I'm trying to implement Android in app purchase remove ads function. Under my class, I put private boolean isAdsDisabled; and under onCreate, I put
if (isAdsDisabled) {
            AdView adView = (AdView) this.findViewById(R.id.adView);
            adView.setVisibility(View.GONE);
        } else {
            AdView adView = (AdView) this.findViewById(R.id.adView);
            AdRequest adRequest = new AdRequest.Builder().build();
            adView.loadAd(adRequest);
        }
This is my OnIabPurchaseFinishedListener
IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener
            = new IabHelper.OnIabPurchaseFinishedListener() {
        public void onIabPurchaseFinished(IabResult result,
                                          Purchase purchase)
        {
            if (result.isFailure()) {
                // Handle error
                return;
            }
            else if (purchase.getSku().equals(ITEM_SKU)) {
                removeAds();
            }
        }
    };
My removeAds()
private void removeAds() {
        AdView adView = (AdView) this.findViewById(R.id.adView);
        adView.setVisibility(View.GONE);
        isAdsDisabled = true;
    }
After successful purchase, I manage to hide the ads. However the problem after I restart my app, the ads reappear. Seem like it can't save the boolean isAdsDisabled = true. How to fix this?
