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?

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

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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.