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androidandroid-volleyjsonobjectrequest

JsonObjectRequest Synchronisation?

I have to make several requests to an API for an Android App and I am having the following problem: I have a list of items and I have to make a request for each in order to get some data and show it in the app. When my list's size is 1 (in case I have only one item), the app works perfectly but if I have more I get the data mixed and one item have the value of other and things like that.

I am using JsonObjectRequest and Volley. I use callback interfaces for sending back the request data to the activities. I think it's probably a synchronisation problem but I'm not sure and I'm a bit frustrated. I've tried everything!

  • Request Code:

    JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, urlMarket, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {


            try {
                JSONObject singleResult;
                singleResult = response.getJSONArray("result").getJSONObject(0);
                coin.setHigh(singleResult.getDouble("High"));
                coin.setLow(singleResult.getDouble("Low"));
                coin.setLast(singleResult.getDouble("Last"));
                coin.setVolInBtc(singleResult.getDouble("BaseVolume"));
                coin.setBid(singleResult.getDouble("Bid"));
                coin.setAsk(singleResult.getDouble("Ask"));
                coin.setPrevDay(singleResult.getString("PrevDay"));

                callback.onSuccess(coin);
            } catch (Exception e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            error.printStackTrace();
        }
    });

    requestQueue.add(request);

Any kind of help would be appreciated!!

PD.: if there's a better way for doing that instead of JsonObjectRequest, please tell me!

Solution

  • Consider either of these two options:

    1. Extend JSONObjectRequest that accepts a id/token field which is returned as part of the Success/Error callback.

    2. Use a final field as an identifier before you make an API call. Assuming you are making these calls in a loop, you can then refer to this final field from your anonymous callbacks to identify the specific Stock. For example, you can use the ISIN, database ID or ticker symbol to identify the response.