json - 在 Go 语言中解析 JSON : Attribute without name

Question

我在将 JSON 文件从 API 解析到 Go 时遇到了一些问题，这是我要解析的 JSON:

{"method":"stats.provider.ex",
"result":{
    "addr":"17a212wdrvEXWuipCV5gcfxdALfMdhMoqh",
    "current":[{
        "algo":3, // algorithm number (3 = X11)
        "name":"X11", // algorithm name
        "suffix":"MH", // speed suffix (kH, MH, GH, TH,...)
        "profitability":"0.00045845", // current profitability in BTC/suffix/Day
        "data":[{ // speed object can contain following fields:
              // a (accepted), rt (rejected target), rs (rejected stale),
              // rd (rejected duplicate) and ro (rejected other)
              // if fields are not present, speed is 0
            "a":"23.09", // accepted speed (in MH/s for X11)
            "rs":"0.54", // rejected speed - stale
            },
            "0.0001234" // balance (unpaid)
        ]},
        ... // other algorithms here
    ],
    "past":[{
        "algo":3,
        "data":[
            [4863234, // timestamp; multiply with 300 to get UNIX timestamp
            {"a":"28.6"}, // speed object
            "0" // balance (unpaid)
            ],[4863235,{"a":"27.4"},"0.00000345"],
            ... // next entries with inc. timestamps
        ]},
        ... // other algorithms here
    ],
    "payments":[{
        "amount":"0.00431400",
        "fee":"0.00023000",
        "TXID":"txidhere",
        "time":1453538732, // UNIX timestamp
        "type":0 // payment type (0 for standard NiceHash payment)
    },
    ... // other payments here
    ]
    }
}

您可以在此链接中找到有关 API 的更多信息:https://www.nicehash.com/doc-api

我遇到的问题是数据属性:

    "data":[{ // speed object can contain following fields:
          // a (accepted), rt (rejected target), rs (rejected stale),
          // rd (rejected duplicate) and ro (rejected other)
          // if fields are not present, speed is 0
        "a":"23.09", // accepted speed (in MH/s for X11)
        "rs":"0.54", // rejected speed - stale
        },
        "0.0001234" // balance (unpaid)
    ]},

因为余额(未付)行，因为它没有名称，所以我不知道如何在 go 中执行结构。

Answer 1

似乎这个“数据”对象可以用以下结构类型来描述(假设它的形状与您的示例没有变化):

type Data struct {
    Timestamp *int64
    Speed     *Speed
    Balance   *float64
}

type Speed struct {
    Accepted          *float64 `json:"a,string,omitempty"`
    RejectedTarget    *float64 `json:"rt,string,omitempty"`
    RejectedStale     *float64 `json:"rs,string,omitempty"`
    RejectedDuplicate *float64 `json:"rd,string,omitempty"`
    RejectedOther     *float64 `json:"ro,string,omitempty"`
}

“Speed”结构具有 JSON 标签，因为该对象非常适合默认的 JSON un/marshaler。

但是，“数据”结构应该实现自定义 json.UnmarshalJSON这样它就可以处理具有不同类型的 JSON 数组的奇怪选择，以序列化其字段。请注意，我下面的示例实现使用了 json.RawMessage type通过允许 JSON 解码器确保正确的 JSON 数组语法并分别存储每个元素的字节来简化事情，以便我们可以根据它们各自的类型和形状对它们进行解码:

// Parse valid JSON arrays as "Data" by assuming one of the following shapes:
// 1: [int64, Speed, string(float64)]
// 2: [Speed, string(float64)]
func (d *Data) UnmarshalJSON(bs []byte) error {

    // Ensure that the bytes contains a valid JSON array.
    msgs := []json.RawMessage{}
    err := json.Unmarshal(bs, &msgs)
    if err != nil {
        return err
    }

    // Parse the initial message as "Timestamp" int64, if necessary.
    idx := 0
    if len(msgs) == 3 {
        ts, err := strconv.ParseInt(string(msgs[idx]), 10, 64)
        if err != nil {
            return err
        }
        d.Timestamp = &ts
        idx++
    }

    // Parse the mandatory "Speed" struct per usual.
    d.Speed = &Speed{}
    err = json.Unmarshal(msgs[idx], &d.Speed)
    idx++
    if err != nil {
        return err
    }

    // Parse the mandatory "Balance" item after trimming quotes.
    balance, err := strconv.ParseFloat(string(msgs[idx][1:len(msgs[idx])-1]), 64)
    if err != nil {
        return err
    }
    d.Balance = &balance

    return nil
}

因此，您可以像这样将有效的、格式正确的 JSON 数组解析为“数据”对象:

jsonstr := `[
  [4863234, {"a":"28.6"}, "0" ],
  [{"a":"23.09","rs":"0.54"},"0.0001234"]
]`

datas := []Data{}
err := json.Unmarshal([]byte(jsonstr), &datas)
if err != nil {
    panic(err)
}
// datas[0] = Data{Timestamp:4863234,Speed{Accepted:28.6},Balance:0}
// datas[1] = Data{Speed{Accepted:23.09,RejectedStale:0.54},Balance:0.0001234}

当然，您还需要实现 json.MarshalJSON如果您想将“数据”对象序列化为 JSON。