BAEL-2275: Add OrderItem

ddd/src/main/java/com/baeldung/ddd/layers/DomainLayerApplication.java

@@ -7,7 +7,7 @@ import org.springframework.context.annotation.PropertySource;
 @SpringBootApplication
 @PropertySource(value = { "classpath:ddd-layers.properties" })
 public class DomainLayerApplication {
-    public static void main(String[] args) {
+    public static void main(final String[] args) {
         SpringApplication.run(DomainLayerApplication.class, args);
     }
 }

ddd/src/main/java/com/baeldung/ddd/layers/application/OrderController.java

@@ -9,6 +9,8 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.UUID;
+
 @RestController
 @RequestMapping("/orders")
 public class OrderController {
@@ -33,8 +35,8 @@ public class OrderController {
     }
 
     @DeleteMapping(value = "/{id}/products", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
-    void deleteProduct(@PathVariable final ObjectId id, @RequestParam final String name) {
-        orderService.deleteProduct(id, name);
+    void deleteProduct(@PathVariable final ObjectId id, @RequestParam final UUID productId) {
+        orderService.deleteProduct(id, productId);
     }
 
     @PostMapping("/{id}/complete")

ddd/src/main/java/com/baeldung/ddd/layers/application/request/CreateOrderRequest.java

@@ -10,7 +10,7 @@ public class CreateOrderRequest {
     @NotNull private Product product;
 
     @JsonCreator
-    public CreateOrderRequest(@JsonProperty("product") @NotNull Product product) {
+    public CreateOrderRequest(@JsonProperty("product") @NotNull final Product product) {
         this.product = product;
     }
 

ddd/src/main/java/com/baeldung/ddd/layers/application/response/CreateOrderResponse.java

@@ -5,7 +5,7 @@ import org.bson.types.ObjectId;
 public class CreateOrderResponse {
     private final String id;
 
-    public CreateOrderResponse(String id) {
+    public CreateOrderResponse(final String id) {
         this.id = id;
     }
 

ddd/src/main/java/com/baeldung/ddd/layers/domain/DomainException.java

@@ -0,0 +1,7 @@
+package com.baeldung.ddd.layers.domain;
+
+class DomainException extends RuntimeException {
+    DomainException(final String message) {
+        super(message);
+    }
+}

ddd/src/main/java/com/baeldung/ddd/layers/domain/Order.java

@@ -1,22 +1,22 @@
 package com.baeldung.ddd.layers.domain;
 
-import com.baeldung.ddd.layers.domain.exception.DomainException;
 import org.bson.types.ObjectId;
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.UUID;
 
 public class Order {
     private final ObjectId id;
     private OrderStatus status;
-    private List<Product> products;
+    private List<OrderItem> orderItems;
     private BigDecimal price;
 
     public Order(final ObjectId id, final Product product) {
         this.id = id;
-        this.products = new ArrayList<>(Collections.singletonList(product));
+        this.orderItems = new ArrayList<>(Collections.singletonList(new OrderItem(product)));
         this.status = OrderStatus.CREATED;
         this.price = product.getPrice();
     }
@@ -26,29 +26,30 @@ public class Order {
         this.status = OrderStatus.COMPLETED;
     }
 
-    public void addProduct(final Product product) {
+    public void addOrder(final Product product) {
         validateState();
         validateProduct(product);
-        products.add(product);
+        orderItems.add(new OrderItem(product));
         price = price.add(product.getPrice());
     }
 
-    public void removeProduct(final String name) {
+    public void removeOrder(final UUID id) {
         validateState();
-        final Product product = getProduct(name);
-        products.remove(product);
+        final OrderItem orderItem = getOrderItem(id);
+        orderItems.remove(orderItem);
 
-        price = price.subtract(product.getPrice());
+        price = price.subtract(orderItem.getPrice());
     }
 
-    private Product getProduct(String name) {
-        return products
+    private OrderItem getOrderItem(final UUID id) {
+        return orderItems
           .stream()
-          .filter(product -> product
-            .getName()
-            .equals(name))
+          .filter(orderItem -> orderItem
+            .getProduct()
+            .getId()
+            .equals(id))
           .findFirst()
-          .orElseThrow(() -> new DomainException("Product with " + name + " doesn't exist."));
+          .orElseThrow(() -> new DomainException("Product with " + id + " doesn't exist."));
     }
 
     private void validateState() {
@@ -71,11 +72,11 @@ public class Order {
         return status;
     }
 
-    public List<Product> getProducts() {
-        return Collections.unmodifiableList(products);
-    }
-
     public BigDecimal getPrice() {
         return price;
     }
+
+    public List<OrderItem> getOrderItems() {
+        return orderItems;
+    }
 }

ddd/src/main/java/com/baeldung/ddd/layers/domain/OrderItem.java

@@ -0,0 +1,33 @@
+package com.baeldung.ddd.layers.domain;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+
+public class OrderItem {
+    private final Product product;
+
+    public OrderItem(final Product product) {
+        this.product = product;
+    }
+
+    public BigDecimal getPrice() {
+        return product.getPrice();
+    }
+
+    public Product getProduct() {
+        return product;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        OrderItem orderItem = (OrderItem) o;
+        return Objects.equals(product, orderItem.product);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(product);
+    }
+}

ddd/src/main/java/com/baeldung/ddd/layers/domain/Product.java

@@ -5,13 +5,16 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 
 import java.math.BigDecimal;
 import java.util.Objects;
+import java.util.UUID;
 
 public class Product {
+    private final UUID id;
     private final BigDecimal price;
     private final String name;
 
     @JsonCreator
-    public Product(@JsonProperty("price") final BigDecimal price, @JsonProperty("name") final String name) {
+    public Product(@JsonProperty("id") final UUID id, @JsonProperty("price") final BigDecimal price, @JsonProperty("name") final String name) {
+        this.id = id;
         this.price = price;
         this.name = name;
     }
@@ -24,20 +27,20 @@ public class Product {
         return name;
     }
 
+    public UUID getId() {
+        return id;
+    }
+
     @Override
-    public boolean equals(final Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
-        }
-        final Product product = (Product) o;
-        return Objects.equals(price, product.price) && Objects.equals(name, product.name);
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Product product = (Product) o;
+        return Objects.equals(id, product.id) && Objects.equals(price, product.price) && Objects.equals(name, product.name);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(price, name);
+        return Objects.hash(id, price, name);
     }
 }

ddd/src/main/java/com/baeldung/ddd/layers/domain/exception/DomainException.java

@@ -1,7 +0,0 @@
-package com.baeldung.ddd.layers.domain.exception;
-
-public class DomainException extends RuntimeException {
-    public DomainException(final String message) {
-        super(message);
-    }
-}

ddd/src/main/java/com/baeldung/ddd/layers/domain/service/DomainOrderService.java

@@ -5,11 +5,13 @@ import com.baeldung.ddd.layers.domain.Product;
 import com.baeldung.ddd.layers.domain.repository.OrderRepository;
 import org.bson.types.ObjectId;
 
+import java.util.UUID;
+
 public class DomainOrderService implements OrderService {
 
     private final OrderRepository orderRepository;
 
-    public DomainOrderService(OrderRepository orderRepository) {
+    public DomainOrderService(final OrderRepository orderRepository) {
         this.orderRepository = orderRepository;
     }
 
@@ -22,15 +24,15 @@ public class DomainOrderService implements OrderService {
     }
 
     @Override
-    public void addProduct(ObjectId id, Product product) {
+    public void addProduct(final ObjectId id, final Product product) {
         final Order order = getOrder(id);
-        order.addProduct(product);
+        order.addOrder(product);
 
         orderRepository.save(order);
     }
 
     @Override
-    public void completeOrder(ObjectId id) {
+    public void completeOrder(final ObjectId id) {
         final Order order = getOrder(id);
         order.complete();
 
@@ -38,9 +40,9 @@ public class DomainOrderService implements OrderService {
     }
 
     @Override
-    public void deleteProduct(ObjectId id, String name) {
+    public void deleteProduct(final ObjectId id, final UUID productId) {
         final Order order = getOrder(id);
-        order.removeProduct(name);
+        order.removeOrder(productId);
 
         orderRepository.save(order);
     }

ddd/src/main/java/com/baeldung/ddd/layers/domain/service/OrderService.java

@@ -3,6 +3,8 @@ package com.baeldung.ddd.layers.domain.service;
 import com.baeldung.ddd.layers.domain.Product;
 import org.bson.types.ObjectId;
 
+import java.util.UUID;
+
 public interface OrderService {
     ObjectId createOrder(final Product product);
 
@@ -10,5 +12,5 @@ public interface OrderService {
 
     void completeOrder(ObjectId id);
 
-    void deleteProduct(ObjectId id, String name);
+    void deleteProduct(ObjectId id, UUID productId);
 }

ddd/src/main/java/com/baeldung/ddd/layers/infrastracture/configuration/BeanConfiguration.java

@@ -10,7 +10,7 @@ import org.springframework.context.annotation.Configuration;
 
 @Configuration
 @ComponentScan(basePackageClasses = DomainLayerApplication.class)
-public class DomainConfiguration {
+public class BeanConfiguration {
 
     @Bean
     OrderService orderService(final OrderRepository orderRepository) {

ddd/src/test/java/com/baeldung/ddd/layers/domain/OrderProvider.java

@@ -3,10 +3,11 @@ package com.baeldung.ddd.layers.domain;
 import org.bson.types.ObjectId;
 
 import java.math.BigDecimal;
+import java.util.UUID;
 
 public class OrderProvider {
     public static Order getCreatedOrder() {
-        return new Order(ObjectId.get(), new Product(BigDecimal.TEN, "productName"));
+        return new Order(ObjectId.get(), new Product(UUID.randomUUID(), BigDecimal.TEN, "productName"));
     }
 
     public static Order getCompletedOrder() {

ddd/src/test/java/com/baeldung/ddd/layers/domain/OrderUnitTest.java

@@ -1,13 +1,11 @@
 package com.baeldung.ddd.layers.domain;
 
-import com.baeldung.ddd.layers.domain.exception.DomainException;
-import org.bson.types.ObjectId;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.function.Executable;
 
 import java.math.BigDecimal;
-import java.util.Arrays;
+import java.util.UUID;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -25,22 +23,26 @@ class OrderUnitTest {
     @Test
     void shouldAddProduct_thenUpdatePrice() {
         final Order order = OrderProvider.getCreatedOrder();
-        final int orderOriginalProductSize = order.getProducts().size();
+        final int orderOriginalProductSize = order
+          .getOrderItems()
+          .size();
         final BigDecimal orderOriginalPrice = order.getPrice();
-        final Product productToAdd = new Product(new BigDecimal("20"), "secondProduct");
+        final Product productToAdd = new Product(UUID.randomUUID(), new BigDecimal("20"), "secondProduct");
 
-        order.addProduct(productToAdd);
+        order.addOrder(productToAdd);
 
-        assertEquals(orderOriginalProductSize + 1, order.getProducts().size());
+        assertEquals(orderOriginalProductSize + 1, order
+          .getOrderItems()
+          .size());
         assertEquals(orderOriginalPrice.add(productToAdd.getPrice()), order.getPrice());
     }
 
     @Test
     void shouldAddProduct_thenThrowException() {
         final Order order = OrderProvider.getCompletedOrder();
-        final Product productToAdd = new Product(new BigDecimal("20"), "secondProduct");
+        final Product productToAdd = new Product(UUID.randomUUID(), new BigDecimal("20"), "secondProduct");
 
-        final Executable executable = () -> order.addProduct(productToAdd);
+        final Executable executable = () -> order.addOrder(productToAdd);
 
         Assertions.assertThrows(DomainException.class, executable);
     }
@@ -49,9 +51,15 @@ class OrderUnitTest {
     void shouldRemoveProduct_thenUpdatePrice() {
         final Order order = OrderProvider.getCreatedOrder();
 
-        order.removeProduct(order.getProducts().get(0).getName());
+        order.removeOrder(order
+          .getOrderItems()
+          .get(0)
+          .getProduct()
+          .getId());
 
-        assertEquals(0, order.getProducts().size());
+        assertEquals(0, order
+          .getOrderItems()
+          .size());
         assertEquals(BigDecimal.ZERO, order.getPrice());
     }
 }

ddd/src/test/java/com/baeldung/ddd/layers/domain/service/DomainOrderServiceUnitTest.java

@@ -11,6 +11,7 @@ import org.junit.jupiter.api.function.Executable;
 
 import java.math.BigDecimal;
 import java.util.Optional;
+import java.util.UUID;
 
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -30,7 +31,7 @@ class DomainOrderServiceUnitTest {
 
     @Test
     void shouldCreateOrder_thenSaveIt() {
-        final Product product = new Product(BigDecimal.TEN, "productName");
+        final Product product = new Product(UUID.randomUUID(), BigDecimal.TEN, "productName");
 
         final ObjectId id = tested.createOrder(product);
 
@@ -41,18 +42,18 @@ class DomainOrderServiceUnitTest {
     @Test
     void shouldAddProduct_thenSaveOrder() {
         final Order order = spy(OrderProvider.getCreatedOrder());
-        final Product product = new Product(BigDecimal.TEN, "test");
+        final Product product = new Product(UUID.randomUUID(), BigDecimal.TEN, "test");
         when(orderRepository.findById(order.getId())).thenReturn(Optional.of(order));
 
         tested.addProduct(order.getId(), product);
 
         verify(orderRepository).save(order);
-        verify(order).addProduct(product);
+        verify(order).addOrder(product);
     }
 
     @Test
     void shouldAddProduct_thenThrowException() {
-        final Product product = new Product(BigDecimal.TEN, "test");
+        final Product product = new Product(UUID.randomUUID(), BigDecimal.TEN, "test");
         final ObjectId id = ObjectId.get();
         when(orderRepository.findById(id)).thenReturn(Optional.empty());
 
@@ -76,15 +77,16 @@ class DomainOrderServiceUnitTest {
     @Test
     void shouldDeleteProduct_thenSaveOrder() {
         final Order order = spy(OrderProvider.getCreatedOrder());
-        final String productName = order
-          .getProducts()
+        final UUID productId = order
+          .getOrderItems()
           .get(0)
-          .getName();
+          .getProduct()
+          .getId();
         when(orderRepository.findById(order.getId())).thenReturn(Optional.of(order));
 
-        tested.deleteProduct(order.getId(), productName);
+        tested.deleteProduct(order.getId(), productId);
 
         verify(orderRepository).save(order);
-        verify(order).removeProduct(productName);
+        verify(order).removeOrder(productId);
     }
 }