Kleer - Currency Exchange Application

A full-stack currency exchange application with Riksbank integration. The backend provides exchange rate data and conversion services, while the frontend offers a user-friendly interface for currency conversions.

Prerequisites

Before running this project, ensure you have the following installed:

• Java 21 or higher
• Node.js (v16 or higher recommended)
• npm (comes with Node.js)
• Maven (optional - the project includes Maven wrapper)

Project Structure

kleer/
├── backend/        # Spring Boot backend (Java 21)
└── frontend/       # React + TypeScript frontend (Vite)

Quick Start

1. Running the Backend

The backend is a Spring Boot application that runs on port 8080.

# Navigate to the backend directory
cd backend

# On Windows - Use the custom build script
build.cmd

# On macOS/Linux
./mvnw spring-boot:run

The backend will start at http://localhost:8080

Alternative: If you have Maven installed globally:

cd backend
mvn spring-boot:run

2. Running the Frontend

The frontend is a React application that runs on port 5173 (default Vite port).

# Navigate to the frontend directory
cd frontend

# Install dependencies (first time only)
npm install

# Start the development server
npm run dev

The frontend will start at http://localhost:5173

Additional Information

Backend Features

• API Base URL: http://localhost:8080
• Database: H2 in-memory database (no setup required)
• H2 Console: Available at http://localhost:8080/h2-console
  • JDBC URL: jdbc:h2:mem:currencydb
  • Username: sa
  • Password: (leave empty)

Frontend Features

• React 19 with TypeScript
• Vite for fast development and building
• Modern UI for currency exchange

Building for Production

Backend:

cd backend

# Build and run with custom script (Windows)
build.cmd

# OR manually run the existing JAR
java -jar target/currency-exchange-1.0.0.jar

Frontend:

cd frontend
npm run build

# Preview the production build
npm run preview

Troubleshooting

• JAVA_HOME not set (Windows): The build.cmd script requires JAVA_HOME to be set. Set it with:

  set JAVA_HOME=C:\path\to\your\jdk-21

• Port conflicts: If port 8080 or 5173 is already in use, you'll need to stop the conflicting service or modify the port configuration.
• Java version: Ensure you're using Java 21. Check with java -version
• Node version: Check your Node version with node -v
• Backend not connecting to Riksbank API: Check your internet connection and firewall settings.

Development

• Backend hot reload: Spring Boot DevTools is included for automatic restarts
• Frontend hot reload: Vite provides instant HMR (Hot Module Replacement)

License

None. This project is part of the Kleer application process for dev role.