code: public static void putRequestAttribute(HttpServletRequest req, Object re){
          if (null != re){
              if(re instanceof Context){
                  Context context = (Context) re;
                  for(String key : context.keys()){
                      req.setAttribute(key, context.get(key));
                  }
              } else {
                  req.setAttribute(ViewProcessor.DEFAULT_ATTRIBUTE, re);
              }
          }
      }
docs: 保存对象到attribute