Because Java's native character set is Unicode, you may be surprised when many Java user interface components don't display characters correctly. Instead of seeing ???, you see ???. So, what's wrong here? Java is supposed to display these characters, right? The answer is yes, maybe. Correct character display often depends on a little known and less understood file called font.properties. If you've installed Sun's Java Development Kit, you have this file. If you use a web browser, you have this file. Having a properly configured font.properties file can make all the difference in whether you see multilingual text or mangled gibberish in your Java application.

Java's font.properties file is platform dependent. That means that its contents will be different depending on your operating system (OS). However, the basic structure and purpose will remain the same. Since the file must be configured for a specific OS, this article will describe the file on a Windows 98 and Windows NT 4.0 system. Don't let the choice of OS frustrate you or discourage you from reading further; you should be able to apply the concepts to your own file whether you use Mac OS, Solaris, Linux, or something else entirely different.