We've been using Grails (Groovy) at our startup with great success. A few warts early on with regard to how Grails wants to handle packages and URLs, but we push a lot of transactions through this system (sorry, I don't have exact numbers) and Grails has held up remarkably well. It also cut our initial development time by about half.

Stripes is a great framework that promotes the "convention over configuration" mentality, and is quite minimalistic. But it doesn't support any specific ORM out-of-the-box, and doesn't have scripts to autogenerate a lot of stuff, so I'm not sure I'd call it "Rails-like." But it's been one of my favorite Java web frameworks to use.