Updated PR base on comments from code review by codemakerai-dev

Author: github-actions[bot]

example/OrderDao.java

@@ -35,11 +35,17 @@ public OrderDao(Session session) {
      */
     public void save(Order order) {
         checkNotNull(order, "Order cannot be null");
-
+        
+        Transaction transaction = null;
         try {
+            transaction = session.beginTransaction();
             session.save(order);
+            transaction.commit();
             logger.info("Order saved successfully");
         } catch (HibernateException e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
             logger.error("Error occurred while saving order", e);
             throw e;
         }

example/PaymentDao.java

@@ -15,7 +15,22 @@ public PaymentDao(Session session) {
      * @throws HibernateException if an error occurs while saving the payment
      */
     public void save(Payment payment) {
-
+        if(payment == null) {
+            throw new IllegalArgumentException("Payment cannot be null");
+        }
+        
+        Transaction transaction = null;
+        try {
+            transaction = session.beginTransaction();
+            session.save(payment);
+            transaction.commit();
+            logger.info("Payment saved successfully");
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            logger.error("Failed to save payment", e);
+        }
     }
 
     /**
@@ -25,6 +40,14 @@ public void save(Payment payment) {
      * @throws HibernateException If an error occurs while updating the payment.
      */
     public void update(Payment payment) {
+        try {
+            Transaction transaction = session.beginTransaction();
+            session.update(payment);
+            transaction.commit();
+            logger.info("Payment updated successfully");
+        } catch (Exception e) {
+            logger.error("Failed to update payment", e);
+        }
     }
 
     /**