Building dynamic applications in Java

Page reloading is a big hurdle in Web application development for Java developers.

Ajax is a Web application development method that uses code on the client machine to change data on the Web server. As a result, Web pages are dynamically updated without reloading the full page, interrupting data exchange. With Ajax, you can create richer, more dynamic user interfaces for Web applications that approach the speed and flexibility of applications running in the client side of your code.

Ajax is not a technology, it’s more than just a model – it’s a way to define and describe useful development techniques. Ajax is a new product in the sense that developers are just beginning to learn about it, even though all the components that run in an Ajax application were already created years ago. This boom is because the releases in 2004 and 2005 of several large and famous dynamic Web interfaces are based on Ajax technology, especially Google’s Gmail, Maps application and Flickr photo posting site. These interfaces are extremely innovative ideas that have been handled in “Web 2.0” by several developers, leading to a rapid increase in interest in Ajax applications.

An Improved Online Store
You can use Ajax to make traditional Web applications better by simplifying server-client interactions, limiting page reloads. To demonstrate this, I use a simple example of a shopping cart for an online store that dynamically updates when products are added to it. Applied to an online store, this technique could allow users to continue searching and adding products to their cart without waiting after each click to refresh the entire page. While some of the lines of code in this article are specific to the shopping cart example, the illustrated techniques can be applied to any Ajax application. Listing 1 shows the HTML code for the shopping cart example cases.