Groovy / Grails is a great thing, as for me too. You get a JVM and a whole lot of Java Libraries accessible from Groovy code, but also dynamic typing and, more or less, lightweight framework. That's if you're already familiar with Java. I think that it's going to be pretty easy for you. There're way more things laying around, such as JRuby that runs on JVM. But that all highly depends on what you're going to develop, or what tools you're most familiar with...
My personal bias is to stay away from frameworks and use JDBC and a text templating library.
I would also stay away from most frameworks. Both the Play and Wicket groups have posts from people wondering where their memory has gone to.
1.how do you set Nginex to foreword to the servlet container in Apache i used mod_jk
2.what are text templating ?
3.what are Play and Wicket groups?
4.is jetty really better then tomcat?
I usually create a Javascript file per-page that is outside of the frameworks that I call "pagename"_controller.js I put all of the controller code in this file and general make it procedural. So this file will put widgets on the page, glue communication between widgets, and generally act as the view controller for that page.
The controllers as wells as the server side services, I generally develop internally, because they require the most application knowledge. But if it is a huge product, I usually define the requirements for the widgets and sub them out.
The nice part is in the end, the pages are pure HTML, CSS and all of the Javascript is external to the HTML and CSS so it allows the designers to work in a pure technology that they are comfortable with. It also allows me to sub out work very easily because all of the technologies are well encapsulated. I can sub out a widget by just defining the requirements for that widget and the input and output calls. They do not need to understand the whole system rather just their box. As well my designers are able to take those widgets and drop them on the page and I am able to wire it all up. It is very clean, while maintaining the ability to rapidly develop and application.
Finally, I use JAX-RS and JPA to build server side services. This part is pretty straight forward as JAX-RS provides all of the marshaling and unmarshaling of objects as well as all of the web API's for things like grabbing cookies and security.
"...CMS to do all of my static page templating and export them out as static pages .."
which CMS can do that?
does using XMLhttp or other Ajax methods submitting json have preformants problem ? i mean isn't better to use simple requests?
Edit: I should also add that JSF 2.0 makes ajax simple.