Spring Sandbox

This is a ready-to-code environment for learning Java and the Spring Boot framework for building web apps and REST APIs. It comes with the OpenJDK and Maven pre-installed and a full offline Maven repository pre-cached — including Spring Boot and popular starters — so you can build and run real Spring applications right in your browser with no setup, no installs, and no internet connection. A complete, runnable sample project (a Books REST API backed by an in-memory database) is included to get you productive in minutes.