🔐 Expense Tracker

A secure and scalable authentication backend built with Java Spring Boot, featuring JWT-based authentication, BCrypt password hashing, PostgreSQL integration, and custom exception handling. Ideal for modern web and mobile applications.

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🛠️ Tech Stack

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🚀 Features

• ✅ User registration and login via RESTful APIs
• 🔐 Secure password hashing using BCrypt
• 🛡️ JWT token generation & validation
• 🧪 Unit-tested authentication flow
• 📂 Layered architecture (Controller → Service → Repository)
• ⚠️ Custom exception classes for clear error handling
• 🕐 Brute force protection with account timeout

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📁 Project Structure

src/
├── main/
│   ├── java/
│   │   └── com.expenses.expensetracker/
│   │       ├── controller/
│   │       ├── service/
│   │       ├── repository/
│   │       ├── filters/
│   │       └── exceptions/
│   └── resources/
│       └── pages/
│           ├── Categories.py
│           └──Transactions.py
│       ├── Homepage.py        │
│       └── application.properties
└── test/

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📦 Setup Instructions

1. Clone the repo
   git clone https://github.com/your-username/expenseTracker.git

2. Configure database in application.properties - set all necessary environment variables

3. Create a Spring service Java class to configure your API Key for JWT Authentication.

4. Run the app
   mvn spring-boot:run or run from your IDE

5. Test API endpoints
   Use Postman or curl to test /api/users/register and /api/users/login

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