struts2拦截器使用（用户session失效后的统一页面指向） Mr

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
 */
publicclass UserInterceptor implements Interceptor {

    privatestaticfinallong serialVersionUID =5582842221490358379L;

    publicvoid destroy() {

    }

    /**
     * 在服务启动的时候执行
     */
    publicvoid 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
 */

publicclass UserInterceptor implements Interceptor {

    privatestaticfinallong serialVersionUID =5582842221490358379L;

    publicvoid destroy() {

    }

    /**
     * 在服务启动的时候执行
     */
    publicvoid 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);

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>
        <filter-name>struts-cleanup</filter-name>
        <url-pattern>/*</url-pattern>