SEVERE: The web application [] registered the JDBC driver [com.alibaba.druid.proxy.DruidDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
SEVERE: 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.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-1] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-2] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-3] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-4] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-5] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-6] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-7] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-8] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-9] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [] appears to have started a thread named [startQuartz_Worker-10] but has failed to stop it. This is very likely to create a memory leak.
Jun 30, 2018 8:57:08 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: 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.
以上是tomcat報出的錯誤信息。
原因分析：通過查詢大量資料，同時結合自己的項目情況，分析得出引起tomcat memory leak 的原因有：
1、jdbc Driver在tomcat運行時進行註冊，但是當tomcat停止時沒有解除註冊;
2、使用quartz跑定時任務時，tomcat停了，quartz的線程沒有停掉；
3、web 容器重啓一個叫Abandoned connection cleanup thread的線程失敗.
解決辦法：
1、用腳本語言代替quartz的定時任務或將quartz與業務代碼剝離開來；
2、手動反註冊jdbc驅動，清理Abandoned connection cleanup thread。
import com.mysql.jdbc.AbandonedConnectionCleanupThread;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import java.sql.DriverManager;
import java.sql.SQLException;
/**
* Created by yinguo on 2018-06-26.
*/
public class QuartzContextListener implements ServletContextListener {
@Override
public void contextDestroyed(ServletContextEvent arg0) {
System.out.println("webService stop");
try {
while(DriverManager.getDrivers().hasMoreElements()) {
DriverManager.deregisterDriver(DriverManager.getDrivers().nextElement());
}
System.out.println("jdbc Driver close");
AbandonedConnectionCleanupThread.shutdown();
System.out.println("clean thread success");
} catch (SQLException e) {
e.printStackTrace();
}catch (InterruptedException e){
e.printStackTrace();
}
}
@Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("webService start");
}
} 最後再說一點，解決方案千篇一律，還是要具體問題具體分析！！！