vvr-vikram/enterprise-order-system

Purpose and Runtime

A single-process Spring Boot enterprise order system consolidates user, order, payment, and inventory domains. It exposes HTTP APIs on port 8080 and uses local MySQL ACID transactions rather than Kafka, an API gateway, or distributed sagas. Main entry point: enterprise-order-system/src/main/java/com/enterprise/order/EnterpriseOrderApplication.java.

HTTP and API Boundary

REST controllers are the external boundary for user lookup, order creation/status, and direct payment processing:

• enterprise-order-system/src/main/java/com/enterprise/order/controller/OrderController.java

• enterprise-order-system/src/main/java/com/enterprise/order/controller/PaymentController.java

• enterprise-order-system/src/main/java/com/enterprise/order/controller/UserController.java

Order request/response contracts reside in enterprise-order-system/src/main/java/com/enterprise/order/common/OrderRequest.java and enterprise-order-system/src/main/java/com/enterprise/order/common/OrderResponse.java. Cross-cutting API error translation is centralized in enterprise-order-system/src/main/java/com/enterprise/order/common/GlobalExceptionHandler.java.

Order Orchestration and Transaction Boundary

OrderService is the primary business-process coordinator:

• enterprise-order-system/src/main/java/com/enterprise/order/order/OrderService.java

• enterprise-order-system/src/main/java/com/enterprise/order/order/Order.java

• enterprise-order-system/src/main/java/com/enterprise/order/order/OrderRepository.java

For POST /orders, it handles the client Idempotency-Key, creates a pending order, invokes payment processing and inventory reservation in-process, then marks the order completed. Failure in payment or stock reservation propagates through the local transaction, rolling back order, payment, and inventory changes together. Persisted orders also provide the status-query source of truth.

Payment Domain

Payment is a local service dependency of order creation and is also directly callable through its controller. The domain records simulated payment debits/logs via:

• enterprise-order-system/src/main/java/com/enterprise/order/payment/PaymentService.java

• enterprise-order-system/src/main/java/com/enterprise/order/payment/Payment.java

• enterprise-order-system/src/main/java/com/enterprise/order/payment/PaymentRepository.java

Its failure conditions, such as a payment limit being exceeded, are transaction-significant: they abort the enclosing order workflow rather than triggering compensating messages.

Inventory Domain

Inventory owns stock state and reservation records:

• enterprise-order-system/src/main/java/com/enterprise/order/inventory/InventoryService.java

• enterprise-order-system/src/main/java/com/enterprise/order/inventory/Inventory.java

• enterprise-order-system/src/main/java/com/enterprise/order/inventory/OrderReservation.java

During order creation, reservation decrements available product stock. Insufficient inventory throws an error and relies on the same database transaction rollback to restore all affected state. Reservation persistence is separated through OrderReservationRepository.java.

User Domain

User data is a supporting validation/read domain used by the application’s user endpoint and order-related business validation:

• enterprise-order-system/src/main/java/com/enterprise/order/user/UserService.java

• enterprise-order-system/src/main/java/com/enterprise/order/user/User.java

• enterprise-order-system/src/main/java/com/enterprise/order/user/UserRepository.java

Persistence and Infrastructure

The sole material external service is local MySQL, expected as enterprise_order_db on port 3306. Spring Boot/JPA-style repositories form the persistence boundary; schema and initial mock data are supplied in:

• enterprise-order-system/src/main/resources/application.properties

• enterprise-order-system/src/main/resources/sql/schema.sql

• enterprise-order-system/src/main/resources/sql/seed-data.sql

The Maven build is defined by enterprise-order-system/pom.xml; Java 17+ is required.