In this article, Joel Confino explains how existing web pages can be augmented to make use of AJAX by using jQuery, a JavaScript library. He also shows how to retrieve data as XML instead of HTML by using Spring with XStream/Jettison.
Read: Your First Cup of Web 2.0 - A Quick Look at jQuery, Spring MVC, and XStream/Jettison
Many web pages use AJAX to connect to the server in order to bring new data to be displayed without refreshing the entire page. The constant page refresh is annoying for the user, so it is desirable to be avoided. But there are still many older sites/pages which still refresh the page when data is requested, or the user clicks a button. Updating all those pages to use AJAX can be a time consuming task. Using jQuery, the developer can transform existing pages to use AJAX with little coding.
In his article, Joel explains how to use jQuery on the client, and he also shows how to return data as XML instead of HTML by using Spring with XStream/Jettison, which can improve how portions of a page are refreshed, making the pages more responsive and avoiding the annoying page refresh.