IDEA 在关闭 tomcat 时报错 memory leak 与 Failed to destroy connector

Question

/Library/apache-tomcat-8.5.29/bin/catalina.sh stop 25-Mar-2018 10:37:27.822 ?? [main] org.apache.catalina.core.StandardServer.await A valid shutdown command was received via the shutdown port. Stopping the Server instance. 25-Mar-2018 10:37:27.822 ?? [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["http-nio-8080"] 25-Mar-2018 10:37:27.825 ?? [main] org.apache.coyote.AbstractProtocol.pause Pausing ProtocolHandler ["ajp-nio-8009"] 25-Mar-2018 10:37:27.827 ?? [main] org.apache.catalina.core.StandardService.stopInternal Stopping service [Catalina] 25-Mar-2018 10:37:27.829 ?? [localhost-startStop-2] org.springframework.web.context.support.XmlWebApplicationContext.doClose Closing WebApplicationContext for namespace 'springMVC-servlet': startup date [Sun Mar 25 10:37:09 CST 2018]; root of context hierarchy 25-Mar-2018 10:37:27.835 ?? [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [ROOT] 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. 25-Mar-2018 10:37:27.836 ?? [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [ROOT] 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. Stack trace of thread: java.lang.Object.wait(Native Method) java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143) com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43) 25-Mar-2018 10:37:27.847 ?? [main] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["http-nio-8080"] 25-Mar-2018 10:37:27.853 ?? [main] org.apache.coyote.AbstractProtocol.stop Stopping ProtocolHandler ["ajp-nio-8009"] 25-Mar-2018 10:37:27.854 ?? [main] org.apache.coyote.AbstractProtocol.destroy Destroying ProtocolHandler ["http-nio-8080"] 25-Mar-2018 10:37:27.856 ?? [main] org.apache.catalina.core.StandardService.destroyInternal Failed to destroy connector [Connector[HTTP/1.1-8080]] org.apache.catalina.LifecycleException: Failed to destroy component [Connector[HTTP/1.1-8080]] at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:302) at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:571) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:883) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) at org.apache.catalina.startup.Catalina.stop(Catalina.java:755) at org.apache.catalina.startup.Catalina.start(Catalina.java:716) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:353) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:493) Caused by: org.apache.catalina.LifecycleException: Protocol handler destroy failed at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1050) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:297) ... 12 more Caused by: java.io.IOException: Thread signal failed at sun.nio.ch.NativeThread.signal(Native Method) at sun.nio.ch.ServerSocketChannelImpl.implCloseSelectableChannel(ServerSocketChannelImpl.java:292) at java.nio.channels.spi.AbstractSelectableChannel.implCloseChannel(AbstractSelectableChannel.java:234) at java.nio.channels.spi.AbstractInterruptibleChannel.close(AbstractInterruptibleChannel.java:115) at sun.nio.ch.ServerSocketAdaptor.close(ServerSocketAdaptor.java:137) at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:313) at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:1210) at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:647) at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1048) ... 13 more 这个项目就只是用来学习 SSM 的，里面只写了查询表中所有记录的代码。求教为啥会出现这些错误呢？