Installation:

// add the JitPack repository to your build file:

allprojects {
repositories {
  ...
  maven { url 'https://jitpack.io' }
  }
}

// add the dependency:

dependencies {
  implementation 'com.github.congle7997:GoogleIAP:Tag'
}

Consumables:

// purchase:

List<String> listSkuStoreInApp = new ArrayList<>();
listSkuStoreInApp.add("YOUR_KEY_INAPP_FROM_STORE");
BillingInApp billingInApp = new BillingInApp(MainActivity.this, listSkuStoreInApp, new CallBackBilling() {
   @Override
   public void onPurchase() {
       Log.d(TAG, "onPurchase: ");
   }

   @Override
   public void onNotPurchase() {
        Log.d(TAG, "onNotPurchase: ");
   }

   @Override
   public void onNotLogin() {
       Log.d(TAG, "onNotLogged: ");
   }
});
billingInApp.purchase("KEY_INAPP_NEED_PURCHASE");

// check purchase:

List<String> listCheckInApp = new ArrayList<>();
listCheckInApp.add("KEY_NEED_CHECK");
BillingInApp billingInApp = new BillingInApp(MainActivity.this, listCheckInApp);
billingInApp.checkPurchase(listCheckInApp, new CallBackBilling() {
   @Override
   public void onPurchase() {
       Log.d(TAG, "onPurchase: ");
   }

   @Override
   public void onNotPurchase() {
       Log.d(TAG, "onNotPurchase: ");
   }

   @Override
   public void onNotLogin() {
       Log.d(TAG, "onNotLogged: ");
   }
});

Not-consumables:

// purchase:

List<String> listSkuStoreSubs = new ArrayList<>();
listSkuStoreSubs.add("YOUR_KEY_SUBS_FROM_STORE");
BillingSubs billingSubs = new BillingSubs(this, listSkuStoreSubs, new CallBackBilling() {
    @Override
    public void onPurchase() {
      Log.d(TAG, "onPurchase: ");
    }

    @Override
    public void onNotPurchase() {
      Log.d(TAG, "onNotPurchase: ");
    }

    @Override
    public void onNotLogin() {
      Log.d(TAG, "onNotLogin: ");
    }
 });
billingSubs.purchase("KEY_SUBS_NEED_PURCHASE");

// check purchase:

List<String> listCheckSubs = new ArrayList<>();
listCheckSubs.add("KEY_NEED_CHECK");
BillingSubs billingSubs = new BillingSubs(this, listCheckSubs);
billingSubs.checkPurchase(listCheckSubs, new CallBackBilling() {
     @Override
     public void onPurchase() {
         Log.d(TAG, "onPurchase: ");
     }

     @Override
     public void onNotPurchase() {
          Log.d(TAG, "onNotPurchase: ");
     }

     @Override
     public void onNotLogin() {
        Log.d(TAG, "onNotPurchase: ");
    }
 });

If you need support, contact me: [email protected]