The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
SDKMAN! installs each Java distribution and version you ask for in its own folder under ~/.sdkman/candidates/java, plus a current link pointing to your default. Each JDK typically takes 200 to 400 MB, and versions installed for one project tend to stay.
JDKs installed with SDKMAN!. Keep the default and the ones your projects use; others can be installed again.
What happens if you delete it?
A removed version can be installed again with sdk install java <version>; SDKMAN! does not do it automatically unless a project uses an .sdkmanrc file and you run sdk env install.
How to remove it properly
Run sdk list java to see what is installed and sdk current java to see your default, then sdk uninstall java <version> for each version you no longer need. This is SDKMAN!’s own command and deletes permanently.
Quit the app that uses it, then move it to the Trash. Empty the Trash when you’re sure.
Before you delete it
Do not remove the default version or the current link; to retire your default, switch first with sdk default java <version>.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
Frequently asked questions
Can I delete Java versions installed with SDKMAN!?
Usually, after a check. Might hold something you care about. Look inside before removing it. A removed version can be installed again with sdk install java <version>; SDKMAN! does not do it automatically unless a project uses an .sdkmanrc file and you run sdk env install.
Will Java versions (SDKMAN!) come back after I delete it?
Yes. A removed version can be installed again with sdk install java <version>; SDKMAN! does not do it automatically unless a project uses an .sdkmanrc file and you run sdk env install.
How do I remove Java versions (SDKMAN!) properly?
Run sdk list java to see what is installed and sdk current java to see your default, then sdk uninstall java <version> for each version you no longer need. This is SDKMAN!’s own command and deletes permanently.