Banking REST API

A full-featured RESTful banking API built with Spring Boot, featuring user management, account operations, transactions, transfers, and loan processing.

Features

• User Management — Registration, authentication, profile updates
• Account Operations — Create accounts, check balances, deposit, withdraw
• Fund Transfers — Transfer money between accounts with validation
• Transaction History — Track all account activity
• Loan Processing — Apply for loans, track repayments, manage loan status
• Security — Spring Security with role-based access control

Tech Stack

Layer	Technology
Framework	Spring Boot 3.4.3
Language	Java 21
Database	MySQL 8.0
ORM	Spring Data JPA / Hibernate
Security	Spring Security
Build	Maven
Cloud	AWS RDS (Production)

---

Quick Start

Prerequisites

• Java 21 — Download
• Docker — Download (for local MySQL database)
• Maven — Included via ./mvnw wrapper (no install needed)

1. Clone the Repository

git clone https://github.com/olael94/banking-api.git
cd banking-api

2. Set Up Environment

cp .env.example .env

The default .env is pre-configured for Docker MySQL — no changes needed for local development.

3. Start the Database

docker-compose up -d

This starts a MySQL 8.0 container with the database ready to use.

4. Run the Application

./mvnw spring-boot:run

5. Access the API

The API is now running at: http://localhost:8080

Test it:

curl http://localhost:8080/api/users

---

Using AWS RDS Instead of Docker

If you prefer to use AWS RDS:

1. Edit your .env file
2. Comment out Option 1 (Docker)
3. Uncomment Option 2 (AWS RDS) and fill in your credentials

# Option 1: Docker MySQL — COMMENT THESE OUT
# SPRING_DATASOURCE_URL=jdbc:mysql://localhost:3306/banking_application
# SPRING_DATASOURCE_USERNAME=banking_user
# SPRING_DATASOURCE_PASSWORD=banking_password

# Option 2: AWS RDS — UNCOMMENT AND FILL IN
SPRING_DATASOURCE_URL=jdbc:mysql://your-rds-endpoint:3306/banking_application
SPRING_DATASOURCE_USERNAME=admin
SPRING_DATASOURCE_PASSWORD=your-password

See docs/aws-setup.md for detailed AWS RDS setup instructions.

---

API Endpoints

Users

Method	Endpoint	Description
POST	/api/users/register	Register new user
GET	/api/users/{id}	Get user details
PUT	/api/users/{id}	Update user
DELETE	/api/users/{id}	Delete user

Accounts

Method	Endpoint	Description
POST	/api/accounts	Create account
GET	/api/accounts/{id}	Get account details
POST	/api/accounts/{id}/deposit	Deposit funds
POST	/api/accounts/{id}/withdraw	Withdraw funds
POST	/api/accounts/transfer	Transfer between accounts
DELETE	/api/accounts/{id}	Close account

Transactions

Method	Endpoint	Description
GET	/api/transactions/{accountId}	Get transaction history
POST	/api/transactions	Create transaction

Transfers

Method	Endpoint	Description
POST	/api/transfers	Initiate transfer
GET	/api/transfers/{id}	Get transfer details

Loans

Method	Endpoint	Description
POST	/api/loans/apply	Apply for loan
GET	/api/loans/{id}	Get loan details
POST	/api/loans/{id}/repay	Make loan payment

---

Project Structure

banking-api/
│
├── src/main/java/edu/ensign/cs460/banking_api/
│   ├── controller/          # REST API endpoints
│   ├── service/             # Business logic interfaces
│   │   └── impl/            # Service implementations
│   ├── repository/          # Data access layer (JPA)
│   ├── models/              # JPA entities
│   ├── dto/                 # Data transfer objects
│   ├── exception/           # Custom exceptions & global handler
│   ├── config/              # Security & app configuration
│   └── security/            # Authentication components
│
├── src/main/resources/
│   └── application.properties
│
├── src/test/                # Unit & integration tests
├── sql/                     # Database schema scripts
├── docs/                    # Documentation
│   └── aws-setup.md         # AWS RDS setup guide
│
├── .env.example             # Environment variables template
├── docker-compose.yml       # Local MySQL database
├── pom.xml                  # Maven dependencies
└── README.md

---

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                           Client                                 │
└─────────────────────────────┬───────────────────────────────────┘
                              │ HTTP
                              ▼
┌─────────────────────────────────────────────────────────────────┐
│                        Controllers                               │
│         REST endpoints for Users, Accounts, Loans, etc.          │
├─────────────────────────────────────────────────────────────────┤
│                         Services                                 │
│              Business logic & validation                         │
├─────────────────────────────────────────────────────────────────┤
│                       Repositories                               │
│                    JPA Data Access Layer                         │
├─────────────────────────────────────────────────────────────────┤
│                      MySQL Database                              │
│           (Docker for local / AWS RDS for production)            │
└─────────────────────────────────────────────────────────────────┘

---

Database Schema

┌──────────────┐       ┌──────────────┐       ┌──────────────┐
│     USER     │       │   ACCOUNT    │       │ TRANSACTION  │
├──────────────┤       ├──────────────┤       ├──────────────┤
│ user_id (PK) │───┐   │ account_id   │───┐   │ transaction_id│
│ username     │   │   │ user_id (FK) │   │   │ account_id(FK)│
│ password     │   └──►│ account_num  │   └──►│ type         │
│ email        │       │ account_type │       │ amount       │
│ full_name    │       │ balance      │       │ date         │
│ dob          │       │ status       │       │ status       │
│ reg_date     │       └──────────────┘       └──────────────┘
└──────────────┘
        │
        │              ┌──────────────┐       ┌──────────────┐
        │              │   TRANSFER   │       │     LOAN     │
        │              ├──────────────┤       ├──────────────┤
        │              │ transfer_id  │       │ loan_id      │
        │              │ from_acct(FK)│       │ user_id (FK) │
        │              │ to_acct (FK) │       │ loan_type    │
        │              │ amount       │       │ amount       │
        │              │ date         │       │ interest_rate│
        └─────────────►│ status       │       │ status       │
                       └──────────────┘       └──────────────┘

---

Configuration

Environment variables are loaded automatically from .env via spring-dotenv.

Variable	Description	Default
SPRING_DATASOURCE_URL	JDBC connection URL	jdbc:mysql://localhost:3306/banking_application
SPRING_DATASOURCE_USERNAME	Database username	banking_user
SPRING_DATASOURCE_PASSWORD	Database password	banking_password
SERVER_PORT	Application port	8080
SPRING_JPA_HIBERNATE_DDL_AUTO	Schema generation	update

---

Common Commands

# Start MySQL database
docker-compose up -d

# Stop MySQL database (keeps data)
docker-compose down

# Stop MySQL and delete all data
docker-compose down -v

# Run the application
./mvnw spring-boot:run

# Run tests
./mvnw test

# Build JAR file
./mvnw clean package

# Run JAR file
java -jar target/banking-api-0.0.1-SNAPSHOT.jar

---

Troubleshooting

"Connection refused" error

Make sure MySQL is running:

docker-compose ps

If it's not running:

docker-compose up -d

"Access denied" error

Check your .env file has the correct credentials matching docker-compose.yml:

• Username: banking_user
• Password: banking_password

Port 3306 already in use

Stop any existing MySQL service:

# macOS
brew services stop mysql

# Linux
sudo systemctl stop mysql

# Or change the port in docker-compose.yml
ports:
  - "3307:3306"  # Use port 3307 instead

Port 8080 already in use

Change the port in your .env file:

SERVER_PORT=8081

---

Running Tests

# Run all tests
./mvnw test

# Run a specific test class
./mvnw test -Dtest=UserServiceImplTest

# Run with coverage report
./mvnw test jacoco:report

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License

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