Design and implement a RESTful API (including data model and the backing implementation) for money transfers between accounts.

1. In project directory run gradlew clean build on Windows or ./gradlew clean build on UN*X to compile, run tests and package the application.
2. Go to build/libs and run the application via java -jar transfer-service.jar. It will start server on 8080 port (if you want to change the port, you should run application via java -Dhttp.port=other_port_number -jar transfer-service.jar, where other_port_number - number of http port which you prefer).

1. Javalin - A simple web framework
2. H2 - Java SQL database
3. Flyway - A database migration tool
4. Guice - DI framework
5. Lombok - An annotation-based code generator

1. H2 is used as data storage. This causes a file system to become clogged with database stuff (doesn't take up much space, because when the application starts and stops, flyway is clearing the data).
2. The application supports transactions only on DAO-level.

All requests to the API are relative http://localhost:port

{
    "id": id,
    "balance": balance
}

{
    "id": id,
    "balance": balance
}