I have quite extensive Java experience (many years of Swing, desktop apps, gigantic applets), but have done very little JEE - only one single gig for 9 months, but that was very narrow work where I was basically just implementing business logic (in a highly abstracted internal company IDE) and at most tweaking some JSP pages. Never really picked up the macro flow of the JEE framework in depth.
In the meantime, I've done some very limited maintenance of an ASP.NET MVC app at my previous job (very limited) and am currently playing around with Ruby on Rails at home. I feel like I have the basic gist of web development down, but nothing that I can call solid "industrial strength experience" with any of these frameworks. I'm still a bit in the "cargo cult programming" stage with web development, can't really say that I could plug leaks in the abstractions if they broke, so to speak.
So what I'm wondering is: with this background (extensive Java and a decent grasp of how web frameworks work), is JEE going to be be relatively logical and easy to pick up, or will it be a huge and steep learning curve?
Basically, I'm planning to learn it, and want a preliminary idea about how big an effort it's going to be.