🏦 API Bank

A secure RESTful banking API built with Java and Spring Boot. Supports user registration and authentication via JWT, balance management, fund transfers, and transaction history.

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🚀 Features

• JWT Authentication — Stateless login with token-based authorization
• Role-Based Access Control — USER and ADMIN roles with protected endpoints
• Password Security — BCrypt hashing (strength 12)
• Banking Operations — Cash in, cash out, and peer-to-peer transfers
• Transaction History — Full statement log per user (sent & received)
• Custom Exception Handling — Global error handler with meaningful responses
• Profile Image Support — Upload via file or URL

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🛠️ Tech Stack

Layer	Technology
Language	Java 17
Framework	Spring Boot 3.5
Security	Spring Security + JWT (jjwt 0.12.5)
Persistence	Spring Data JPA / Hibernate
Database	PostgreSQL
Build Tool	Gradle
Utilities	Lombok

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📁 Project Structure

src/main/java/app/bank/
├── configuration/        # JWT filter & Spring Security config
├── controller/           # REST API interfaces
│   └── impl/             # Controller implementations
├── entity/               # JPA entities (User, Statement)
├── exception/            # Custom exceptions
├── repository/           # JPA repositories
└── service/              # Business logic interfaces
    └── impl/             # Service implementations

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📌 API Endpoints

Auth

Method	Endpoint	Access	Description
POST	/bank/user/register	Public	Register new user
POST	/bank/user/login	Public	Login & get JWT

User

Method	Endpoint	Access	Description
GET	/bank/user/balance	Authenticated	Get current balance
GET	/bank/user/statements	Authenticated	Get transaction history
DELETE	/bank/user/delete	Authenticated	Delete own account

Transactions

Method	Endpoint	Access	Description
PUT	/bank/user/cashIn	Authenticated	Deposit funds
PUT	/bank/user/cashOut	Authenticated	Withdraw funds
PUT	/bank/user/transfer	Authenticated	Transfer to another user

Admin

Method	Endpoint	Access	Description
GET	/bank/user/list	ADMIN	List all users

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⚙️ Getting Started

Prerequisites

• Java 17+
• PostgreSQL
• Gradle

1. Clone the repository

git clone https://github.com/your-username/API-bank.git
cd API-bank

2. Configure the database

Edit src/main/resources/application.properties:

spring.datasource.url=jdbc:postgresql://localhost:5432/bankdb
spring.datasource.username=your_username
spring.datasource.password=your_password
spring.jpa.hibernate.ddl-auto=update

3. Run the application

./gradlew bootRun

The API will be available at http://localhost:8080.

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🔐 Authentication

All protected endpoints require a Bearer token in the Authorization header:

Authorization: Bearer <your_jwt_token>

Obtain a token by calling /bank/user/login with your credentials.

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🏗️ Architecture

This project follows Clean Architecture principles with clear separation of concerns:

• Controller layer — Handles HTTP requests and delegates to services
• Service layer — Contains all business logic
• Repository layer — Manages database access via JPA
• Entity layer — Defines the data model