Ajax Session失效跳转登录页面的方法


            在Struts应用中，我们发出的请求都会经过 相应的拦截器进行相关处理，一般都会有一个用户登录拦截（Session失效拦截）；一般请求的话，如果Session失效时，我们会跳到登录页面，可是如果我们采用AJAX请求时，将会返回登录页面的HTML代码，这肯定不是我们想要的，那么我们如何解决呢？请看以下步骤：

一、建立拦截器





package com.xxx.planeap.interceptor;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.ActionSupport;

import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

import com.xxx.common.contants.ConstantsKey;

import com.xxx.common.contants.SessionKey;

import com.xxx.planeap.domain.User;

import com.xxx.planeap.security.SecurityContextUtil;

/**

* 

* @author Goma OMA1989@YEAH.NET

* @version v1.0

* @since 2012-05-31

* 

*/

public class SecurityInterceptor extends AbstractInterceptor {

private static final long serialVersionUID = 1L;

private Logger logger = Logger.getLogger(SecurityInterceptor.class);

@Override

public String intercept(ActionInvocation invocation) throws Exception {

// TODO Auto-generated method stub

String className = invocation.getAction().getClass().getName();

String action = className.substring(className.lastIndexOf(".")+1,className.length());

String actionName = invocation.getProxy().getActionName();

String result;

HttpServletRequest request = ServletActionContext.getRequest();

HttpServletResponse response = ServletActionContext.getResponse();

String type = request.getHeader("X-Requested-With");

User user = (User) ActionContext.getContext().getSession().get(SessionKey.CURRENT_USER);

if (user == null) {

logger.debug("SECURITY CHECKED: NEED TO LOGIN");

if ("XMLHttpRequest".equalsIgnoreCase(type)) {// AJAX REQUEST PROCESS

response.setHeader("sessionstatus", ConstantsKey.MSG_TIME_OUT);

result = null;

} else {// NORMAL REQUEST PROCESS

result = ActionSupport.LOGIN;

}

} else {

logger.debug("SECURITY CHECKED: USER HAS LOGINED");

SecurityContextUtil.setCurrentUser(user);

boolean hanPerm = SecurityContextUtil.hasPerm(action, actionName);

logger.debug("SECURITY CHECKED: PERMISSION---"+action+"."+actionName+"="+hanPerm);

result = invocation.invoke();

}

return result;

}

}



二、定义全局AJAX请求结束处理方法





//全局的AJAX访问，处理AJAX清求时SESSION超时

$.ajaxSetup({

contentType:"application/x-www-form-urlencoded;charset=utf-8",

complete:function(XMLHttpRequest,textStatus){

//通过XMLHttpRequest取得响应头，sessionstatus 

var sessionstatus=XMLHttpRequest.getResponseHeader("sessionstatus"); 

if(sessionstatus=="timeout"){

//这里怎么处理在你，这里跳转的登录页面

window.location.replace(PlanEap.getActionURI("login"));

}

}

});



也就是ajax发送请求时如果拦截返回一个表示就跳转，否则执行正常操作。