I'm coming to Java from C# & ASP.NET MVC, I'd love to find an equivalent in the Java world that I could use on the Google App Engine. I've already started to have a play with FreeMarker and even made the first steps towards writing a very simple framework. Ideally I wouldn't have to do all the hard work though, someone must have done this already! So my question is - what frameworks are there out there that would be familiar for me coming from ASP.NET MVC and I could use them on Google App Engine for Java.

The key things I'd want are:

• Simple Routing - /products/view/1 gets mapped to the view action of the products controller with the productid of 1
• Template Engine - some way of easily passing 'ViewData' to the view, and from the view easily accessing it, ideally I'd love to avoid anything that is too XMLy (thus why I like FreeMarker).