Abandoned connection cleanup thread failed to stop

问题：

 A 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.

解决：

1. 升级mysql-connector-java版本。

2. 引入:

@Component
public class ShutdownListener implements ServletContextListener {
    @Overridepublic void contextInitialized(ServletContextEvent sce) {
    }@Overridepublic void contextDestroyed(ServletContextEvent sce) {
    AbandonedConnectionCleanupThread.checkedShutdown();}
}

参考：https://bugs.mysql.com/bug.php?id=69526