Feature(CS/2020/007): Order service project initialize

[AminduBhashana]

This pull request introduces the initial implementation of the Order Service, including a sample product catalog, REST API endpoints, PostgreSQL integration, and essential supporting infrastructure. The changes add core domain entities, DTOs, controllers, exception handling, and configuration for development and documentation.

Backend and Database Integration

• Added PostgreSQL support with Docker Compose, .env.example for environment variables, and relevant dependencies (spring-boot-starter-data-jpa, postgresql, spring-dotenv) for database connectivity and configuration. (docker-compose.yml [1] .env.example [2] pom.xml [3] [4]
• Defined JPA entities for Order, OrderItem, and OrderStatus to represent orders and their items in the database. (Order.java [1] OrderItem.java [2] OrderStatus.java [3]

API Endpoints and Controllers

• Implemented OrderController for order creation and ProductController for exposing the sample product catalog, both with OpenAPI annotations for documentation. (OrderController.java [1] ProductController.java [2]

Domain and DTO Layer

• Introduced DTOs for request and response payloads, including CreateOrderRequest, OrderItemRequest, OrderResponse, OrderItemResponse, ProductResponse, and ErrorResponse for consistent API communication. (CreateOrderRequest.java [1] OrderItemRequest.java [2] OrderResponse.java [3] OrderItemResponse.java [4] ProductResponse.java [5] ErrorResponse.java [6]
• Added a sample in-memory ProductCatalog and its implementation to simulate product lookups. (ProductCatalog.java [1] ProductCatalogSample.java [2]

Supporting Infrastructure

• Added global exception handling for validation errors and missing products, returning standardized error responses. (GlobalExceptionHandler.java [1] ProductNotFoundException.java [2]
• Configured OpenAPI/Swagger for API documentation and added a mapper to convert entities to DTOs. (OpenApiConfig.java [1] OrderMapper.java [2]

Dependency and Version Management

• Downgraded the Spring Boot parent version in pom.xml to 3.5.16 for compatibility with the chosen dependencies. (pom.xml pom.xmlL8-R8)

[Copilot]

Pull request overview

This PR adds the initial Spring Boot–based Order Service, including persistence (JPA/PostgreSQL), REST endpoints for orders and a sample product catalog, OpenAPI/Swagger documentation, and basic exception handling/configuration to support local development.

Changes:

• Added core domain model (Order/OrderItem/OrderStatus), repository, service workflow, and mapping to API DTOs.
• Introduced REST controllers for creating orders and browsing a sample in-memory product catalog, with global exception handling and OpenAPI config.
• Added PostgreSQL + Spring Data JPA + Springdoc + dotenv dependencies and local dev infra via Docker Compose and environment variable examples.

Reviewed changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
src/main/resources/application.yml	Adds datasource/JPA and springdoc configuration.
src/main/java/com/example/orderservice/service/OrderServiceImpl.java	Implements order creation workflow (catalog lookup → totals → persistence).
src/main/java/com/example/orderservice/service/OrderService.java	Defines order creation service contract.
src/main/java/com/example/orderservice/repository/OrderRepository.java	Adds JPA repository for Order persistence.
src/main/java/com/example/orderservice/mapper/OrderMapper.java	Maps persisted Order entity to OrderResponse DTO.
src/main/java/com/example/orderservice/exception/ProductNotFoundException.java	Introduces domain exception for missing products.
src/main/java/com/example/orderservice/exception/GlobalExceptionHandler.java	Adds centralized REST exception handling with ErrorResponse.
src/main/java/com/example/orderservice/entity/OrderStatus.java	Defines order lifecycle status enum.
src/main/java/com/example/orderservice/entity/OrderItem.java	Adds JPA entity for order line items.
src/main/java/com/example/orderservice/entity/Order.java	Adds JPA aggregate root for orders with item relationship.
src/main/java/com/example/orderservice/dto/ProductResponse.java	DTO for sample product catalog responses.
src/main/java/com/example/orderservice/dto/OrderResponse.java	DTO for created order responses.
src/main/java/com/example/orderservice/dto/OrderItemResponse.java	DTO for order item response lines.
src/main/java/com/example/orderservice/dto/OrderItemRequest.java	DTO + validation for incoming order line requests.
src/main/java/com/example/orderservice/dto/ErrorResponse.java	Standardized error payload DTO.
src/main/java/com/example/orderservice/dto/CreateOrderRequest.java	DTO + validation for create-order requests.
src/main/java/com/example/orderservice/controller/ProductController.java	Adds product catalog REST endpoints.
src/main/java/com/example/orderservice/controller/OrderController.java	Adds create-order REST endpoint with OpenAPI annotations.
src/main/java/com/example/orderservice/config/OpenApiConfig.java	Configures OpenAPI metadata for the service.
src/main/java/com/example/orderservice/catalog/ProductCatalogSample.java	Implements in-memory sample product catalog.
src/main/java/com/example/orderservice/catalog/ProductCatalog.java	Defines product catalog abstraction.
pom.xml	Adds JPA/PostgreSQL/springdoc/dotenv dependencies and updates Spring Boot parent.
docker-compose.yml	Adds local Postgres service with healthcheck/volume.
.env.example	Provides example env vars for local Postgres configuration.

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[GLRandula]

Initial code was reviewed