fixed crash errors

app/src/main/java/com/example/museumworld/cafe_shop/cafe_activity.java

@@ -178,7 +178,10 @@ public class cafe_activity extends AppCompatActivity implements View.OnClickList
             String cafeQuantity = cafeItemList.get(i).getQuantity();
             String cafeName = cafeItemList.get(i).getItem();
             String cafePrice = cafeItemList.get(i).getPrice();
-            if (!cafeQuantity.equals("0")) {
+
+
+            if (!cafeQuantity.equals("0") && !cafeQuantity.equals("")) {
+                Log.d("cafeQuantity", "The q is: " + cafeQuantity);
                 itemQuantityCafe.add(cafeQuantity);
                 itemNameCafe.add(cafeName);
                 itemPriceCafe.add(cafePrice);

app/src/main/java/com/example/museumworld/cafe_shop/shop_activity.java

@@ -182,7 +182,7 @@ public class shop_activity extends AppCompatActivity implements View.OnClickList
             String shopQuantity = shopItemList.get(i).getQuantity();
             String shopItem = shopItemList.get(i).getItem();
             String shopPriceName = shopItemList.get(i).getPrice();
-            if (!shopQuantity.equals("0")) {
+            if (!shopQuantity.equals("0") && !shopQuantity.equals("")) {
                 itemQuantityShop.add(shopQuantity);
                 itemNameShop.add(shopItem);
                 itemPriceShop.add(shopPriceName);

app/src/main/java/com/example/museumworld/checkout/checkout.java

@@ -131,6 +131,7 @@ public class checkout extends AppCompatActivity implements View.OnClickListener
         int totalCafeItems = 0;
         int totalShop = 0;
         for (int i = 0; i < quantity.size(); i++) {
+
             int currentQuantity = Integer.valueOf(quantity.get(i));
             int currentPrice = Integer.valueOf(prices.get(i));