There are cases when you want to convert your existing web tier to an AJAX friendly one for the benefit of presenting a more responsive visual interface to your users. Just to remind you, that with AJAX, the user browser updates or refreshes only partially with any user actions. To lower the cost and spend as less as possible on the task, I adopted recently a technique that proved to be fast and to work as expected. Please find the complete description at Make a J2EE web application AJAX friendly

very interesting :) to confirm does that means we need to insert the onclick custom Javascript and mark the content and navigation bar with (DIV)to all pages? and also by doing this all the normal flow is still preserved but being filtered by JAXPostProcessingFilter right? very good way to change the ajax way in a short term.

I have just opened a opensource project on sourceforge at: http://sourceforge.net/projects/ajax4j2ee/ and published code for the 0.1 release and a wiki. Both are work in progress though. To reply to the only comment I have received so far, I am going to provide support for navigation history too for page that are AJAXisified by applying one of the tips I've read in 'AJAX Hacks. Tips & Tools for Creating Responsive Web Sites' by Bruce W. Perry