[Feat] Product API 개발

src/main/java/com/kakaoteck/golagola/domain/buyer/entity/Buyer.java

@@ -2,6 +2,7 @@
 
 import com.kakaoteck.golagola.domain.buyer.dto.BuyerRequest;
 import com.kakaoteck.golagola.domain.cart.entity.Cart;
+import com.kakaoteck.golagola.domain.cart.entity.CartProduct;
 import com.kakaoteck.golagola.domain.order.entity.Order;
 import com.kakaoteck.golagola.domain.product.entity.Product;
 import com.kakaoteck.golagola.domain.review.entity.Review;
@@ -25,8 +26,8 @@
 @Entity
 @NoArgsConstructor
 @AllArgsConstructor
-@Builder
 @Getter
+@Builder
 @Table(name = "buyer_table")
 public class Buyer extends BaseEntity implements UserDetails {
 
@@ -63,7 +64,7 @@ public class Buyer extends BaseEntity implements UserDetails {
     @Column(nullable = false)
     private LocalDate registerDate;
 
-    @OneToOne(mappedBy = "buyer", cascade = CascadeType.ALL)
+    @OneToOne(mappedBy = "buyer", cascade = CascadeType.ALL, orphanRemoval = true)
     private Cart cart;
 
     @OneToMany(mappedBy = "buyer", cascade = CascadeType.ALL)
@@ -114,28 +115,36 @@ public void updateProfile(BuyerRequest.MyPagePutDto request) {
     }
 
     public void assignCart(Cart cart) {
-        if (cart != null) {
-            this.cart = cart;
+        this.cart = cart;
+        if (cart.getBuyer() != this) {
             cart.assignBuyer(this);
         }
     }
 
-    public void addProductToCart(Product product) {
+    // Cart를 자동으로 초기화
+    @PrePersist
+    public void initializeCart() {
         if (this.cart == null) {
-            this.cart = new Cart(); // 새로운 Cart 객체 생성
-            this.cart.assignBuyer(this); // Cart와 Buyer 간의 양방향 연관관계 설정
+            Cart newCart = new Cart();
+            newCart.assignBuyer(this);
+            this.cart = newCart;
         }
-        this.cart.getProductList().add(product);
     }
 
     public Cart getOrCreateCart() {
         if (this.cart == null) {
-            this.cart = new Cart(); // 새로운 Cart 객체 생성
-            this.cart.assignBuyer(this); // Cart와 Buyer 간의 양방향 연관관계 설정
+            Cart newCart = new Cart();
+            newCart.assignBuyer(this);
+            this.cart = newCart;
         }
         return this.cart;
     }
 
+    public void addProductToCart(Product product) {
+        Cart cart = this.getOrCreateCart();
+        cart.addProduct(product);
+    }
+
     public static Buyer from(Long buyerId, String nickname, String realName, Gender gender, String email, String password,
                              String address, String phoneNum, Role role, LocalDate registerDate) {
         return Buyer.builder()
@@ -152,4 +161,3 @@ public static Buyer from(Long buyerId, String nickname, String realName, Gender
                 .build();
     }
 }
-

src/main/java/com/kakaoteck/golagola/domain/cart/dto/CartResponse.java

@@ -1,13 +1,13 @@
 package com.kakaoteck.golagola.domain.cart.dto;
 
+import com.kakaoteck.golagola.domain.product.dto.ProductResponse;
 import com.kakaoteck.golagola.domain.product.entity.Product;
 import lombok.Builder;
 
 import java.util.List;
 
 @Builder
 public record CartResponse(
-        List<Product> productList
+        List<ProductResponse.ProductDto> productList
 ) {
-
 }

src/main/java/com/kakaoteck/golagola/domain/cart/entity/Cart.java

@@ -8,6 +8,7 @@
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Entity
@@ -22,18 +23,24 @@ public class Cart {
     @JoinColumn(name = "buyer_id")
     private Buyer buyer;
 
-    @OneToMany(mappedBy = "cart", cascade = CascadeType.ALL)
-    private List<Product> productList;
+    @OneToMany(mappedBy = "cart", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
+    private List<CartProduct> cartProducts = new ArrayList<>();
 
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long cartId;
 
     public void assignBuyer(Buyer buyer) {
-        if (buyer != null) {
-            this.buyer = buyer;
+        this.buyer = buyer;
+        if (buyer.getCart() != this) {
             buyer.assignCart(this);
         }
     }
 
+    public void addProduct(Product product) {
+        CartProduct cartProduct = new CartProduct();
+        cartProduct.assignCart(this);
+        cartProduct.assignProduct(product);
+        this.cartProducts.add(cartProduct);
+    }
 }

src/main/java/com/kakaoteck/golagola/domain/cart/entity/CartProduct.java

@@ -0,0 +1,43 @@
+package com.kakaoteck.golagola.domain.cart.entity;
+
+import com.kakaoteck.golagola.domain.product.entity.Product;
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@NoArgsConstructor
+@AllArgsConstructor
+@Getter
+@Builder
+@Table(name = "cart_product_table")
+public class CartProduct {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "cart_id")
+    private Cart cart;
+
+    @ManyToOne(fetch = FetchType.EAGER)
+    @JoinColumn(name = "product_id")
+    private Product product;
+
+    public void assignCart(Cart cart) {
+        this.cart = cart;
+        if (!cart.getCartProducts().contains(this)) {
+            cart.getCartProducts().add(this);
+        }
+    }
+
+    public void assignProduct(Product product) {
+        this.product = product;
+        if (!product.getCartProducts().contains(this)) {
+            product.getCartProducts().add(this);
+        }
+    }
+}

src/main/java/com/kakaoteck/golagola/domain/cart/repository/CartProductRepository.java

@@ -0,0 +1,10 @@
+package com.kakaoteck.golagola.domain.cart.repository;
+
+import com.kakaoteck.golagola.domain.cart.entity.Cart;
+import com.kakaoteck.golagola.domain.cart.entity.CartProduct;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface CartProductRepository extends JpaRepository<CartProduct, Long> {
+}

src/main/java/com/kakaoteck/golagola/domain/cart/service/CartService.java

@@ -1,21 +1,23 @@
 package com.kakaoteck.golagola.domain.cart.service;
 
-import com.kakaoteck.golagola.domain.buyer.dto.BuyerResponse;
 import com.kakaoteck.golagola.domain.buyer.entity.Buyer;
-import com.kakaoteck.golagola.domain.cart.dto.CartRequest;
 import com.kakaoteck.golagola.domain.cart.dto.CartResponse;
+import com.kakaoteck.golagola.domain.cart.entity.Cart;
+import com.kakaoteck.golagola.domain.cart.entity.CartProduct;
+import com.kakaoteck.golagola.domain.cart.repository.CartProductRepository;
+import com.kakaoteck.golagola.domain.product.dto.ProductResponse;
 import com.kakaoteck.golagola.domain.product.entity.Product;
 import com.kakaoteck.golagola.domain.product.repository.ProductRepository;
 import com.kakaoteck.golagola.global.common.code.status.ErrorStatus;
 import com.kakaoteck.golagola.global.common.exception.GeneralException;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.hibernate.Hibernate;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
-import java.util.Collections;
 import java.util.List;
-import java.util.Optional;
+import java.util.stream.Collectors;
 
 @Service
 @RequiredArgsConstructor
@@ -24,58 +26,78 @@
 public class CartService {
 
     private final ProductRepository productRepository;
+    private final CartProductRepository cartProductRepository;
 
     public CartResponse getCartProducts(Buyer buyer) {
-        // Cart가 null이 아닌 경우에만 productList를 가져오고, 그렇지 않으면 빈 리스트를 반환
-        List<Product> productList = Collections.emptyList();
-        if (buyer.getCart() != null) {
-            productList = buyer.getCart().getProductList() != null ? buyer.getCart().getProductList() : Collections.emptyList();
-        }
+        Cart cart = buyer.getCart();
+
+        // Lazy 로딩을 명시적으로 초기화
+        Hibernate.initialize(cart.getCartProducts());
+
+        // CartProduct 객체에서 Product를 추출하여 리스트 생성
+        List<ProductResponse.ProductDto> products = cart.getCartProducts().stream()
+                .map(cartProduct -> {
+                    Product product = cartProduct.getProduct();
+                    return ProductResponse.ProductDto.builder()
+                            .productId(product.getProductId())
+                            .productName(product.getProductName())
+                            .productExplanation(product.getProductExplanation())
+                            .productPrice(product.getProductPrice())
+                            .build();
+                })
+                .collect(Collectors.toList());
 
         return CartResponse.builder()
-                .productList(productList)
+                .productList(products)
                 .build();
     }
 
     public CartResponse addCartProduct(Buyer buyer, Long productId) {
         Product product = productRepository.findById(productId)
                 .orElseThrow(() -> new GeneralException(ErrorStatus._NOT_FOUND_PRODUCT));
 
-        // Buyer의 cart에 product를 추가
-        buyer.addProductToCart(product);
+        Cart cart = buyer.getOrCreateCart();
 
-        return CartResponse.builder()
-                .productList(buyer.getCart().getProductList())
+        // 장바구니에 이미 동일한 상품이 있는지 확인
+        boolean productExistsInCart = cart.getCartProducts().stream()
+                .anyMatch(cp -> cp.getProduct().getProductId().equals(productId));
+
+        if (productExistsInCart) {
+            throw new GeneralException(ErrorStatus._PRODUCT_ALREADY_IN_CART);  // 이미 존재한다면 예외를 던집니다.
+        }
+
+        // 장바구니에 상품 추가
+        CartProduct cartProduct = CartProduct.builder()
+                .cart(cart)
+                .product(product)
                 .build();
+
+        cartProductRepository.save(cartProduct);
+
+        return getCartProducts(buyer);
     }
 
     public CartResponse deleteCartProduct(Buyer buyer, Long productId) {
-        if (buyer.getCart() == null || buyer.getCart().getProductList() == null) {
-            throw new GeneralException(ErrorStatus._NOT_FOUND_PRODUCT_IN_CART);
-        }
+        Cart cart = buyer.getCart();
 
-        // Buyer의 cart에서 해당 productId에 해당하는 제품을 찾음
-        List<Product> productList = buyer.getCart().getProductList();
-        Product productToRemove = productList.stream()
-                .filter(product -> product.getProductId().equals(productId))
+        CartProduct cartProduct = cart.getCartProducts().stream()
+                .filter(cp -> cp.getProduct().getProductId().equals(productId))
                 .findFirst()
                 .orElseThrow(() -> new GeneralException(ErrorStatus._NOT_FOUND_PRODUCT_IN_CART));
 
-        // 제품을 장바구니에서 삭제
-        productList.remove(productToRemove);
+        cartProductRepository.delete(cartProduct);
 
-        return CartResponse.builder()
-                .productList(productList)
-                .build();
+        return getCartProducts(buyer);
     }
 
     public String emptyCart(Buyer buyer) {
-        if (buyer.getCart() == null || buyer.getCart().getProductList() == null) {
+        Cart cart = buyer.getCart();
+
+        if (cart.getCartProducts().isEmpty()) {
             throw new GeneralException(ErrorStatus._CART_IS_ALREADY_EMPTY);
         }
 
-        // 장바구니를 비움
-        buyer.getCart().getProductList().clear();
+        cartProductRepository.deleteAll(cart.getCartProducts());
 
         return "장바구니에 있는 모든 제품이 삭제되었습니다.";
     }

src/main/java/com/kakaoteck/golagola/domain/product/controller/ProductController.java

@@ -0,0 +1,51 @@
+package com.kakaoteck.golagola.domain.product.controller;
+
+import com.kakaoteck.golagola.domain.product.dto.ProductRequest;
+import com.kakaoteck.golagola.domain.product.dto.ProductResponse;
+import com.kakaoteck.golagola.domain.product.service.ProductService;
+import com.kakaoteck.golagola.domain.seller.dto.SellerResponse;
+import com.kakaoteck.golagola.domain.seller.entity.Seller;
+import com.kakaoteck.golagola.global.common.ApiResponse;
+import io.swagger.v3.oas.annotations.Operation;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/v1/product")
+@CrossOrigin("*")
+public class ProductController {
+
+    private final ProductService productService;
+
+    @Operation(summary = "상품 등록", description = "상품을 등록합니다. 판매자 전용")
+    @PostMapping()
+    public ApiResponse<String> postProduct(
+            @AuthenticationPrincipal Seller seller,
+            @RequestBody ProductRequest request
+    ) {
+        return ApiResponse.onSuccess(productService.postProduct(seller, request));
+    }
+
+    @Operation(summary = "상품 수정", description = "상품 정보를 수정합니다.")
+    @PutMapping("/{productId}")
+    public ApiResponse<ProductResponse> modifyProduct(
+            @AuthenticationPrincipal Seller seller,
+            @PathVariable Long productId,
+            @RequestBody ProductRequest request
+    ) {
+        return ApiResponse.onSuccess(productService.modifyProduct(seller, productId, request));
+    }
+
+    @Operation(summary = "상품 삭제", description = "상품을 삭제합니다. 판매자 전용")
+    @DeleteMapping("/{productId}")
+    public ApiResponse<String> deleteProduct(
+            @AuthenticationPrincipal Seller seller,
+            @PathVariable Long productId
+    ) {
+        productService.deleteProduct(seller, productId);
+        return ApiResponse.onSuccess("상품이 성공적으로 삭제되었습니다.");
+    }
+
+}

src/main/java/com/kakaoteck/golagola/domain/product/dto/ProductRequest.java

@@ -0,0 +1,19 @@
+package com.kakaoteck.golagola.domain.product.dto;
+
+import com.kakaoteck.golagola.global.common.enums.Category;
+import com.kakaoteck.golagola.global.common.enums.DetailCategory;
+import lombok.Builder;
+
+@Builder
+public record ProductRequest(
+        String productName,
+        String productExplanation,
+        String productImage,
+        Long productPrice,
+        Long productInventory,
+        Category category,
+        DetailCategory detailCategory,
+        Long discount,
+        Long productQuantity
+) {
+}