[6주차] 장바구니 만들기

src/main/java/com/example/demo/application/CartService.java

@@ -1,12 +1,13 @@
 package com.example.demo.application;
 
+import com.example.demo.exception.CartNotFoundException;
+import com.example.demo.exception.ProductNotFoundException;
 import com.example.demo.model.Cart;
 import com.example.demo.model.LineItemId;
 import com.example.demo.model.ProductId;
 import com.example.demo.model.ProductOption;
 import com.example.demo.repository.CartRepository;
 import com.example.demo.repository.ProductRepository;
-import jakarta.servlet.http.HttpSession;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -17,43 +18,31 @@ public class CartService {
     private final CartRepository cartRepository;
     private final ProductRepository productRepository;
 
-    private final HttpSession session;
-
-    public CartService(CartRepository cartRepository, ProductRepository productRepository, HttpSession session) {
+    public CartService(CartRepository cartRepository, ProductRepository productRepository) {
         this.cartRepository = cartRepository;
         this.productRepository = productRepository;
-        this.session = session;
     }
 
-    public void addItemToCart(ProductId productId, ProductOption option, int quantity) {
-        Cart cart = getCart();
+    public void addItemToCart(String userId, ProductId productId, ProductOption option, int quantity) {
+        Cart cart = getCart(userId);
         if (!productRepository.existsById(productId)) {
-            throw new IllegalArgumentException("상품이 존재하지 않습니다.");
+            throw new ProductNotFoundException(productId);
         }
         cart.addProduct(productId, option, quantity);
     }
 
-    public void removeLineItem(LineItemId lineItemId) {
-        Cart cart = getCart();
+    public void removeLineItem(String userId, LineItemId lineItemId) {
+        Cart cart = getCart(userId);
         cart.removeLineItem(lineItemId);
     }
 
-    public void clearCart() {
-        Cart cart = getCart();
+    public void clearCart(String userId) {
+        Cart cart = getCart(userId);
         cart.clearItems();
     }
 
-    public Cart getCart() {
-        Long cartId = (Long) session.getAttribute("CART_ID");
-
-        if (cartId != null) {
-            return cartRepository.findById(cartId)
-                    .orElseThrow(() -> new IllegalArgumentException("장바구니가 존재하지 않습니다."));
-        }
-
-        Cart cart = new Cart();
-        Cart savedCart = cartRepository.save(cart);
-        session.setAttribute("CART_ID", savedCart.getId());
-        return savedCart;
+    public Cart getCart(String userId) {
+        return cartRepository.findByUserId(userId)
+                .orElseThrow(CartNotFoundException::new);
     }
 }

src/main/java/com/example/demo/controllers/CartController.java

@@ -4,29 +4,37 @@
 import com.example.demo.controllers.dto.CartResponseDto;
 import com.example.demo.controllers.dto.LineItemResponseDto;
 import com.example.demo.model.Cart;
+import com.example.demo.util.AuthorizationUtils;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import static com.example.demo.util.AuthorizationUtils.extractUserIdFromAuthorization;
+
 @RestController
 @RequestMapping("/cart")
 public class CartController {
 
+    private final CartService cartService;
+
     public CartController(CartService cartService) {
         this.cartService = cartService;
     }
 
-    private final CartService cartService;
 
     @GetMapping
-    public CartResponseDto getCart() {
+    public ResponseEntity<CartResponseDto> getCart(
+            @RequestHeader(name = "Authorization", required = false)
+            String authorization) {
 
-        Cart cart = cartService.getCart();
+        String userId = extractUserIdFromAuthorization(authorization);
+        Cart cart = cartService.getCart(userId);
 
-        return new CartResponseDto(
+        CartResponseDto responseDto = new CartResponseDto(
                 cart.getTotalQuantity(),
                 cart.getLineItems().stream()
                         .map(lineItem -> new LineItemResponseDto(
@@ -37,12 +45,21 @@ public CartResponseDto getCart() {
                                 )
                         ).toList()
         );
+
+        return new ResponseEntity<>(responseDto, HttpStatus.OK);
     }
 
 
     @DeleteMapping()
-    public ResponseEntity<Void> deleteCart() {
-        cartService.clearCart();
+    public ResponseEntity<Void> deleteCart(
+            @RequestHeader(name = "Authorization", required = false)
+            String authorization) {
+
+        String userId = extractUserIdFromAuthorization(authorization);
+
+        cartService.clearCart(userId);
         return new ResponseEntity<>(HttpStatus.NO_CONTENT);
     }
+
+
 }

src/main/java/com/example/demo/controllers/LineItemController.java

@@ -2,6 +2,8 @@
 
 import com.example.demo.application.CartService;
 import com.example.demo.controllers.dto.LineItemRequestDto;
+import com.example.demo.exception.UnauthorizedException;
+import com.example.demo.model.Cart;
 import com.example.demo.model.LineItemId;
 import com.example.demo.model.ProductId;
 import com.example.demo.model.ProductOption;
@@ -11,10 +13,13 @@
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
 
+import static com.example.demo.util.AuthorizationUtils.extractUserIdFromAuthorization;
+
 
 @RestController
 @RequestMapping("/cart/line-items")
@@ -29,9 +34,13 @@ public LineItemController(CartService cartService) {
     @PostMapping
     @ResponseStatus(HttpStatus.CREATED)
     public void create(
-            @Valid @RequestBody LineItemRequestDto requestDto) {
+            @Valid @RequestBody LineItemRequestDto requestDto,
+            @RequestHeader("Authorization") String authorization) {
+
+        String userId = extractUserIdFromAuthorization(authorization);
 
         cartService.addItemToCart(
+                userId,
                 new ProductId(requestDto.productId()),
                 new ProductOption(requestDto.color(), requestDto.size()),
                 requestDto.quantity());
@@ -40,10 +49,14 @@ public void create(
 
     @DeleteMapping("/{lineItemId}")
     @ResponseStatus(HttpStatus.NO_CONTENT)
-    public void deleteLineItem(@PathVariable String lineItemId) {
+    public void deleteLineItem(
+            @PathVariable String lineItemId,
+            @RequestHeader("Authorization") String authorization) {
+
+        String userId = extractUserIdFromAuthorization(authorization);
 
         cartService.removeLineItem(
+                userId,
                 new LineItemId(lineItemId));
     }
-
 }

src/main/java/com/example/demo/exception/CartNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.demo.exception;
+
+public class CartNotFoundException extends RuntimeException {
+    public CartNotFoundException() {
+        super("장바구니를 찾을 수 없습니다.");
+    }
+}

src/main/java/com/example/demo/exception/CartQuantityLimitException.java

@@ -0,0 +1,7 @@
+package com.example.demo.exception;
+
+public class CartQuantityLimitException extends RuntimeException {
+    public CartQuantityLimitException() {
+        super("장바구니에 담을 수 있는 수량을 초과했습니다.");
+    }
+}

src/main/java/com/example/demo/exception/ErrorResponseDto.java

@@ -0,0 +1,8 @@
+package com.example.demo.exception;
+
+
+public record ErrorResponseDto(
+        String code,
+        String message
+) {
+}

src/main/java/com/example/demo/exception/GlobalExceptionHandler.java

@@ -0,0 +1,40 @@
+package com.example.demo.exception;
+
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(CartNotFoundException.class)
+    public ResponseEntity<ErrorResponseDto> handleCartNotFound(CartNotFoundException e) {
+        ErrorResponseDto responseDto = new ErrorResponseDto("CART_NOT_FOUND", e.getMessage());
+        return new ResponseEntity<>(responseDto, HttpStatus.NOT_FOUND);
+    }
+
+    @ExceptionHandler(ProductNotFoundException.class)
+    public ResponseEntity<ErrorResponseDto> handleProductNotFound(ProductNotFoundException e) {
+        ErrorResponseDto responseDto = new ErrorResponseDto("PRODUCT_NOT_FOUND", e.getMessage());
+        return new ResponseEntity<>(responseDto, HttpStatus.NOT_FOUND);
+    }
+
+    @ExceptionHandler(CartQuantityLimitException.class)
+    public ResponseEntity<ErrorResponseDto> handleCartQuantityLimit(CartQuantityLimitException e) {
+        ErrorResponseDto responseDto = new ErrorResponseDto("CART_QUANTITY_LIMIT", e.getMessage());
+        return ResponseEntity
+                .status(HttpStatus.BAD_REQUEST)
+                .contentType(MediaType.APPLICATION_JSON)
+                .body(responseDto);
+    }
+
+    @ExceptionHandler(UnauthorizedException.class)
+    public ResponseEntity<ErrorResponseDto> handleUnauthorized(UnauthorizedException e) {
+        ErrorResponseDto responseDto = new ErrorResponseDto("UNAUTHORIZED", e.getMessage());
+        return new ResponseEntity<>(responseDto, HttpStatus.UNAUTHORIZED);
+    }
+
+}

src/main/java/com/example/demo/exception/ProductNotFoundException.java

@@ -0,0 +1,9 @@
+package com.example.demo.exception;
+
+import com.example.demo.model.ProductId;
+
+public class ProductNotFoundException extends RuntimeException {
+    public ProductNotFoundException(ProductId productId) {
+        super("상품을 찾을 수 없습니다. ID: " + productId.id());
+    }
+}

src/main/java/com/example/demo/exception/UnauthorizedException.java

@@ -0,0 +1,7 @@
+package com.example.demo.exception;
+
+public class UnauthorizedException extends RuntimeException {
+    public UnauthorizedException() {
+        super("인증이 필요합니다.");
+    }
+}

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

@@ -1,6 +1,8 @@
 package com.example.demo.model;
 
+import com.example.demo.exception.CartQuantityLimitException;
 import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
@@ -20,6 +22,9 @@ public class Cart {
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
+    @Column(nullable = false)
+    private String userId;
+
     @OneToMany(mappedBy = "cart", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<LineItem> lineItems = new ArrayList<>();
 
@@ -28,7 +33,12 @@ public class Cart {
     public Cart() {
     }
 
-    public Cart(List<LineItem> lineItems) {
+    public Cart(String userId) {
+        this.userId = userId;
+    }
+
+    public Cart(String userId, List<LineItem> lineItems) {
+        this.userId = userId;
         this.lineItems = new ArrayList<>(lineItems);
         updateTotalQuantity();
     }
@@ -66,7 +76,7 @@ private void updateTotalQuantity() {
                 .mapToInt(LineItem::getQuantity)
                 .sum();
         if (totalQuantity > 20) {
-            throw new IllegalArgumentException("담을수 있는 수량을 초과했습니다.");
+            throw new CartQuantityLimitException();
         }
     }
 

src/main/java/com/example/demo/model/LineItem.java

@@ -3,13 +3,10 @@
 import jakarta.persistence.Embedded;
 import jakarta.persistence.EmbeddedId;
 import jakarta.persistence.Entity;
-import jakarta.persistence.FetchType;
-import jakarta.persistence.JoinColumn;
-import jakarta.persistence.ManyToOne;
 import jakarta.persistence.Table;
 
 @Entity
-@Table(name="line_items")
+@Table(name = "line_items")
 public class LineItem {
 
     @EmbeddedId

src/main/java/com/example/demo/repository/CartRepository.java

@@ -3,5 +3,8 @@
 import com.example.demo.model.Cart;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+import java.util.Optional;
+
 public interface CartRepository extends JpaRepository<Cart, Long> {
+    Optional<Cart> findByUserId(String userId);
 }

src/main/java/com/example/demo/util/AuthorizationUtils.java

@@ -0,0 +1,17 @@
+package com.example.demo.util;
+
+import com.example.demo.exception.UnauthorizedException;
+
+public class AuthorizationUtils {
+
+    private AuthorizationUtils() {
+    }
+
+    public static String extractUserIdFromAuthorization(String authorization) {
+        if (authorization == null || !authorization.startsWith("Bearer ")) {
+            throw new UnauthorizedException();
+        }
+        return authorization.substring(7);
+    }
+
+}