How to unload Dll in java?

I have written a Java agent in Lotus Notes 8.5 to reset token's PIN using IAIKPKCS11wrapper. When the agent is loaded for the first time it worked fine. But after I close and restart the agent then it failed. Checking the cons开发者_如何转开发ole output I discovered the following error:

Exception in thread "AgentThread: JavaAgent" java.lang.UnsatisfiedLinkError: pkcs11wrapper (Library is already loaded in another ClassLoader)

I have searched the group but the closest I could find is that it is not possible to unload the DLL library but I still have no idea how to handle it.

Can anyone point me the solution?

From one of the related SO questions, found this tutorial on DLL unloading.

Try adding the jar to your Lotus Notes classpath in notes.ini:

JavaUserClasses=...;yourAgent.jar

or copy your jar to the default Notes lib directory, which should be something like: C:\lotus\notes\jvm\lib\ext

Another thing to try is to put your dll in C:\lotus\notes.