What JS framework to use with JavaEE?

Just thinking about to learn some JavaScript framework (ember/backbone preferred) along with JavaEE while creating a real time chat application (something like git mattermost, but much more easier: http://ift.tt/1Q1qPxs)

I have decided to use JavaEE-7 with it's websockets, the Java already has JSF technology built in, will JSF work well with framework such as ember or backbone? Or is there more suitable JS framework to use for creating app like this?