在我的 Web 开发过程中,我刚刚在 Eclipse IDE 中关闭了我的 Web 应用程序,大约一分钟,我刚刚在 Eclipse 控制台中看到了一个警告。
WARNING: The web application [/Spring.MVC] 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.
Sep 06, 2014 8:31:55 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
WARNING: The web application [/Spring.MVC] 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(Unknown Source)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:40)
Sep 06, 2014 8:32:00 PM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Sep 06, 2014 8:32:00 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
Sep 06, 2014 8:32:03 PM org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformation
INFO: HHH000204: Processing PersistenceUnitInfo [
name: personPU
...]
到目前为止,它没有造成任何内存泄漏,我检查了我的VisualVM,一切都正常工作,但是当我更多地搜索这件事时,我意识到这个警告是由MySQL驱动程序没有释放资源或没有正确关闭引起的(我不知道该怎么准确地说)我最终在这篇文章中找到了SO相关问题
OP是对的“别担心”的答案是不够的。这个警告让我很困扰,因为它可能会给我带来一些“未来的持久性问题”,这让我很担心,我尝试了OP编写的代码,但我遇到了一个问题“我应该使用什么库”来使该代码工作。这就是我到目前为止所得到的..
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Enumeration;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import org.hibernate.annotations.common.util.impl.LoggerFactory;
import com.mysql.jdbc.AbandonedConnectionCleanupThread;
@WebListener
public class ContextFinalizer implements ServletContextListener {
private static final Logger LOGGER = LoggerFactory.getLogger(ContextFinalizer.class);
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);
LOGGER.warn(String.format("Driver %s deregistered", d));
}
catch (SQLException ex) {
LOGGER.warn(String.format("Error deregistering driver %s", d), ex);
}
}
try {
AbandonedConnectionCleanupThread.shutdown();
}
catch (InterruptedException e) {
logger.warn("SEVERE problem cleaning up: " + e.getMessage());
e.printStackTrace();
}
}
}
我只是想知道我需要什么库,或者如果我使用正确的库来正确实现这一点,我什至不知道我应该使用什么记录器,谢谢您的帮助,
请参阅
此答案systemctl 状态 tomcat10.service
PS。我使用的是 Debian 操作系统、MariaDb 和 Tomcat10。 希望这可以帮助你。
这对我有用
。
从邮递员发送DELETE请求到以下端点并重新启动您的应用程序。
{$TOMCAT]/lib