How to create a proper Volley Listener for cross class Volley method calling

Question

I aim to call Volley from another class in, a very succinct, modular way ie:

            VolleyListener newListener = new VolleyListener();
            Volle         


        

Answer 1

For your requirement, I suggest you refer to my following solution, hope it's clear and helpful:

First is the interface:

public interface VolleyResponseListener {
    void onError(String message);

    void onResponse(Object response);
}

Then inside your helper class (I name it VolleyUtils class):

public static void makeJsonObjectRequest(Context context, String url, final VolleyResponseListener listener) {
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest
                (url, null, new Response.Listener() {

                @Override
                public void onResponse(JSONObject response) {
                    listener.onResponse(response);
                }
            }, new Response.ErrorListener() {

                @Override
                public void onErrorResponse(VolleyError error) {
                    listener.onError(error.toString());
                }
            }) {

        @Override
        protected Response parseNetworkResponse(NetworkResponse response) {
            try {
                String jsonString = new String(response.data,
                        HttpHeaderParser.parseCharset(response.headers, PROTOCOL_CHARSET));
                return Response.success(new JSONObject(jsonString),
                        HttpHeaderParser.parseCacheHeaders(response));
            } catch (UnsupportedEncodingException e) {
                return Response.error(new ParseError(e));
            } catch (JSONException je) {
                return Response.error(new ParseError(je));
            }
        }
    };

    // Access the RequestQueue through singleton class.
    VolleySingleton.getInstance(context).addToRequestQueue(jsonObjectRequest);
}

Then, inside your Activity classes, you can call like the following:

VolleyUtils.makeJsonObjectRequest(mContext, url, new VolleyResponseListener() {
        @Override
        public void onError(String message) {

        }

        @Override
        public void onResponse(Object response) {

        }
    });

You can refer to the following questions for more information (as I told you yesterday):

Android: How to return async JSONObject from method using Volley?

POST Request Json file passing String and wait for the response Volley

Android/Java: how to delay return in a method