🏦 Online Banking System Backend

A robust, secure banking backend API built with Spring Boot 3.2.4 and Java 21, featuring comprehensive banking operations, JWT authentication, and email integration.

🌟 Features

🔐 Authentication & Security

• JWT-based authentication with refresh token support
• Role-based authorization (Customer/Admin)
• Password strength validation
• OTP verification for account activation
• Secure password hashing with BCrypt

💰 Core Banking Operations

• Account creation and management
• Money deposit and withdrawal
• Fund transfers between accounts
• Balance inquiries and transaction history
• Transaction limits management
• Real-time balance updates

📧 Communication (Enable or Disable in property file)

• Email notifications with HTML templates
• OTP generation and verification
• Welcome emails for new customers
• Password reset notifications

🛡️ Security Features

• Global exception handling
• Input validation
• Transaction logging
• Account suspension capabilities
• Secure API endpoints

🛠️ Tech Stack

Backend Framework

• Java 21 - Latest LTS version
• Spring Boot 3.2.4 - Main framework
• Spring Security 6.2.4 - Authentication & authorization
• Spring Data JPA - Data persistence
• Hibernate - ORM framework

Database

• MySQL 8.0 - Production database
• H2 - In-memory database for testing

Security & Authentication

• JWT (jjwt) 0.12.5 - Token management
• BCrypt - Password hashing

Email & Templates

• Spring Boot Mail - Email service
• Thymeleaf - HTML email templates

Build & Deployment

• Maven 3.10.1 - Build tool
• Docker & Docker Compose - Containerization
• JUnit 5 - Testing framework

🚀 Getting Started

Prerequisites

• Java 21 JDK
• Maven 3.10.1+
• MySQL 8.0 (or Docker)
• Git

Environment Setup

1. Clone the repository

   git clone https://github.com/devhnry/online-banking-backend.git
   cd online-banking-backend

2. Set up environment variables (Depending on 'dev or qa' environment)

   # Database Configuration
   export DATABASE_NAME=your_db_name
   export DATABASE_USERNAME=your_db_username
   export DATABASE_PASSWORD=your_db_password
   
   # Email Configuration (Gmail SMTP)
   export EMAIL_HOST=smtp.gmail.com
   export EMAIL_PASSWORD=your_app_password
   export [email protected]
   export EMAIL_PORT=587

3. Database Setup

   CREATE DATABASE onlinebanking;
   CREATE USER 'banking_user'@'localhost' IDENTIFIED BY 'your_password';
   GRANT ALL PRIVILEGES ON onlinebanking.* TO 'banking_user'@'localhost';

Running the Application

Local Development

# Install dependencies
mvn clean install

# Run the application
mvn spring-boot:run

Accessing the Application

• API Base URL: http://localhost:6000
• H2 Console (Development): http://localhost:6000/h2-console
• Health Check: GET http://localhost:6000/actuator/health

📋 API Documentation

Authentication Endpoints

Method	Endpoint	Description	Auth Required
POST	/auth/onboard	Register new customer	❌
POST	/auth/send-otp	Send OTP for verification	❌
POST	/auth/onboard/verify-otp	Verify OTP and activate account	❌
POST	/auth/login	Customer login	❌
POST	/auth/refresh-token	Refresh access token	❌
POST	/auth/login	Customer login	❌
POST	/auth/refresh-token	Refresh access token	❌

Account Management

Method	Endpoint	Description	Auth Required
GET	/api/v1/account/get-details	Get customer details	✅
GET	/api/v1/account/view-balance	Check account balance	✅
POST	/api/v1/account/make-deposit	Deposit money	✅
POST	/api/v1/account/withdraw	Withdraw money	✅
POST	/api/v1/account/make-transfer	Transfer funds	✅
POST	/api/v1/account/get-transfer-summary	Get transfer summary	✅
GET	/api/v1/account/details	Get account holder name	✅
GET	/api/v1/account/view-bank-statement	View transaction history	✅
PUT	/api/v1/account/change-password	Change password	✅
PATCH	/api/v1/account/update-profile	Update profile information	✅
PUT	/api/v1/account/update-transaction-limit	Update transaction limit	✅

Currently Inactive Endpoints

⚠️ Note: The following endpoints exist in the codebase but are not fully implemented:

Method	Endpoint	Description	Status
PUT	/api/v1/admin/suspend/{id}	Suspend user account	🚧 Returns empty response
GET	/api/v1/account/send-otp	Generate OTP	🚧 Returns empty response
PUT	/api/v1/account/forgot-password	Reset password	🚧 Returns empty response

Kora Virtual Account endpoints (/api/v1/kora/**) are commented out and not active.

Test Database

The application uses H2 in-memory database for testing with automatic schema generation.

📁 Project Structure

src/
├── main/
│   ├── java/org/henry/bankingsystem/
│   │   ├── config/              # Security & application configuration
│   │   ├── controller/          # REST API endpoints
│   │   ├── dto/                 # Data Transfer Objects
│   │   ├── entity/              # JPA entities
│   │   ├── enums/               # Enumerations
│   │   ├── exceptions/          # Custom exceptions & handlers
│   │   ├── repository/          # Data access layer
│   │   ├── service/             # Business logic
│   │   └── utils/               # Utility classes
│   └── resources/
│       ├── templates/           # Email templates
│       └── application*.yml     # Configuration files
└── test/                        # Test files

🔧 Configuration

Application Profiles

• dev: Development environment with local MySQL
• qa: Testing environment with cloud database

Key Configuration Properties

server:
  port: 6000

spring:
  profiles:
    active: dev
  
  datasource:
    url: jdbc:mysql://localhost:3306/${DATABASE_NAME}
    username: ${DATABASE_USERNAME}
    password: ${DATABASE_PASSWORD}

🔐 Security Implementation

JWT Configuration

• Access token expiry: 24 hours
• Refresh token for seamless authentication
• Stateless session management

Password Security

• BCrypt hashing with strength 12
• Password strength validation (uppercase, numbers, special characters)
• 4-digit PIN for transactions

API Security

• All endpoints except auth require valid JWT
• Role-based access control
• Request/response logging for audit

👨‍💻 Author

Henry

• LinkedIn: https://www.linkedin.com/in/henry-taiwo-b60198313/
• X: https://x.com/h3nry0x
• Email: [email protected]

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Postman Collection

• https://www.postman.com/spaceflight-explorer-98033499/online-banking-system/collection/0iru7yg/online-banking-system-api?action=share&creator=40620161

📞 Support

For support, email me at [email protected] or create an issue in this repository.