[Jaepa]

While I would highly highly recommend against it there is GWT, & Vaadin.

They transpile java code to JavaScript, HTML, and css. They are tightly coupled to their RPC apis.

[Bjartr]

I use GWT at work daily. Though we don't use GWT RPC at all and just have normal http endpoints returning JSON on the server, so I wouldn't describe it as tightly coupled to the RPC system.

That said, I wouldn't recommend it for new projects.