code: public static ActionForm loadActionForm(ActionMapping mapping, HttpServletRequest request) {
  		if ("request".equals(mapping.getScope())) {
  			return (ActionForm) request.getAttribute(mapping.getAttribute());
  		} else {
  			HttpSession session = request.getSession();
  			return (ActionForm) session.getAttribute(mapping.getAttribute());
  		}
  	}
docs: 将保存在struts_config.xml定义的attribute中ActionForm取出
  
  @param form
  @param mapping
  @param request