That's a JDK "feature". You can't load a JNI library in more than one
classloader. That means if you try to load the .dll (or .so) with the
web-app loader, and then the application restarts (because you touched
the resin.conf or a .jar or a .class) the reloaded application will then
fail when it tries to load the JNI.


The easiest way to work around that is to put the class with the
System.loadLibrary in the global classpath, i.e. resin/lib, instead of
in WEB-INF/lib.