Android keep trying POST until it goes through

I have a POST message I absolutely have to send on Android in a given circumstance, to the point I would like it to keep trying until it completes. I was under the understanding that setting:

urlConnection.setConnectTimeout(0);

would keep trying the connection until it goes through, but what is actually happening is the try block is failing, and the UnknownHostException is being thrown instead:

 try{
            Log.d(TAG, "sendAlarm: trying");
            URL finalURL = new URL(stringUrl);              
            urlConnection = (HttpsURLConnection)finalURL.openConnection();
            urlConnection.setReadTimeout(10000);
            urlConnection.setConnectTimeout(0);
            urlConnection.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
            urlConnection.setRequestProperty("Accept","application/json");
            urlConnection.setRequestProperty("x-api-key",apiKey);
            urlConnection.setRequestMethod("POST");
            urlConnection.setDoInput(true);
            urlConnection.setDoOutput(true);

            int responseCode = urlConnection.getResponseCode();
            Log.d(TAG, "doInBackground: response code = " + responseCode);

        }catch (MalformedURLException e) {
            e.printStackTrace();
            Log.d(TAG, "doInBackground: error 1 " + e.toString());
        }catch(UnknownHostException e){
            Log.d(TAG, "doInBackground: e: " + e);
            Log.d(TAG, "doInBackground: retrying");
        }          
        
        catch(Exception e){
            Log.d(TAG, "doInBackground: error 2 " + e.toString());
        }

Wondering what the best way to set up the post message on Android is, to keep trying the connection until it goes through, even if the phone is on airplane mode for 5 hours.

from Android keep trying POST until it goes through