well I think you have to decide a working model by between you and your java guys.As you know and probably what your trying to do, you make almost make the browser work like client-server model (not that they are not, just not so clearly i guess). If you want do all the display and UI logic by javascript, then all you need is probably the "data" that you need to display. Then you can just tell the java guys to serve you data only, maybe except when you load the first page of course, so you can keep your url consistent.
And just to make sure you know. "servlet" is main thing that java use for web applications. so dont be scared to talk about servlet. But the important thing is what's the data and the format of the data generated BY THE servlets. In my project, I have servlets delivering jsp generated HTML and JSON formated text depending on the situation. I believe you can do that as well. Just that the java guys may want some kind of organization within themselves to separate the different kind of output and thats something you dont need to know.
