Just: A New CLI for Spring Boot Applications – Features, Installation, and Usage

The piece presents Just , a command‑line utility created by Maciej Walkowiak that enhances the development experience of Spring Boot applications by automatically detecting source changes, rebuilding, and hot‑reloading the app without manual configuration.

Just leverages picocli to implement rich CLI features, integrates with Testcontainers for container‑based JUnit tests, uses Sentry for error monitoring, and employs JReleaser for publishing releases.

Key capabilities include:

Automatic detection of changes in pom.xml or build.gradle that pauses the running app and restarts it after the build finishes.

The run sub‑command starts required infrastructure (databases, Docker‑compose services) before launching the app.

The build sub‑command translates to the appropriate Maven or Gradle command and supports options such as --quick to skip tests, documentation, formatting, and static analysis, producing JAR, native, or Docker images.

The format sub‑command formats code according to project settings and Spotless rules.

The kill sub‑command terminates running processes, with customizable ports.

Installation methods are provided for different platforms:

macOS: brew install maciejwalkowiak/brew/just Windows:

scoop bucket add maciejwalkowiak https://github.com/maciejwalkowiak/scoop-just.git

followed by scoop install just Linux (manual): download the zip, unzip, make the binary executable, and move it to /usr/local/bin/just.

After installation, the just help command verifies the setup. The tool is currently in an Alpha testing phase, free to use but with built‑in expiration that may require a purchase or update after the trial period.

For more details, refer to the original InfoQ article “Just, a New CLI for Spring Boot Applications” and the linked documentation.