报错信息
21-Aug- 11:05:58.506 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc Web应用程序 [ROOT] 注册了JDBC驱动程序 [com.mysql.cj.jdbc.Driver],但在Web应用程序停止时无法注销它。 为防止内存泄漏,JDBC驱动程序已被强制取消注册。21-Aug- 11:05:58.507 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads Web应用程序[ROOT]似乎启动了一个名为[Timer-0]的线程,但未能停止它。这很可能会造成内存泄漏。线程的堆栈跟踪:[java.lang.Object.wait(Native Method)java.util.TimerThread.mainLoop(Timer.java:552)java.util.TimerThread.run(Timer.java:505)]21-Aug- 11:05:58.508 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads Web应用程序[ROOT]似乎启动了一个名为[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0]的线程,但未能停止它。这很可能会造成内存泄漏。线程的堆栈跟踪:[java.lang.Object.wait(Native Method)com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)]21-Aug- 11:05:58.508 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads Web应用程序[ROOT]似乎启动了一个名为[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1]的线程,但未能停止它。这很可能会造成内存泄漏。线程的堆栈跟踪:[java.lang.Object.wait(Native Method)com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)]21-Aug- 11:05:58.509 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads Web应用程序[ROOT]似乎启动了一个名为[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2]的线程,但未能停止它。这很可能会造成内存泄漏。线程的堆栈跟踪:[java.lang.Object.wait(Native Method)com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)]21-Aug- 11:05:58.509 警告 [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads Web应用程序[ROOT]似乎启动了一个名为[Abandoned connection cleanup thread]的线程,但未能停止它。这很可能会造成内存泄漏。线程的堆栈跟踪:[java.lang.Object.wait(Native Method)java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)]21-Aug- 11:05:58.525 信息 [main] org.apache.coyote.AbstractProtocol.stop 正在停止ProtocolHandler ["http-nio-8080"]21-Aug- 11:05:58.528 信息 [main] org.apache.coyote.AbstractProtocol.destroy 正在摧毁协议处理器 ["http-nio-8080"]Disconnected from server
解决方法
一、tomcat服务器关闭后,jdbc驱动程序不会与web应用程序同步停止,需要手动注销程序。可以编写ContextFinalizer类
package cn.itcast.tools;import com.mysql.cj.jdbc.AbandonedConnectionCleanupThread;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;import javax.servlet.annotation.WebListener;import java.sql.Driver;import java.sql.DriverManager;import java.sql.SQLException;import java.util.Enumeration;@WebListenerpublic class ContextFinalizer implements ServletContextListener {public void contextInitialized(ServletContextEvent sce) {}public void contextDestroyed(ServletContextEvent sce) {Enumeration<Driver> drivers = DriverManager.getDrivers();Driver d = null;while (drivers.hasMoreElements()) {try {d = drivers.nextElement();DriverManager.deregisterDriver(d);System.out.println(String.format("ContextFinalizer:Driver %s deregistered", d));} catch (SQLException ex) {System.out.println(String.format("ContextFinalizer:Error deregistering driver %s", d) + ":" + ex);}}try {AbandonedConnectionCleanupThread.shutdown();} catch (InterruptedException e) {System.out.println("ContextFinalizer:SEVERE problem cleaning up: " + e.getMessage());e.printStackTrace();}}}
在web.xml中配置监听器
<listener><listener-class>cn.itcast.tools.ContextFinalizer</listener-class></listener>
二、c3p0连接池线程的关闭
在配置文件中加入销毁方法
<bean id="dataSource" class="com.mchange.boPooledDataSource" destroy-method="close">