How can one rollback commands in Spring Roo?

Ben Alex has a slideshow introducing Spring Roo.

On slide 8, there is the claim "Even if you make a mistake, Roo will rollback changes!"

I'm unable to find actual documentation of this featur开发者_如何学Pythone. Does anyone know how this can be accomplished?

You cannot roll back, but roo keeps a log, roo.log, so you can repeat everything you've done up until then. And of course, you can just remove what's been added from your source, and usually Roo will update the source for you

If you typed in a command you cannot rollback using roo command line(as far as I know)

You can't roll back, you can keep a backup using the command

perform backup

on your Spring Roo console, or better yet -- use a version control system like Mercurial.