chore: adds custom exceptions for EcommerceSystem

Author: mercedes-mathews

lesson_14/exceptions/exceptions_app/src/main/java/com/codedifferently/lesson14/ecommerce/EcommerceSystem.java

@@ -20,6 +20,9 @@ public void addProduct(String productId, String name) {
   public String placeOrder(String productId, int quantity) {
     Product product = products.get(productId);
     String orderId = UUID.randomUUID().toString();
+    if (product == null) {
+      throw new ProductNotFoundException("Product with ID " + productId + " not found");
+    }
     orders.put(orderId, new Order(orderId, product, quantity));
     return orderId;
   }
@@ -30,6 +33,9 @@ public void cancelOrder(String orderId) {
 
   public String checkOrderStatus(String orderId) {
     Order order = orders.get(orderId);
+    if (order == null) {
+      throw new OrderNotFoundException("Order with ID " + orderId + " not found");
+    }
     return "Order ID: "
         + orderId
         + ", Product: "

lesson_14/exceptions/exceptions_app/src/main/java/com/codedifferently/lesson14/ecommerce/OrderNotFoundException.java

@@ -5,4 +5,8 @@
 
 package com.codedifferently.lesson14.ecommerce;
 
-class OrderNotFoundException {}
+public class OrderNotFoundException extends RuntimeException {
+  public OrderNotFoundException(String message) {
+    super(message);
+  }
+}

lesson_14/exceptions/exceptions_app/src/main/java/com/codedifferently/lesson14/ecommerce/ProductNotFoundException.java

@@ -5,4 +5,8 @@
 
 package com.codedifferently.lesson14.ecommerce;
 
-class ProductNotFoundException {}
+class ProductNotFoundException extends RuntimeException {
+  public ProductNotFoundException(String message) {
+    super(message);
+  }
+}