struts2 Action中获取request, response对象的方法

struts2 Action中获取request, response对象的方法  

ActionContext ctx = ActionContext.getContext();

  HttpServletRequest request = (HttpServletRequest)ctx.get(ServletActionContext.HTTP_REQUEST);

  HttpServletResponse response = (HttpServletResponse)ctx.get(ServletActionContext.HTTP_RESPONSE);

  //ServletActionContext.APPLICATION;
  //ServletActionContext.SESSION;
  //ServletActionContext.PAGE_CONTEXT;