If you work with development of some sort, big chances are you work with web development.
I have gone through this myself as I have seen colleagues going through this too.
For that I recommend Jasmine, have been using it in our project, love it.
There’s plenty of good websites and books out there for you to learn it, so go on and have fun!
You could go with GWT for instance. And I remember there were other frameworks that let you develop the whole fancy UI on Java on the server side, sending only few instructions to the client – I can’t recall any names right now.
The thing is: is it worth it?