清除页面数据

   HttpServletResponse response = ServletActionContext.getResponse();
     //清除登陆页面缓存
     response.setHeader("Pragma","No-cache");
     response.setHeader("Cache-Control","no-cache");
     response.setHeader("Cache-Control", "no-store");
     response.setDateHeader("Expires", 0);


     //页面重定位,倒计时。
     String URL = "index.jsp";
     String content=3+";URL="+URL;//3秒后进入主页
     response.setHeader("REFRESH",content);