ajax Session失效如何跳转到登录页面

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

packagecom.xxx.planeap.interceptor;

importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;

importorg.apache.log4j.Logger;
importorg.apache.struts2.ServletActionContext;

importcom.opensymphony.xwork2.ActionContext;
importcom.opensymphony.xwork2.ActionInvocation;
importcom.opensymphony.xwork2.ActionSupport;
importcom.opensymphony.xwork2.interceptor.AbstractInterceptor;
importcom.xxx.common.contants.ConstantsKey;
importcom.xxx.common.contants.SessionKey;
importcom.xxx.planeap.domain.User;
importcom.xxx.planeap.security.SecurityContextUtil;

/**
*
*@[e-mail]
*@versionv1.0
*@since2012-05-31

*
*/
publicclassSecurityInterceptorextendsAbstractInterceptor{
privatestaticfinallongserialVersionUID=1L;
privateLoggerlogger=Logger.getLogger(SecurityInterceptor.class);

@Override
publicStringintercept(ActionInvocationinvocation)throwsException{
//TodoAuto-generatedmethodstub

StringclassName=invocation.getAction().getClass().getName();
Stringaction=className.substring(className.lastIndexOf(".")+1,className.length());
StringactionName=invocation.getProxy().getActionName();

Stringresult;
HttpServletRequestrequest=ServletActionContext.getRequest();
HttpServletResponseresponse=ServletActionContext.getResponse();
Stringtype=request.getHeader("X-Requested-With");
Useruser=(User)ActionContext.getContext().getSession().get(SessionKey.CURRENT_USER);
if(user==null){
logger.debug("SecurityCHECKED:NEEDTOLOGIN");
if("XMLHttpRequest".equalsIgnoreCase(type)){//AJAXREQUESTPROCESS
response.setHeader("sessionstatus",ConstantsKey.MSG_TIME_OUT);
result=null;
}else{//norMALREQUESTPROCESS
result=ActionSupport.LOGIN;
}
}else{
logger.debug("SecurityCHECKED:USERHASLOGINED");
SecurityContextUtil.setCurrentUser(user);
booleanhanPerm=SecurityContextUtil.hasPerm(action,actionName);
logger.debug("SecurityCHECKED:PERMISSION---"+action+"."+actionName+"="+hanPerm);
result=invocation.invoke();
}
returnresult;
}
}

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"));

}

}

});