ERRO [com.mysql.jdbc.Driver] but failed

org.apache.catalina.loader.WebappClassLoaderBase- The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
2016-11-22 16:18:01,423 [localhost-startStop-2] ERROR org.apache.catalina.loader.WebappClassLoaderBase- The web application [] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.