Loan Management System 🏦

A Spring Boot application that allows customers and admins to manage loans, track payments, and apply discounts/penalties based on payment timing.

📌 Features

• Admin Features: Create loans for any customer, view all loans, and process payments.
• Customer Features: View their loans, pay installments, and track outstanding balances.
• Loan Payments: Apply early payment discounts and late payment penalties.
• Security: JWT-based authentication with role-based access control.

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🚀 Technologies Used

• Java 23
• Spring Boot 3
• Spring Security (JWT)
• Spring Data JPA (H2 Database - In-Memory)
• Gradle
• JUnit & Mockito (for testing)

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🔧 Prerequisites

Before running the application, make sure you have:

• Java 23 installed → Download Java
• Gradle installed → Install Gradle
• Postman (Optional) for API testing → Download Postman

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📥 Setup & Run the Application

1️⃣ Clone the Repository

git clone https://github.com/capraztarik/loan.git
cd loan-management

2️⃣ Build the Project with Gradle

./gradlew clean build

3️⃣ Run the Application

./gradlew bootRun

4️⃣ View the Database

Since we are using an H2 in-memory database, you can access the database console in your browser:

Open: http://localhost:8080/h2-console
Use the following credentials:
JDBC URL: jdbc:h2:mem:testdb
Username: sa
Password: password

API Endpoints

Authentication

Method	Endpoint	Description
POST	/auth/register	Register a new user (Admin/Customer)
POST	/auth/login	Authenticate and get JWT token

Loan Management

Method	Endpoint	Description
POST	/loans/create	Create a new loan (Admin/Customer)
GET	/loans/customer/{customerId}	Get loans for a customer
POST	/installments/pay	Pay installments
GET     /installments/loan/{loanId} Get installments of a loan

Run Tests

Run All Tests
./gradlew test 
With report: ./gradlew clean test jacocoTestReport 
You can find coverage report: build/reports/jacoco/test/html/index.html

Postman documentation

https://documenter.getpostman.com/view/39752670/2sAYXFiHRz