package com.interceptor;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

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.AbstractInterceptor;

public class AuthorityInterceptor extends AbstractInterceptor{

    /**

     *

     */

    private static final long serialVersionUID = 1L;

    @Override

    /* session过期及操作的权限验证拦截器 */

    public String intercept(ActionInvocation invocation) throws Exception {

        // TODO Auto-generated method stub

        // 取得请求相关的ActionContext实例

        ActionContext context=invocation.getInvocationContext();

        Map session=context.getSession();

        String employ=(String)session.get("employ");

        if(!ServletActionContext.getRequest().isRequestedSessionIdValid()){

            // session 过期

             //return Action.LOGIN;

            //对ajax请求的拦截

            return isAjax();

        }else if (employ==null) {

            //没有登陆，将服务器提示设置成一个HttpServletRequest属性

            context.put("tip","您还没有登录，请登陆系统");

            return isAjax();           

        }else {

            return invocation.invoke();

        }

    }// end function

    private String isAjax() {

        HttpServletRequest request = ServletActionContext.getRequest();

        HttpServletResponse response = ServletActionContext.getResponse();

        response.setCharacterEncoding("text/html;charset=utf-8");

        response.setContentType("text/html;charset=utf-8");

        PrintWriter pw = null;

        try {

            pw = response.getWriter();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        String flag = "";

        if (request.getHeader("X-Requested-With") != null

        && request.getHeader("X-Requested-With").equalsIgnoreCase(

        "XMLHttpRequest")) {  

            flag = "sessionfalse";

            pw.write(flag);

            return null;

         }else{

           return Action.LOGIN;

        }

    }

}