[volume - 8] Decoupling with Kafka

apps/commerce-api/build.gradle.kts

@@ -2,6 +2,7 @@ dependencies {
     // add-ons
     implementation(project(":modules:jpa"))
     implementation(project(":modules:redis"))
+    implementation(project(":modules:kafka"))
     implementation(project(":supports:jackson"))
     implementation(project(":supports:logging"))
     implementation(project(":supports:monitoring"))
@@ -11,6 +12,12 @@ dependencies {
     implementation("org.springframework.boot:spring-boot-starter-actuator")
     implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:${project.properties["springDocOpenApiVersion"]}")
 
+    // resilience4j
+    implementation("io.github.resilience4j:resilience4j-spring-boot3")
+
+    // feign
+    implementation("org.springframework.cloud:spring-cloud-starter-openfeign")
+
     // querydsl
     annotationProcessor("com.querydsl:querydsl-apt::jakarta")
     annotationProcessor("jakarta.persistence:jakarta.persistence-api")

apps/commerce-api/src/main/java/com/loopers/CommerceApiApplication.java

@@ -4,9 +4,16 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
+import org.springframework.cloud.openfeign.EnableFeignClients;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
 import java.util.TimeZone;
 
 @ConfigurationPropertiesScan
+@EnableFeignClients
+@EnableScheduling
+@EnableAsync
 @SpringBootApplication
 public class CommerceApiApplication {
 

apps/commerce-api/src/main/java/com/loopers/application/like/LikeFacade.java

@@ -23,12 +23,11 @@ public class LikeFacade {
 
     private final LikeService likeService;
 
-    public void createLike(String userId, Long productId) {
+    public void like(String userId, Long productId) {
         likeService.like(userId, productId);
     }
 
-    public void deleteLike(String userId, Long productId) {
+    public void unlike(String userId, Long productId) {
         likeService.unlike(userId, productId);
     }
 }
-

apps/commerce-api/src/main/java/com/loopers/application/order/CreateOrderCommand.java

@@ -15,5 +15,6 @@
  */
 public record CreateOrderCommand(
         String userId,
-        List<OrderItemCommand> items
+        List<OrderItemCommand> items,
+        OrderPaymentCommand payment
 ) {}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderFacade.java

@@ -3,38 +3,33 @@
 import com.loopers.domain.order.Order;
 import com.loopers.domain.order.OrderItem;
 import com.loopers.domain.order.OrderService;
-import com.loopers.domain.order.OrderStatus;
+import com.loopers.domain.order.event.OrderEvent;
+import com.loopers.domain.order.event.OrderEventPublisher;
+import com.loopers.domain.payment.Payment;
+import com.loopers.domain.payment.PaymentService;
 import com.loopers.domain.point.Point;
 import com.loopers.domain.point.PointService;
 import com.loopers.domain.product.Product;
 import com.loopers.domain.product.ProductService;
 import com.loopers.support.error.CoreException;
 import com.loopers.support.error.ErrorType;
 import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Transactional;
 
-/**
- * packageName : com.loopers.application.order
- * fileName     : OrderFacade
- * author      : byeonsungmun
- * date        : 2025. 11. 13.
- * description :
- * ===========================================
- * DATE         AUTHOR       NOTE
- * -------------------------------------------
- * 2025. 11. 13.     byeonsungmun       최초 생성
- */
-
-@Slf4j
 @Component
 @RequiredArgsConstructor
 public class OrderFacade {
 
     private final OrderService orderService;
     private final ProductService productService;
     private final PointService pointService;
+    private final PaymentService paymentService;
+    private final OrderEventPublisher orderEventPublisher;
+    @Value("${app.callback.base-url}")
+    private String callbackBaseUrl;
+
 
     @Transactional
     public OrderInfo createOrder(CreateOrderCommand command) {
@@ -47,13 +42,10 @@ public OrderInfo createOrder(CreateOrderCommand command) {
 
         for (OrderItemCommand itemCommand : command.items()) {
 
-            //상품가져오고
             Product product = productService.getProduct(itemCommand.productId());
 
-            // 재고감소
             product.decreaseStock(itemCommand.quantity());
 
-            // OrderItem생성
             OrderItem orderItem = OrderItem.create(
                     product.getId(),
                     product.getName(),
@@ -64,7 +56,6 @@ public OrderInfo createOrder(CreateOrderCommand command) {
             orderItem.setOrder(order);
         }
 
-        //총 가격구하고
         long totalAmount = order.getOrderItems().stream()
                 .mapToLong(OrderItem::getAmount)
                 .sum();
@@ -74,10 +65,39 @@ public OrderInfo createOrder(CreateOrderCommand command) {
         Point point = pointService.findPointByUserId(command.userId());
         point.use(totalAmount);
 
-        //저장
         Order saved = orderService.createOrder(order);
-        saved.updateStatus(OrderStatus.COMPLETE);
+
+        OrderPaymentCommand paymentCommand = command.payment();
+        String cardType = paymentCommand.cardType();
+        String orderReference = createOrderReference(saved.getId());
+        String callbackUrl = callbackBaseUrl + "/api/v1/orders/" + orderReference + "/callback";
+
+        Payment payment = Payment.pending(
+                saved.getId(),
+                command.userId(),
+                orderReference,
+                cardType,
+                paymentCommand.cardNo(),
+                saved.getTotalAmount()
+        );
+
+        paymentService.save(payment);
+        orderEventPublisher.publish(
+                OrderEvent.PaymentRequested.of(
+                        saved.getId(),
+                        command.userId(),
+                        orderReference,
+                        cardType,
+                        paymentCommand.cardNo(),
+                        saved.getTotalAmount(),
+                        callbackUrl
+                )
+        );
 
         return OrderInfo.from(saved);
     }
+
+    private String createOrderReference(Long orderId) {
+        return "order-" + orderId;
+    }
 }

apps/commerce-api/src/main/java/com/loopers/application/order/OrderInfo.java

@@ -3,26 +3,13 @@
 import com.loopers.domain.order.Order;
 import com.loopers.domain.order.OrderStatus;
 
-import java.time.LocalDateTime;
 import java.util.List;
 
-/**
- * packageName : com.loopers.application.order
- * fileName     : OrderInfo
- * author      : byeonsungmun
- * date        : 2025. 11. 14.
- * description :
- * ===========================================
- * DATE         AUTHOR       NOTE
- * -------------------------------------------
- * 2025. 11. 14.     byeonsungmun       최초 생성
- */
 public record OrderInfo(
         Long orderId,
         String userId,
         Long totalAmount,
         OrderStatus status,
-        LocalDateTime createdAt,
         List<OrderItemInfo> items
 ) {
     public static OrderInfo from(Order order) {
@@ -35,7 +22,6 @@ public static OrderInfo from(Order order) {
                 order.getUserId(),
                 order.getTotalAmount(),
                 order.getStatus(),
-                order.getCreatedAt(),
                 itemInfos
         );
     }

apps/commerce-api/src/main/java/com/loopers/application/order/OrderPaymentCommand.java

@@ -0,0 +1,6 @@
+package com.loopers.application.order;
+
+public record OrderPaymentCommand(
+        String cardType,
+        String cardNo
+) {}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderPaymentProcessor.java

@@ -0,0 +1,109 @@
+package com.loopers.application.order;
+
+import com.loopers.domain.order.Order;
+import com.loopers.domain.order.OrderItem;
+import com.loopers.domain.order.OrderService;
+import com.loopers.domain.order.OrderStatus;
+import com.loopers.domain.payment.Payment;
+import com.loopers.domain.payment.PaymentService;
+import com.loopers.domain.point.Point;
+import com.loopers.domain.point.PointService;
+import com.loopers.domain.product.Product;
+import com.loopers.domain.product.ProductService;
+import com.loopers.infrastructure.dataplatform.OrderDataPlatformClient;
+import com.loopers.infrastructure.payment.PgPaymentClient;
+import com.loopers.infrastructure.payment.dto.PgPaymentV1Dto;
+import com.loopers.interfaces.api.ApiResponse;
+import com.loopers.support.error.CoreException;
+import com.loopers.support.error.ErrorType;
+import lombok.RequiredArgsConstructor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
+
+@Component
+@RequiredArgsConstructor
+public class OrderPaymentProcessor {
+
+    private static final Logger log = LoggerFactory.getLogger(OrderPaymentProcessor.class);
+
+    private final PaymentService paymentService;
+    private final OrderService orderService;
+    private final ProductService productService;
+    private final PointService pointService;
+    private final PgPaymentClient pgPaymentClient;
+    private final OrderDataPlatformClient orderDataPlatformClient;
+
+    @Transactional
+    public void handlePaymentCallback(String orderReference, PgPaymentV1Dto.TransactionStatus status, String transactionKey, String reason) {
+        Payment payment = paymentService.findByOrderReference(orderReference)
+                .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "결제 정보를 찾을 수 없습니다."));
+
+        if (payment.getTransactionKey() != null && payment.getTransactionKey().equals(transactionKey)) {
+            return;
+        }
+
+        Order order = orderService.findById(payment.getOrderId());
+        applyPaymentResult(order, payment, status, transactionKey, reason);
+    }
+
+    @Transactional
+    public void syncPayment(Long orderId) {
+        Payment payment = paymentService.findByOrderId(orderId)
+                .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "결제 정보를 찾을 수 없습니다."));
+        Order order = orderService.findById(orderId);
+        ApiResponse<PgPaymentV1Dto.OrderResponse> response = pgPaymentClient.getPayments(payment.getUserId(), payment.getOrderReference());
+        PgPaymentV1Dto.OrderResponse data = response != null ? response.data() : null;
+
+        if (data == null || data.transactions() == null || data.transactions().isEmpty()) {
+            log.warn("결제 내역을 찾을 수 없습니다. orderId={}, orderReference={}", orderId, payment.getOrderReference());
+            return;
+        }
+
+        PgPaymentV1Dto.TransactionRecord record = data.transactions().get(data.transactions().size() - 1);
+        applyPaymentResult(order, payment, record.status(), record.transactionKey(), record.reason());
+    }
+
+    @Transactional
+    public void handlePaymentResult(Long orderId, PgPaymentV1Dto.TransactionStatus status, String transactionKey, String reason) {
+        Payment payment = paymentService.findByOrderId(orderId)
+                .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "결제 정보를 찾을 수 없습니다."));
+        Order order = orderService.findById(orderId);
+        applyPaymentResult(order, payment, status, transactionKey, reason);
+    }
+
+    private void applyPaymentResult(
+            Order order,
+            Payment payment,
+            PgPaymentV1Dto.TransactionStatus status,
+            String transactionKey,
+            String reason
+    ) {
+        OrderStatus newStatus = OrderPaymentSupport.mapOrderStatus(status);
+        payment.updateStatus(OrderPaymentSupport.mapPaymentStatus(status), transactionKey, reason);
+        paymentService.save(payment);
+
+        if (newStatus == OrderStatus.COMPLETE) {
+            order.updateStatus(OrderStatus.COMPLETE);
+        } else if (newStatus == OrderStatus.FAIL) {
+            revertOrder(order, payment.getUserId());
+        } else {
+            order.updateStatus(OrderStatus.PENDING);
+        }
+
+        orderDataPlatformClient.send(order, payment);
+    }
+
+    private void revertOrder(Order order, String userId) {
+        for (OrderItem item : order.getOrderItems()) {
+            Product product = productService.getProduct(item.getProductId());
+            product.increaseStock(item.getQuantity());
+        }
+        Point point = pointService.findPointByUserId(userId);
+        if (point != null) {
+            point.refund(order.getTotalAmount());
+        }
+        order.updateStatus(OrderStatus.FAIL);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/order/OrderPaymentSupport.java

@@ -0,0 +1,45 @@
+package com.loopers.application.order;
+
+import com.loopers.domain.order.OrderStatus;
+import com.loopers.domain.payment.PaymentStatus;
+import com.loopers.infrastructure.payment.dto.PgPaymentV1Dto.Response;
+import com.loopers.infrastructure.payment.dto.PgPaymentV1Dto.TransactionStatus;
+import com.loopers.interfaces.api.ApiResponse;
+import com.loopers.support.error.CoreException;
+import com.loopers.support.error.ErrorType;
+
+import static com.loopers.infrastructure.payment.dto.PgPaymentV1Dto.TransactionStatus.SUCCESS;
+
+public final class OrderPaymentSupport {
+
+    private OrderPaymentSupport() {
+    }
+
+    public static OrderStatus mapOrderStatus(TransactionStatus status) {
+        if (status == SUCCESS) {
+            return OrderStatus.COMPLETE;
+        }
+        if (status == TransactionStatus.FAILED) {
+            return OrderStatus.FAIL;
+        }
+        return OrderStatus.PENDING;
+    }
+
+    public static PaymentStatus mapPaymentStatus(TransactionStatus status) {
+        if (status == SUCCESS) {
+            return PaymentStatus.SUCCESS;
+        }
+        if (status == TransactionStatus.FAILED) {
+            return PaymentStatus.FAIL;
+        }
+        return PaymentStatus.PENDING;
+    }
+
+    public static Response requirePgResponse(ApiResponse<Response> response) {
+        Response data = response != null ? response.data() : null;
+        if (data == null) {
+            throw new CoreException(ErrorType.INTERNAL_ERROR, "PG 응답을 확인할 수 없습니다.");
+        }
+        return data;
+    }
+}

apps/commerce-api/src/main/java/com/loopers/application/user/UserFacade.java

@@ -1,5 +1,6 @@
 package com.loopers.application.user;
 
+import com.loopers.domain.point.PointService;
 import com.loopers.domain.user.User;
 import com.loopers.domain.user.UserService;
 import com.loopers.support.error.CoreException;
@@ -11,9 +12,11 @@
 @Component
 public class UserFacade {
     private final UserService userService;
+    private final PointService pointService;
 
     public UserInfo register(String userId, String email, String birth, String gender) {
         User user = userService.register(userId, email, birth, gender);
+        pointService.initPoint(user.getUserId());
         return UserInfo.from(user);
     }