activemq-artemis/docs/hacking-guide/en/formatting.md

Code Formatting

Eclipse code formatting and (basic) project configuration files can be found at the etc/ folder. You should manually copy them after importing all your projects:

for settings_dir in `find . -type d -name .settings`; do
   \cp -v etc/ide-settings/org.eclipse.jdt.* $settings_dir
done

Do not use the maven-eclipse-plugin to copy the files as it conflicts with m2e.

Idea

If you completed the step described on idea instructions, and selected the code style accordingly you should be ready to go.