java - JSON 解析，字符串到对象，("Can' t 将 JSON 对象转换为 JSON 数组”)

Question

我有一个 JSON 字符串，我正在尝试使用以下代码将其解析为数组:

try {
    String holder = getJSONString(getApplicationContext());
    JSONArray JSONARR= new JSONArray(holder);

    List<datatemp> dataList = new ArrayList<>();
    for (int i = 0; i < JSONARR.length(); i++) {

        JSONObject jsonObj = JSONARR.getJSONObject(i);
        datatemp data = new datatemp();

        data.ID = Integer.parseInt(jsonObj.getString("id"));
        data.Open = Integer.parseInt(jsonObj.getString("Open"));
        data.Close = Integer.parseInt(jsonObj.getString("Close"));
        data.High = Integer.parseInt(jsonObj.getString("High"));
        data.Low = Integer.parseInt(jsonObj.getString("Low"));

        dataList.add(data);
    }
} catch (JSONException e) {
    Log.e("JSON_ERROR", "unexpected JSON exception", e);
}

但我不断收到以下错误:

type org.json.JSONObject cannot be converted to JSONArray

JSON 字符串如下所示:

"data": [
    {
      "id": "0",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "1",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "2",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "3",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "4",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "5",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "6",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "7",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "8",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "9",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    },
    {
      "id": "10",
      "Open": "1",
      "Close": "1",
      "High": "1",
      "Low": "1"
    }
  ]
}

我正在尝试解析数据，以便稍后可以将其显示在图表中。我只是想将 JSON 解析为一个列表，以便稍后可以将数据拆分为更小的列表(id、open、close、high、low)，但我不确定是否有更好的方法。

Answer 1

虽然我丢失了一些数据，但我可以假设出了什么问题:

您的 JSON 是:

{
  "data" : [
    {  
      "id": "0",
       "Open": "1",
       "Close": "1",
       "High": "1",
       "Low": "1"
    }
  ]
}

因此，您的 JSON 包含一个对象，其中包含对象的数组。您正在尝试从根元素(一个对象)创建 JSONArray。JSONArray JSONARR = new JSONArray(holder);

您可以通过更改从根导航到 data 属性的代码来解决问题，如下所示:

JSONObject jsonObj = new JSONObject(holder);
JSONArray JSONARR = jsonObj.getJSONArray("data");