GSON. How to convert json object to json array?

You need to iterate all keys of supplyPrice object, and create New JSONArray using that key value then assign new array to supplyPrice key

JSONObject changeSupplyPrice(JSONObject JSONObj){
    try {
        JSONObject supplyPrice =JSONObj.getJSONObject("supplyPrice");
        JSONArray supplyPriceArray = new JSONArray();
        Iterator<?> keys = supplyPrice.keys();

        while( keys.hasNext() ) {
            String key = (String)keys.next();
            Log.e("JSON Array key",key);
            supplyPriceArray.put(new JSONObject("{"+key+":"+supplyPrice.getString(key)+"}"));

        }
        JSONObj.put("supplyPrice", supplyPriceArray);
        return JSONObj;
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return null;
}

then call the function where you want

try {
        JSONObject JSONObj = new JSONObject("{'taxes': [],'name': 'Laboriosam iusto eum','requiresShipping': false,  'taxable': true,  'sku': 'QBA84J18832',  'product': 12, 'supplyPrice': {    'CAD': 78,   'CHF': 54600.78,    'USD': 20735.52  }}");
        JSONObj = changeSupplyPrice(JSONObj);
        Log.e("Return JSON Object",JSONObj.toString());
    } catch (JSONException e) {
        e.printStackTrace();
    }

GSON uses POJO classes to parse JSON into java objects.

Create A java class containing variables with names and datatype same as keys of JSON object. I think the JSON you are getting is not in the right format.

Class SupplyPrice{
 double CAD;
 double CHF;
 double TRY
}

Class SupplyPriceContainer{
 ArrayList<SupplyPrice> supplyPrice;
}

And your JSON should be

 {
    "CAD": 78,
    "CHF": 54600.78,
    "USD": 20735.52
 }



{
    "supplyPrice": [{
        "CAD": 78,
        "CHF": 0,
        "USD": 0
    }, {
        "CAD": 0,
        "CHF": 54600.00,
        "USD": 0
    }, {
        "CAD": 0,
        "CHF": 0,
        "USD": 20735.52
    }]
 }

Then you can Use GSON's `fromJson(String pJson, Class pClassType) to convert to JAVA object

  Gson gson = new Gson()
  ArrayList<SupplyPrice> suplyPrices = gson.fromJson(pJsonString, SupplyPrice.class);

Now you can use the arraylist to get the data.

Hope this part of code to help you:

    String json = "{\"supplyPrice\": {\n" +
            "        \"CAD\": 78,\n" +
            "        \"CHF\": 54600.78,\n" +
            "        \"USD\": 20735.52\n" +
            "      }}";

    Gson gson = new Gson();
    JsonObject jsonObject = gson.fromJson(json, JsonObject.class);
    JsonObject supplyPrice = jsonObject.get("supplyPrice").getAsJsonObject();
    Type type = new TypeToken<HashMap<String, Double>>() {
    }.getType();
    HashMap<String, Double> parsedJson = gson.fromJson(supplyPrice, type);
    JsonArray jsonArray = new JsonArray();
    for(String key : parsedJson.keySet()) {
        JsonObject jo = new JsonObject();
        jo.addProperty("name", key);
        jo.addProperty("value", parsedJson.get(key));
        jsonArray.add(jo);
    }
    JsonObject result = new JsonObject();
    result.add("supplyPrice", jsonArray.getAsJsonArray());