[4주차] 장바구니 만들기

build.gradle.kts

@@ -19,6 +19,10 @@ dependencies {
     implementation("org.springframework.boot:spring-boot-starter-web")
     implementation("org.springframework.boot:spring-boot-starter-validation")
 
+    //MongoDB
+    implementation("org.mongodb:mongodb-driver-core:5.2.0")
+    implementation("org.mongodb:mongodb-driver-sync:5.2.0")
+
     developmentOnly("org.springframework.boot:spring-boot-devtools")
 
     testImplementation("org.springframework.boot:spring-boot-starter-test")

src/main/java/com/example/demo/Application.java

@@ -1,11 +1,19 @@
 package com.example.demo;
 
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoClients;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
 
 @SpringBootApplication
 public class Application {
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
+    @Bean
+    public MongoClient mongoClient(){
+        String mongoURL = "mongodb://localhost:27017";
+        return MongoClients.create(mongoURL);
+    }
 }

src/main/java/com/example/demo/exceptions/ExceedTotalQuantity.java

@@ -0,0 +1,7 @@
+package com.example.demo.exceptions;
+
+public class ExceedTotalQuantity extends RuntimeException {
+    public ExceedTotalQuantity(String message){
+        super(message);
+    }
+}

src/main/java/com/example/demo/models/Cart.java

@@ -0,0 +1,80 @@
+package com.example.demo.models;
+
+import com.example.demo.exceptions.ExceedTotalQuantity;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+public class Cart {
+
+    private final List<CartItem> cartItems;
+    private int totalQuantity;
+
+    public Cart() {
+        this.cartItems = new ArrayList<>();
+        this.totalQuantity = 0;
+    }
+
+    public void checkTotalQuantity(int quantity) {
+        if (this.totalQuantity + quantity > 20) {
+            throw new ExceedTotalQuantity("장바구니 총 합계는 20을 넘길 수 없습니다.");
+        }
+    }
+
+    public void addCartItem(ProductId productId, int quantity) {
+
+        checkTotalQuantity(quantity);
+
+        Optional<CartItem> existingCartItem = findCartItem(productId);
+        if (existingCartItem.isPresent()) {
+            CartItem cartItem = existingCartItem.get();
+            cartItem.addQuantity(quantity);
+        } else {
+            addNewCartItem(productId, quantity);
+        }
+
+        this.totalQuantity += quantity;
+
+    }
+
+    private void addNewCartItem(ProductId productId, int quantity) {
+        if (productId == null) {
+            throw new IllegalArgumentException("상품 ID는 null일 수 없습니다.");
+        }
+        CartItemId cartItemId = new CartItemId();
+        Product product = new Product(productId);
+        CartItem newCartItem = new CartItem(cartItemId, product, quantity);
+        cartItems.add(newCartItem);
+    }
+
+    private Optional<CartItem> findCartItem(ProductId productId) {
+        return cartItems.stream()
+                .filter(cartItem -> {
+                    Product product = cartItem.getProduct();
+                    return product != null &&
+                            product.productId().equals(productId);
+                })
+                .findFirst();
+    }
+
+    public List<CartItem> getCartList() {
+        return cartItems;
+    }
+
+    public void madeCartZero() {
+        this.totalQuantity = 0;
+        this.cartItems.clear();
+    }
+
+    public int getTotalQuantity() {
+        return totalQuantity;
+    }
+
+    @Override
+    public String toString() {
+        return "Cart{" +
+                "cartItems=" + cartItems +
+                ", totalQuantity=" + totalQuantity +
+                '}';
+    }
+}

src/main/java/com/example/demo/models/CartItem.java

@@ -0,0 +1,64 @@
+package com.example.demo.models;
+
+import java.util.Objects;
+
+public class CartItem {
+
+    private final CartItemId id;
+    private final Product product;
+    private int quantity;
+
+    public CartItem(CartItemId id, Product product, int quantity) {
+        if (id == null) {
+            throw new IllegalArgumentException("id는 null일 수 없습니다");
+        }
+        if (product == null) {
+            throw new IllegalArgumentException("product는 null일 수 없습니다");
+        }
+        if (quantity < 1) {
+            throw new IllegalArgumentException("수량은 1 이상이어야 합니다");
+        }
+        this.id = id;
+        this.product = product;
+        this.quantity = quantity;
+    }
+
+    public void addQuantity(int quantity) {
+        if (quantity < 0) {
+            throw new IllegalArgumentException("추가할 수량은 0 이상이어야 합니다");
+        }
+        this.quantity += quantity;
+    }
+
+    public Product getProduct() {
+        return product;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        CartItem cartItem = (CartItem) o;
+        return id.equals(cartItem.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    @Override
+    public String toString() {
+        return "CartItem{"
+                + "id="
+                + id
+                + ", product="
+                + product
+                + ", quantity="
+                + quantity + "}";
+    }
+}

src/main/java/com/example/demo/models/CartItemId.java

@@ -0,0 +1,9 @@
+package com.example.demo.models;
+
+public record CartItemId(
+       String id
+) {
+    public CartItemId(){
+        this(new GenerateId().id());
+    }
+}

src/main/java/com/example/demo/models/GenerateId.java

@@ -0,0 +1,28 @@
+package com.example.demo.models;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.UUID;
+
+public record GenerateId(
+        String id
+) {
+
+    public GenerateId() {
+        this(new IdGenerator().generateId());
+    }
+}
+
+class IdGenerator {
+
+    public String generateId() {
+        LocalDateTime now = LocalDateTime.now();
+        DateTimeFormatter formatter =
+                DateTimeFormatter.ofPattern("yyyyMMddHHmm");
+        String dateTime = now.format(formatter);
+        String shortUUID = UUID.randomUUID().toString().substring(0, 4);
+
+        return dateTime + shortUUID;
+    }
+}
+

src/main/java/com/example/demo/models/Product.java

@@ -0,0 +1,26 @@
+package com.example.demo.models;
+
+import java.util.Objects;
+
+public record Product (
+        ProductId productId
+){
+
+    @Override
+    public String toString() {
+        return "{" + productId + "}";
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (obj == null || getClass() != obj.getClass()) return false;
+        Product product = (Product) obj;
+        return productId.equals(product.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return productId.hashCode();
+    }
+}

src/main/java/com/example/demo/models/ProductId.java

@@ -0,0 +1,11 @@
+package com.example.demo.models;
+
+public record ProductId(
+        String id
+) {
+
+    public ProductId() {
+        this(new GenerateId().id());
+    }
+
+}

src/test/java/com/example/demo/MongoDbTest.java

@@ -0,0 +1,50 @@
+package com.example.demo;
+
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoClients;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoDatabase;
+import org.bson.Document;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@SpringBootTest
+public class MongoDbTest {
+
+    @Autowired
+    private MongoClient mongoClient;
+
+    @Test
+    public void testMongoClientBean() {
+        // MongoClient 빈이 주입되었는지 확인
+        assertThat(mongoClient).isNotNull();
+    }
+    @Test
+    void readProducts() {
+        // 1. DB 서버 접속 간단확인
+        String mongoDatabase = "demo";
+
+        // 2. 데이터 베이스 선택 -> demo
+        MongoDatabase database = mongoClient.getDatabase(mongoDatabase);
+
+        // 3. collection에서 목록 열기 -> products
+        MongoCollection<Document> collection =
+                database.getCollection("products");
+
+        List<Document> documents = new ArrayList<>();
+        collection.find().into(documents);
+
+        documents.forEach(document -> {
+            System.out.println(document.getString("name"));
+            System.out.println(document.getInteger("price"));
+        });
+    }
+
+
+}

src/test/java/com/example/demo/models/CartItemIdTest.java

@@ -0,0 +1,14 @@
+package com.example.demo.models;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class CartItemIdTest {
+    @Test
+    void createCartItemId(){
+        CartItemId id = new CartItemId();
+        System.out.println("Generated ID: " + id.id());
+        assertNotNull(id.id(), "ID should not be null");
+    }
+}

src/test/java/com/example/demo/models/CartItemTest.java

@@ -0,0 +1,47 @@
+package com.example.demo.models;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.ArrayList;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class CartItemTest {
+
+    private CartItem cartItem;
+    private CartItemId cartItemId;
+    private Product product;
+    private ProductId productId;
+    private ArrayList<Product> products;
+
+    @BeforeEach
+    void setUp() {
+        productId = new ProductId();
+        product = new Product(productId);
+
+        cartItemId = new CartItemId();
+        cartItem = new CartItem(cartItemId, product, 1);
+    }
+
+    @Test
+    void addQuantity() {
+        cartItem.addQuantity(1);
+        assertEquals(2, cartItem.getQuantity());
+    }
+    @Test
+    void addQuantity_WhenAddingPositiveNumber_ShouldIncreaseQuantity() {
+        cartItem.addQuantity(1);
+        assertEquals(2, cartItem.getQuantity());
+    }
+
+    @Test
+    void addQuantity_WhenAddingNegativeNumber_ShouldThrowException() {
+        assertThrows(IllegalArgumentException.class, () -> cartItem.addQuantity(-1));
+    }
+
+    @Test
+    void addQuantity_WhenAddingZero_ShouldNotChangeQuantity() {
+        cartItem.addQuantity(0);
+        assertEquals(1, cartItem.getQuantity());
+    }
+}