If the “Web 2.0” presentation layer of your Java Web application has an international audience, you can’t rely on the user’s browser to intuitively display the appropriate language. Locale-sensitive methods in JavaScript perform formatting based on the default locale of the browser. This value may not necessarily match the locale of the user’s PC because the browser locale is tied to the browser’s build version.
That’s why most international websites offer visitors the option of selecting their preferred language and/or country, tailoring their experiences to their particular tastes. In his WebReference.com article, Rob Gravelle explains how to implement multilingual support to your Web pages and client-side scripts using Java Servlets and JSPs.