JSON Parsing, String to Object, ("Can't convert JSON Object to JSON Array")

Question

I have a JSON String that I'm trying to parse into an array using the following code:

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);
}

but I keep getting the following error:

type org.json.JSONObject cannot be converted to JSONArray

The JSON String looks like this:

"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"
    }
  ]
}

I'm trying to parse the data so that later I can display it in a chart. I'm just trying to parse the JSON into a list so that the data can be split later into smaller lists (id,open,close,high,low) but I'm not sure if there is a better method.

JavaBoy · Accepted Answer · 2020-01-14T15:50:05.810

1

Although i'm missing some data, I can assume what goes wrong:

your JSON is:

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

So your JSON contains an Object that contains an Array of objects. You are trying to create a JSONArray from the root element, which is an Object. JSONArray JSONARR = new JSONArray(holder);

You can solve the problem changing your code navigating from the root to the data property, as follows:

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

edited Jan 14 '20 at 15:50

answered Jan 14 '20 at 15:42

JavaBoy

182
7

1

Thanks, it worked, I was scratching my head on this for so long. – Cruuuiiiiiseer Jan 14 '20 at 17:54

score -1 · Answer 2 · answered Jan 14 '20 at 15:48

You may look at thses links, they also helped me a lot but it's in C#, so you may find same library in java too.

1-Getting 'Cannot cast Newtonsoft.Json.Linq.JObject to Newtonsoft.Json.Linq.JToken' when retrieving items from JSON

2-Read and parse a Json File in C#

JSON Parsing, String to Object, ("Can't convert JSON Object to JSON Array")

2 Answers2