Food Ordering System

Table of Contents

• Overview
• Features
• Architecture
• Technologies Used
• Project Structure
• Installation and Setup
• Usage
  • API Endpoints
  • Sample Request
• Data Flow
• Development Guidelines
  • Adding a New Feature
  • Testing
• Contributing
• License
• Contact

Overview

Food Ordering System is a backend application built using a microservices architecture to facilitate seamless and efficient food ordering processes. Customers can place orders from various restaurants, make secure payments, and receive real-time updates, while restaurants can manage orders and menus effectively.

This README will be continuously updated to reflect the latest changes and improvements as the project progresses.

Features

• Order Management: Place, track, and manage food orders.
• Payment Processing: Secure and reliable payment transactions.
• Restaurant Interface: Restaurants can approve or reject orders.
• Customer Profiles: Manage customer information and order history.
• Real-Time Notifications: Updates via Apache Kafka messaging.
• Reliable Messaging with Outbox Pattern: Ensures consistent and reliable message delivery between services.

Architecture

The project follows the Hexagonal Architecture (Ports and Adapters) pattern, emphasizing Domain-Driven Design (DDD) and Clean Architecture principles. This ensures a clear separation of concerns and promotes scalability and maintainability.

• Domain Layer: Contains business logic and domain entities.
• Application Layer: Coordinates application activities and use cases.
• Infrastructure Layer: Deals with external systems like databases and messaging.
• Outbox Pattern Implementation: Ensures reliable communication between microservices by persisting messages in an outbox table in the database and then publishing them to the message broker.

Technologies Used

• Programming Language: Java 17
• Frameworks and Libraries:
  • Spring Boot
  • Spring Data JPA
  • Spring Transaction Management
• Messaging and Streaming: Apache Kafka
• Database: PostgreSQL
• Containerization: Docker
• Build Tool: Maven

Project Structure

The project is modularized, reflecting its microservices architecture:

Common Modules

• common: Shared utilities and code across microservices.
• infrastructure: Infrastructure components like Kafka configurations and Outbox pattern implementations.

Microservice Modules

Each microservice comprises:

• domain: Domain models and core business logic.
• application: Application services and use cases.
• dataaccess: Data repositories and database interactions.
• messaging: Kafka producers and consumers.
• outbox: Components related to the Outbox pattern for reliable message handling.
• container: Spring Boot application entry point.

Installation and Setup

Prerequisites

• Java Development Kit (JDK) 17
• Maven
• Docker & Docker Compose

Steps

1. Clone the Repository

   git clone https://github.com/sogutemir/FoodOrderingSystem.git
   

2. Navigate to the Project Directory

   cd FoodOrderingSystem
   

3. Build the Project

   mvn clean package
   

4. Start Docker Containers

   Ensure that Docker is running, then start the required services:

   docker-compose -f common.yml -f init_kafka.yml up -d
   docker-compose -f common.yml -f kafka_cluster.yml up -d
   docker-compose -f common.yml -f zookeeper.yml up -d
   

5. Run Microservices

   Open separate terminals for each microservice and run:

   # Order Service
   java -jar order-service/order-container/target/order-container-1.0-SNAPSHOT.jar
   
   # Payment Service
   java -jar payment-service/payment-container/target/payment-container-1.0-SNAPSHOT.jar
   
   # Restaurant Service
   java -jar restaurant-service/restaurant-container/target/restaurant-container-1.0-SNAPSHOT.jar
   
   # Customer Service
   java -jar customer-service/customer-container/target/customer-container-1.0-SNAPSHOT.jar
   

Usage

API Endpoints

The application exposes RESTful APIs for interaction. Here are some of the key endpoints:

• Order Service
  • Create Order: POST /orders
  • Get Order Details: GET /orders/{orderId}
  • Update Order: PUT /orders/{orderId}
  • Delete Order: DELETE /orders/{orderId}
• Payment Service
  • Process Payment: POST /payments
• Restaurant Service
  • Approve Order: POST /restaurants/{restaurantId}/orders/{orderId}/approve
  • Reject Order: POST /restaurants/{restaurantId}/orders/{orderId}/reject
• Customer Service
  • Register Customer: POST /customers
  • Get Customer Info: GET /customers/{customerId}

Sample Request

Create Order

Endpoint: POST http://localhost:8181/orders

Headers:

• Content-Type: application/json

Request Body:

{
  "customerId": "d215b5f8-0249-4dc5-89a3-51fd148cfb41",
  "restaurantId": "d215b5f8-0249-4dc5-89a3-51fd148cfb45",
  "address": {
    "street": "Main Street",
    "postalCode": "12345",
    "city": "Amsterdam"
  },
  "price": 200.00,
  "items": [
    {
      "productId": "product-1",
      "quantity": 1,
      "price": 50.00,
      "subTotal": 50.00
    },
    {
      "productId": "product-2",
      "quantity": 3,
      "price": 50.00,
      "subTotal": 150.00
    }
  ]
}

Response:

{
  "orderId": "order-123",
  "status": "PENDING",
  "message": "Order created successfully."
}

For detailed API documentation, refer to the API Documentation.

Data Flow

1. Order Placement: Customer places an order via the Order Service.
2. Outbox Logging: The Order Service saves the order and writes an event to the outbox table within the same transaction.
3. Message Dispatch: A background process reads events from the outbox table and publishes them to Apache Kafka.
4. Payment Processing: The Payment Service consumes the event from Kafka, processes the payment, and uses the Outbox pattern to communicate back.
5. Order Approval: The Restaurant Service receives the event, approves the order, and updates the order status.
6. Notification: The customer receives updates on the order status.

By utilizing the Outbox pattern, we ensure that message delivery between microservices is reliable and consistent, maintaining data integrity across services.

Development Guidelines

Adding a New Feature

1. Domain Layer

   • Define new entities or value objects.
   • Implement business logic and rules.

2. Application Layer

   • Create or update application services.
   • Define use cases.

3. Data Access Layer

   • Add or modify repository interfaces.
   • Implement data access logic.
   • Implement Outbox entities and repositories if necessary.

4. Messaging

   • Update Kafka producers and consumers.
   • Define new topics if necessary.
   • Ensure messages are written to the Outbox table within the same transaction as the domain event.

5. API Layer

   • Update controllers.
   • Define new endpoints.

Testing

• Unit Tests: Use JUnit and Mockito.
• Integration Tests: Use Testcontainers for databases and Kafka.
• End-to-End Tests: Validate the complete workflow.
• Outbox Pattern Tests: Ensure that events are correctly written to and read from the outbox table.

Contributing

We welcome contributions! To contribute:

1. Fork the Project

   git clone https://github.com/your-username/FoodOrderingSystem.git
   

2. Create a Feature Branch

   git checkout -b feature/YourFeatureName
   

3. Commit Your Changes

   git commit -m "Add YourFeatureName"
   

4. Push to the Branch

   git push origin feature/YourFeatureName
   

5. Open a Pull Request

   Submit your pull request, and we will review it as soon as possible.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contact

Emir SoGood

• GitHub: @sogutemir
• Email: [email protected]

Project Link: FoodOrderingSystem