Add interstitial to pdf library - timer

Question

I try to create a book with pdf library i found this library , i created my book everything is ok , i just wanna add interstitial admob and show it every 30 seconds , i tried with handler runnable but it's still show just one time.
mInterstitialAd = new InterstitialAd(this);
mInterstitialAd.setAdUnitId("ca-app-pub-3940256099942544/1033173712");
mInterstitialAd.loadAd(new AdRequest.Builder().build());
handler = new Handler();
final Runnable r = new Runnable() {
public void run() {
if (mInterstitialAd.isLoaded()) {
mInterstitialAd.show();
}
handler.postDelayed(this, 1000);
}
};
handler.postDelayed(r, 1000);

Answer 1

You can use ScheduledExecutorService, and schedule a periodic action.
mInterstitialAd.setAdListener(new AdListener() {
public void onAdLoaded() {
// don't show Ad here
}
#Override
public void onAdClosed() {
createRequest(); //load request whenever ad closed by user
}
});
createRequest();
ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleAtFixedRate(new Runnable() {
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
if (mInterstitialAd.isLoaded())
mInterstitialAd.show();
else
createRequest();
}
});
}
}, 30, 30, TimeUnit.SECONDS);
And createRequest() method
public void createRequest(){
AdRequest adRequest = new AdRequest.Builder().build();
mInterstitialAd.loadAd(adRequest);
}