Xml-based User Interface Description Language And Related Issues

Along with the development of the computer technologies, GUI (Graphic User Interface) has great progress. One of these GUI technologies is the thin-client. Thin-client technology has a smallest GUI element set, that can simplify the work of describing UI. However, the limitation of GUI element set makes the user difficult to construct complex GUI with thin-client.To overcome the shortcoming of thin-client, the rich client technology emerged. The rich client technology enlarges the GUI element set by adding some GUI elements that are difficult to be presented by the thin-client. Rich client is able to present rich content including text, graphics and multimedia, even beyond all of these. Rich client is hot technology that attracts the focus from many organizations and individuals.This article shows the JUDL based on JFC (Java Foundation Classes). JUDL stands for Java User Interface Description Language. It builds a describing methodology based on the rich client technology of the JFC, and it employs XML (Extensible Markup Language) and some special techniques such as local and remote event model, and DOM GUI binding to promote the interaction between the GUI and application logic. JUDL try to solve problems in 2 categories, the first is GUI is built from Java codes that are hard to maintain; the second is the HTML front ends of web applications have too much weak points such as monotony and slowness.This article also discusses the deployment of JUDL in J2EE applications. As an alternative of HTML, JUDL cannot replace directly in application. Some modification in architecture is needed. These problems are analyzed in this article.