Okay, it’s official. Now everybody has a web 2.0 solution.
With GWT, you can develop and debug AJAX applications in the Java language using the Java development tools of your choice. When you deploy your application to production, the GWT compiler to translates your Java application to browser-compliant JavaScript and HTML.
Google Web Toolkit – Product Overview
Haven’t tried it, but it looks like it would work. Of course, the devil is in the details 🙂
Myself, I’ve been using prototype and scriptaculous "raw" (just some JSP tags of my own here and there) on my web application pretty successfully. Remember, in scriptable languages, testing is key.
You also learn a lot from reading their source code. But if you are source code illiterate (what a handicap for a programmer!) a cheatsheet or documentation can help.