[FIXED] How can i solve java.lang.IllegalStateException: Illegal access:?

Issue

I am using Eclipse to develope a webapp. Everything was working fine, but sometimes when I tried to publist->start my server, I received the following error:

Oct 03, 2019 6:52:55 PM org.apache.catalina.loader.WebappClassLoaderBase checkStateForResourceLoading
INFO: Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1383)
    at org.apache.catalina.loader.WebappClassLoaderBase.getResource(WebappClassLoaderBase.java:1036)
    at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.checkThreadContextClassLoader(AbandonedConnectionCleanupThread.java:117)
    at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:84)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)

For the first few times, I just restarted the server, and it was working fine, but now even a restart doesent solve the problem. I read about it online, and some sources mentioned that it might be a thread management issue, but I couldn't get further than that. Can anybody please provide some info? Thanks.

Solution

The mysql driver is trying to clean-up on web application shutdown which is good. Unfortunately it is trying to load additional classes to perform this clean-up and - since the web application is shutting down - class loading is no longer available. Ideally, the driver would load all the classes it needed to clean-up when it firsts loads - that would avoid this issue.

If you can figure out which classes it is trying to load - a check of the driver source code should show you which - then you should be able to load them yourself on application start in, for example, a ServletContextListener.

Answered By - Mark Thomas