CODEWITHSUNDEEP
androidandroid-volley
David
David

Reputation: 7456

Android: Send request to server every x minutes, update UI accordingly

I'm using Volley for Android. I have a ListView in a fragment. If this ListView is empty (only possible if the connection failed/no internet/etc.), I want to send a GET request to the server for the data, then populate the ListView accordingly if it succeeds. If the call failed, I want to call it again in 5 minutes. This goes on until it succeeds.

What is the best way to achieve this? I'm new to Android development. I read about Services, but IDK if that is overkill.

Upvotes: 0

Views: 1403

Answers (2)

Hanelore Ianoseck
Hanelore Ianoseck

Reputation: 614

You could use ScheduledExecutorService to manage and schedule your request. Take a look at:

Upvotes: 2

jDur
jDur

Reputation: 1491

I use to have a layer to define all my calls to services. Lets say ServiceLayer.java for example.

You could define a Handler as a global variable. (You will need to create the ServiceLayer in the MainThread). And then manage the error in the service call making the handler recall the service in 5 minutes. Something like this

public class ServiceLayer {

Handler handler = new Handler();
...

public void callToService(final String parameter,final String moreParameters,final Callback callbackDefinedByYou){

    StringRequest req = new StringRequest(Method.GET, url, new Response.Listener<String>(){
        @Override
        public void onResponse(String s) {
            //Do whatever you need, populate listviews etc
            callbackDefinedByYou.populateListView(s);
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError volleyError) {
            //Manage the error and recall again this service
            callbackDefinedByYou.onError(volleyError);
            handler.postDelayed(new Runnable() {
               public void run(){
                   callToService(parameter, moreParameter, callbackDefinedByYou);
               }

            }, 300000); //5 minutes
        }
    });

    VolleyHelper.addRequestToQueue(req);
}

In this code, everytime service fails a recall is made but, in some cases you should stop doing net calls. For example when you detect there is no internet conexion, and let the user refresh screen

Upvotes: 1

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