ParseJsonFileAsync.java

//by ashish
//https://in.linkedin.com/in/ashishmehra610

public class ParseJsonFileAsync extends AsyncTask<Void, Void, String> {

    Activity activity;
    public ParseJsonFileAsync(Activity activity){
        this.activity = activity;
    }

    @Override
    protected String doInBackground(Void... params) {
         String json = null;
        try {
            InputStream stream = activity.getAssets().open("my_json_file.json");//at assets folder
            int size = stream.available();
            byte[] buffer = new byte[size];
            stream.read(buffer);
            stream.close();
            json = new String(buffer, "UTF-8");
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        return json;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        try {
            //parse
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}