How to debug/log/trace an applet loading problem?

Question

Recently two of our clients have reported problems with our applets. Looking at the java plugin console it is full of ClassNotFoundException so none of our code is executed.

I've been able to reproduce the stack trace using a virtual pc image with 0 free space on disk, but the problem goes away as I restore some disk space, and the users tell me that their disk is not full; they are able to create new files.

Our applet requires java 6, and the problem has appeared with updates 1, 10 and 14 of the jre. We have also tried different browsers (IE and Firefox), clearing the browser and java caches, ...

How can I debug or trace what is the jvm doing to load our applet?

I suppose that the problem lies on some security directive on windows so I'm using Sysinternal's Process Monitor to log the activity but I don't really know where to look at.

Answer 1

The Java cache is most likely messed up. Open Java in the Control Panel and get rid of all temporary files to see if it goes away.

Logging in the Java Console for loading applets can be enabled which helps quite alot (even if the plugin is extremely cryptic). See http://java.sun.com/javase/6/docs/technotes/guides/deployment/deployment-guide/tracing_logging.html