How to send Json array to PHP using Volley RequestQueue

Question

I am trying to send parameters from Android to PHP for my project.

Here's how I send the parameters. Please note that I haven't included the json array on the list of CartRequest yet since I am not sure on how to do it. Please also note that I am not sure if my GSON conversion of ArrayList to Jason Array is working. The reason I wanted to know how to send it to PHP is so that I can check if GSON conversion is actually working

public void sendData(){
        String total_amount = cartTotal.getText().toString();
        String user_id = "28";
        calender = Calendar.getInstance();
        dateformat = new SimpleDateFormat("yyyy-MM-dd");
        timeformat = new SimpleDateFormat("HH:mm:ss");
        date = dateformat.format(calender.getTime());
        time = timeformat.format(calender.getTime());

        listProducts = ShoppingCartHelper.getCartList();

        /** Gson gson = new GsonBuilder().create();
         JsonArray cartitems = gson.toJsonTree(listProducts).getAsJsonArray(); **/

/** UPDATE: Changed GSON to for loop**/

        JSONObject obj = new JSONObject();
        JSONArray cartitems = new JSONArray();
        for (int i=0; i < listProducts.size(); i++) {
          try {
            obj.put("id", id);
            obj.put("quantity",quantity);
            cartitems.put(obj);
        } catch (JSONException e) {
            throw new RuntimeException(e);
        }
    }

        CartRequest cartRequest = new CartRequest(total_amount, user_id, date, time);
        RequestQueue queue = Volley.newRequestQueue(ShoppingCartActivity.this);
        queue.add(cartRequest);
    }

I want to include the Json array cartitems on my cartRequest and queue it. I will only need the id and quantity from the Json array cartitems

Here's my CartRequest code:

public class CartRequest extends StringRequest {
    private static final String REQUEST_URL = "MY_URL";
    private Map<String, String> params;

    public CartRequest(String total_amount, String user_id, String date, String time){
        super(Request.Method.POST, REQUEST_URL, null, null);
        params = new HashMap<>();
        params.put("total_amount", total_amount);
        params.put("user_id", user_id);
        params.put("date", date);
        params.put("time", time);
    }

    @Override
    public Map<String, String> getParams() {
        return params;
    }
}

I will appreciate any help. Thanks in advance!

UPDATE: getting an error after I added the loop.

wrong 2nd argument type. Found: 'org.json.JSONARRAY', required: 'java.lang.String'

Answer 1

you have to make cartItems JSONArray JSONArray cartItems = new JSONArray(); run a loop to add items from your listProducts into cartItems with id and quantity as jsonobjects for each array item.

public CartRequest(String total_amount, String user_id, String date, String time, JSONArray cartItems){
    super(Request.Method.POST, REQUEST_URL, null, null);
    params = new HashMap<>();
    params.put("total_amount", total_amount);
    params.put("user_id", user_id);
    params.put("date", date);
    params.put("time", time);
    params.put("cartitems", cartItems);
}

Answer 2

//JsonArray request

void jsonArrayRequest(){

 String url = "your_url_here";
 RequestQueue queue = Volley.newRequestQueue(this);
 JsonArrayRequest req = new JsonArrayRequest(url,
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    Log.d(TAG, response.toString());        
                    pDialog.hide();             
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    VolleyLog.d(TAG, "Error: " + error.getMessage());
                    pDialog.hide();
                }
            });
    queue.addRequest(req);

}

refer http://www.androidhive.info/2014/09/android-json-parsing-using-volley/ http://www.androidhive.info/2014/05/android-working-with-volley-library-1/