Android Volley, invalidate cache and make fresh re

Question

I couldn't find an updated answer for this. I'm sending requests with Volley to a web API. It returns JSON. I'm using the cache feature like below, but I would like to make sure that the listview is refreshed every so often (say 30 mins for now). How can I invalidate the cache for this given URL to have my app handle that automatically (without a refresh button). This question was helpful in pointing out the difference between invalidate and remove.

MainActivity.java

Cache cache = AppController.getInstance().getRequestQueue().getCache();
        Entry entry = cache.get(URL_FEED);
        if (entry != null) {
            // fetch the data from cache
            try {
                String data = new String(entry.data, "UTF-8");
                try {
                    parseJsonFeed(new JSONArray(data));
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }

        } else 
        {
            // making fresh volley request and getting json

            JsonArrayRequest getRequest = new JsonArrayRequest(URL_FEED,
                    new Response.Listener<JSONArray>()
                    {
                        @Override public void onResponse(JSONArray response) {
                            VolleyLog.d(TAG, "Response: " + response.toString());
                            if (response != null) {
                                parseJsonFeed(response);
                            }
                            Log.d("Response", response.toString());
                        }
                    },......ErrorListener

Answer 1

To refresh listview,you can use volley's serverDate to get the date for when the response was originally received as

AppController.getInstance().getRequestQueue().getCache().get(url).serverDate

this return datetime in long. And in your code use minutedifference function as

  public static long getMinutesDifference(long timeStart,long timeStop){
            long diff = timeStop - timeStart;
            long diffMinutes = diff / (60 * 1000);

            return  diffMinutes;
        }

and Call this function in your code as

Calendar calendar = Calendar.getInstance();
long serverDate = AppController.getInstance().getRequestQueue().getCache().get(url).serverDate;
if(getMinutesDifference(serverDate, calendar.getTimeInMillis()) >=30){
   AppController.getInstance().getRequestQueue().getCache().invalidate(URL_FEED, true);
}

It will invalidate the cache,if previous url response >=30 minutes.

This (invalidate) allows to keep using this data until a new call is made and the cached response is overridden with the new response.