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。