Applet doesn't work with Windows XP - Netscape 4.x

Question

All - I have a Java web application which is supported for Windows 2000. Users are required to use Netscape 4.x. It uses a Swing JApplet. A plug-in is not required for Netscape, but there are some supporting JAR files installed on the client to enable the Swing components. It works fine on Windows 2K, but it breaks on Windows XP. More specifically, it throws an Exception:
java.lang.NoClassDefFoundError: com/sun/java/swing/Japplet
Does anybody have any thoughts as to why it works for Windows 2K but won't load the JApplet for Windows XP?
Thanks

Answer 1

Hi,
I'm assuming that if your users must use Netscape 4x, (without the plugin), then 1) they are using the built-in version of Java (1.1.5), and 2), the Java 1.1 swingall.jar file, is placed in the user's Netscape classes directory?
If that's true, then you probably want to make sure you are using the same version of the Java 1.1 swingall.jar on both the Windows 2000 and on the XP machines. When Sun was first working on Swing, each beta version had a different package placement for the swing classes. One version placed the classes in com.sun.java.swing, but the final version placed the classes in javax.swing.
The JApplet you are trying to use is still referring to the package name used in that beta version of Swing. If you try to download a current version of the Java 1.1 swing runtime, for installation on your XP machines, however, the swingall.jar will not have the classes in those locations.
--Steve