struts2+spring和action 如何实现系统的推出功能啊?

各位大侠:
在开发SSH的项目中实现用户退出功能
struts2+spring和action 如何实现系统的推出功能啊?

用session.clear();
实现不了,是什么原因啊

public String execute(){
HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();
HttpSession session = request.getSession();
//注销session
session.removeAttribute("logName");
session.invalidate();
try{
//清除页面缓存
response.setHeader("Pragma","No-cache");

response.setHeader("Cache-Control","no-cache");
response.setHeader("Cache-Control", "no-store");
response.setDateHeader("Expires", 0);
;
response.sendRedirect("/");//这句出错

}catch(Exception e){
e.printStackTrace();
}
return SUCCESS;
}