code: public void finishJson(final Type type, final Object obj) {
          this.contentType = this.jsonContentType;
          this.output = obj;
          finish(request.getJsonConvert().convertTo(getBodyBufferSupplier(), type, obj));
      }
docs: 将对象以JSON格式输出
  
  @param type 指定的类型
  @param obj  输出对象