1、maven环境配置如下：
2、运行时出现如下警示
13-Jul-2020 21:41:56.634 信息 [mysql-cj-abandoned-connection-cleanup] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading 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:1328)
at org.apache.catalina.loader.WebappClassLoaderBase.getResource(WebappClassLoaderBase.java:1003)
at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.checkThreadContextClassLoader(AbandonedConnectionCleanupThread.java:117)
at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:84)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
3、window10安装的是MySQL8.0.20，虽不影响使用，可MySQL5.7到8.0版本更替出现这样的问题，心里不踏实。
