php - 无法 json_encode() 一个 PHP 对象（RESTful 异常错误对象）

Question

我正在尝试将 RESTful Exception Error 对象转换为字符串以保存并发送电子邮件。

我得到错误json_encode(): type is unsupported, encoded as null。从谷歌搜索，似乎 json_encode 不应该有问题，但它不适用于资源变量。

这是对象的样子：

RESTful\Exceptions\HTTPError Object
(
    [response] => Httpful\Response Object
        (
            [body] => stdClass Object
                (
                    [status] => Bad Request
                    [category_code] => request
                    [additional] => 
                    [status_code] => 400
                    [extras] => stdClass Object
                        (
                            [card_uri] => "None" must be a string URI
                        )

                    [category_type] => request
                    [_uris] => stdClass Object
                        (
                        )

                    [request_id] => XXX
                    [description] => Invalid field [card_uri] - "None" must be a string URI Your request id is XXX.
                )

            [raw_body] ⇒ {
  "status": "Bad Request",
  "category_code": "request",
  "additional": null,
  "status_code": 400,
  "extras": {
    "card_uri": "\"None\" must be a string URI"
  },
  "category_type": "request",
  "_uris": {},
  "request_id": "XXX",
  "description": "Invalid field [card_uri] - \"None\" must be a string URI Your request id is XXX."
}