户拦截器 * author zxg * version 1.0 */public class UserInterceptor implements Interceptor { private static final long serialVersionUID = 5582842221490358379L; public void destroy() { } /** * 在服务启动的时候执行 */ public void init() { } public String intercept(ActionInvocation actionInvocation) throws Exception { System.out.println("<<<教师拦截器初始化..."); ActionContext ctx = ActionContext.getContext(); Map session = ctx.getSession(); // sessionUser 如果session中不存在用户在返回index视图 if (session.get("sessionUser")== null) { return "index"; } String result = actionInvocation.invoke(); return result; }}如果注册页面的请求也包含在拦截器的拦截中加以判断：
package com.tkbs.web.interceptors;import java.util.Date;import java.util.Map;import javax.annotation.Resource;import javax.servlet.http.HttpServletRequest;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.Action;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionInvocation;import com.opensymphony.xwork2.interceptor.Interceptor;import com.tkbs.domain.user.UserAccounts;import com.tkbs.service.user.UserService;/** * 用户拦截器 * author zxg * version 1.0 */public class UserInterceptor implements Interceptor { private static final long serialVersionUID = 5582842221490358379L; public void destroy() { } /** * 在服务启动的时候执行 */ public void init() { } public String intercept(ActionInvocation actionInvocation) throws Exception { System.out.println("<<<教师拦截器初始化..."); ActionContext ctx = ActionContext.getContext(); Map session = ctx.getSession(); // sessionStudent if (session.get("sessionUser")== null) { //判断是不是注册用户，如果是注册用户（包含userRegisterPage）则继续执行，否则跳转到index视图 HttpServletRequest request = (HttpServletRequest)ctx.get(ServletActionContext.HTTP_REQUEST); String uri = request.getRequestURI(); if(uri.indexOf("userRegistPage") == -1) { return "index"; } } String result = actionInvocation.invoke(); return result; }}这里用户的拦截器定义在user包下
User包下拦截器<!-- user 包配置 --> <package name="user" extends="myDefault" namespace="/user"> <interceptors> <interceptor name="userInterceptor" class="com.tkbs.web.interceptors.UserInterceptor"> </interceptor> <interceptor-stack name="userStack"> <interceptor-ref name="userInterceptor"></interceptor-ref> <interceptor-ref name="myDefaultStack"></interceptor-ref> </interceptor-stack> </interceptors> <!-- 默认拦截器，此包下所有的ACTION将都被拦截。如果ACTION再定义了拦截器，则失效 --> <default-interceptor-ref name="userStack"></default-interceptor-ref> <global-results> <!-- 首页--> <result name="index">/index.jsp</result> </global-results> <!-- *_*_* 页面转向${ctp}/page/resource_queryResource_resourceList ...actions.page.resource.queryResource[method=resourceList] ...actions.page.resource.queryResourceDetial[method=resourceDetial] --> <action name="*_*_*" class="{2}Action" method="{3}"> <result name="update" type="redirectAction"> <param name="actionName"> userDiary_userDiary_diaryShow </param> <param name="namespace">/user</param> <param name="parse">true</param> <param name="diaryId">${diaryId}</param> <param name="userId">${userId}</param> </result> <!-- page 与包相应 --> <result name="{3}" type="dispatcher"> /modulePage/{1}/{3}.jsp </result> <!-- json --> <result name="json" type="json" /> <!-- user --> <result name="pwdUpOff" type="redirectAction"> <param name="namespace">/user</param> <param name="actionName"> userUser_user_userIndex </param> <param name="parse">true</param> </result> </action> </package>全局拦截器的定义：
全局拦截器： <!-- default (全局)包配置 --> <package name="myDefault" extends="json-default" namespace="/"> <interceptors> <interceptor name="configInterceptor" class="com.tkbs.web.interceptors.ConfigInterceptor"> </interceptor> <!-- 默认的必须放在最下面！ --> <interceptor-stack name="myDefaultStack"> <interceptor-ref name="configInterceptor"></interceptor-ref> <interceptor-ref name="defaultStack"></interceptor-ref> </interceptor-stack> </interceptors> <!-- 默认拦截器，此包下所有的ACTION将都被拦截。如果ACTION再定义了拦截器，则失效 --> <default-interceptor-ref name="myDefaultStack"></default-interceptor-ref> <global-results> <!-- 首页--> <result name="index">/index.jsp</result> <result name="adminLoginPage"> /moduleAdmin/index/adminLogin.jsp </result> </global-results> <!-- 用户登录 login_adminLogin/userLogin--> <action name="login_*" class="loginAction" method="{1}"> <!-- 前台用户登录 userLogin--> <result name="loginMessage" type="json"></result> <result name="adminLogSuccess" type="redirectAction"> <param name="actionName"> index_indexManage_adminIndex </param> <param name="namespace">/admin</param> </result> <result name="adminLoginIn"> /moduleAdmin/index/adminIndex.jsp </result> <result name="adminLoginPage"> /moduleAdmin/index/adminLogin.jsp </result> </action> <!-- 用户退出登录--> <action name="existLogin_*" class="existLoginAction" method="{1}"> <result name="index">/index.jsp</result> </action> </package>Struts2分别对Request、Session和Application三个对象封装成了三个Map对象，直接使用封装好的Map对象来读取和保存数据。可以通过com.opensymphony.xwork2.ActionContext类来得到这三个对象。ActionContext是Action执行的上下文，保存了很多对象如parameters、request、session、application和locale等。通过ActionContext类获取Map对象的方法为：
ActionContext context=ActionContext.getContext(); --得到Action执行的上下文
Map request=(Map)context.get("request");--得到HttpServletRequest的Map对象?
Map session=context.getSession();--得到HttpSession的Map对象
Map application=context.getApplication();--得到ServletContext的Map对象
HttpServletRequest request = (HttpServletRequest)context.get(ServletActionContext.HTTP_REQUEST);?
HttpServletRequest request = ctx.get(org.apache.struts2.StrutsStatics.HTTP_REQUEST);
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web.xml配置
<!-- session超时定义,单位为分钟 --> <session-config> <session-timeout>20</session-timeout> </session-config> <!-- struts2 --> <filter> <filter-name>struts2</filter-name> <filter-class> <!--org.apache.struts2.dispatcher.FilterDispatcher--> org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter </filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>*.action</url-pattern> </filter-mapping> <!-- 配置struts2的CleanUp的Filter --> <filter> <filter-name>struts-cleanup</filter-name> <filter-class> org.apache.struts2.dispatcher.ActionContextCleanUp </filter-class> </filter> <filter-mapping>