IDEA 在關(guān)閉 tomcat 時(shí)報(bào)錯(cuò) memory leak 與 Failed to destroy connector

/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

這個(gè)項(xiàng)目就只是用來(lái)學(xué)習(xí) SSM 的，里面只寫(xiě)了查詢表中所有記錄的代碼。求教為啥會(huì)出現(xiàn)這些錯(cuò)誤呢？

回答

編輯回答

枕邊人

首先這個(gè)問(wèn)題和Tomcat沒(méi)什么關(guān)系，從tomcat6版本開(kāi)始，增加了內(nèi)存泄露的驗(yàn)證。這種問(wèn)題是由于在jdbc4的驅(qū)動(dòng)加載的時(shí)候使用ServiceLoader進(jìn)行注冊(cè)，但是沒(méi)有進(jìn)行撤銷造成的。
可以手寫(xiě)一個(gè)ServletContextListener將驅(qū)動(dòng)撤銷。

public void contextDestroyed(ServletContextEvent contextEvent) {
    Enumeration<Driver> drivers = DriverManager.getDrivers();
        while (drivers.hasMoreElements()) {
            Driver driver = drivers.nextElement();
            try {
                DriverManager.deregisterDriver(driver);
                logger.info("deregistering jdbc driver: {}", driver);
            } catch (SQLException e) {
                logger.warn("Error deregistering driver {}", driver, e);
            }
        }
}

2017年11月9日 16:25