A simple JavaFX application based off the OpenJFX getting started documentation that uses Gradle as the build system.
The project was created using the standard IntelliJ IDEA project wizard for creating Gradle projects.
This uses the JavaFX Gradle plugin and Gradle 6.8.
This application can be run from the command line:
./gradlew clean run
and via calling that task from the IntelliJ IDEA Gradle window.
It does NOT run if you run application class itself in IntelliJ IDEA.