💰 Expense Split Application
A full-stack web application to manage and split expenses among groups, similar to Splitwise. This project is built using Spring Boot (Backend) and HTML, CSS, JavaScript (Frontend).
🚀 Features
👤 User Management: Create and manage users
👥 Group Management: Create groups and add members,
💸 Expense Management: Add expenses within groups, Split expenses among members
🔄 Settlement System: Track balances, Settle debts between users
📊 Net Balance Calculation: Optimized settlement logic to minimize transactions
🛠️ Tech Stack
🔹 Backend-- Java, Spring Boot, Spring Web, Spring Data JPA, REST APIs
🔹 Frontend-- HTML, CSS, JavaScript
🔹 Database-- (Configured via application.properties, likely MySQL or H2)
⚙️ Backend Architecture
The backend follows a layered architecture:
- Controller Layer
Handles HTTP requests:UserController, GroupController, ExpensesController, TransactionController
- Service Layer
Contains business logic:Expense splitting logic, Balance calculation, Settlement optimization
- Repository Layer
Uses Spring Data JPA:Interfaces for database operations
- Entity Layer
Main entities:User, Group, Expenses, Split, Transactions, Members
- DTOs
Request & Response objects, Clean API structure
- Exception Handling
Global exception handler
Custom exceptions:UserNotFoundException, GroupNotFoundException, SplitNotFoundException
🔗 API Endpoints (Overview)
👤 User APIs Create User Get Users
👥 Group APIs Create Group Add Members Get Group Details
💸 Expense APIs Add Expense Split Expense Get Expense Details
🔄 Transaction APIs Settle Payments Get Balance Summary
🧠 Core Logic Expense Splitting Equal split among group members Tracks who owes whom Net Settlement Minimizes number of transactions Converts multiple debts into optimized payments
🔹 Backend--
Navigate to project folder
cd Expense-Split
Run Spring Boot app:
mvn spring-boot:run
Server runs at:
🔹 Frontend--
Open index.html in browser
OR
Serve using Live Server (recommended)
🧪 Testing--
Postman collection available in project
Test all APIs using provided endpoints
📌 Future Enhancements
🔐 Authentication & Authorization (JWT)
📱 Mobile responsive UI improvements
📊 Advanced analytics (charts)
📧 Notifications & reminders
💳 Payment integration
🤝 Contribution
Feel free to fork this repository and contribute!