Loan Tracker System

A robust loan management and tracking system built with Spring Boot and React. This application helps manage loans, groups, installments, and payments with a automated allocation system.

🚀 Tech Stack

• Backend: Spring Boot 4.0+ (Java 26)
• Database: PostgreSQL
• ORM: Spring Data JPA with Hibernate
• Frontend: React (located in /frontend)
• Build Tool: Maven

🏗️ Project Architecture

The project follows a standard Spring Boot layered architecture:

• Domain Models: JPA entities representing the database schema (Entry, Group, Payment, InstallmentDetail, etc.).
• Repositories: Spring Data JPA interfaces for database abstraction.
• Services: Business logic layer (e.g., PaymentAllocationService handles the complex logic of applying payments to installments).
• Controllers: REST APIs for frontend-backend communication.

Key Entities

• Entry: Represents a loan or financial entry.
• InstallmentDetail: Breaks down an entry into scheduled payments.
• Payment: Records of actual payments made.
• PaymentAllocation: Tracks how a single payment is distributed across various installments.
• Group/Person: Manages borrowers and organizational structures.

🛠️ Local Setup (PostgreSQL)

To run this project locally, you need to configure your PostgreSQL instance.

1. Database Configuration

The application is configured to look for a database named loan_tracker.

1. Open src/main/resources/application.yml.
2. Update the datasource section if your local settings differ:

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/loan_tracker
    username: your_postgres_username
    password: your_postgres_password # Or set the DB_PASSWORD environment variable

2. Environment Variables

The current configuration uses ${DB_PASSWORD}. You can either:

• Set an environment variable named DB_PASSWORD.
• Replace ${DB_PASSWORD} directly with your password in application.yml.

3. Run the Backend

You can run the application using Maven:

./mvnw spring-boot:run

The server will start on http://localhost:8080.

🎨 Next Phase: Frontend Development

The backend is largely set up with a comprehensive REST API. The next phase involves:

1. Frontend Implementation: Building the user interface in the /frontend directory using React.
2. Integration: The project is already configured with frontend-maven-plugin, which automatically:
   • Installs Node.js and npm.
   • Runs npm install and npm run build.
   • Copies the production build into the Spring Boot static resources.

To work on the frontend independently:

cd frontend
npm install
npm start

📄 License

This project is for internal use as part of the CS 127 Machine Problem.