zk 获取session，request，servletContext，response

(参考:http://www.dotblogs.com.tw/rockywang/archive/2010/01/13/12995.aspx)

HttpServletRequest request = (HttpServletRequest) Executions.getCurrent().getNativeRequest();
HttpSession session = request.getSession(true);

或

HttpSession session = (HttpSession) Executions.getCurrent().getDesktop().getSession();

ServletContext sc =

(ServletContext) Sessions.getCurrent().getWebApp().getNativeContext();

HttpServletRequest request =

(HttpServletRequest) Executions.getCurrent().getNativeRequest();

HttpServletResponse response = (HttpServletResponse)Executions.getCurrent().getNativeResponse();