code: public void finishJson(final JsonConvert convert, final Object obj) {
          this.contentType = this.jsonContentType;
          if (this.recycleListener != null) this.output = obj;
          finish(convert.convertTo(getBodyBufferSupplier(), obj));
      }
docs: 将对象以JSON格式输出
  
  @param convert 指定的JsonConvert
  @param obj     输出对象