mysql - c3p0 - hibernate - mysql

Question

• hibernate 3.6.8 最终版本

• hibernate 3.6.8 包附带的 c3p0 jar -> c3p0-0.9.1.jar

  1个154005个2

该应用程序似乎运行良好，但我收到大量带有以下堆栈跟踪的日志调用:

org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.  Could not load com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1566)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2411)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.GeneratedConstructorAccessor38.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:152)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1074)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1061)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1796)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:620)

有关如何删除该 INFO 日志的任何信息都会非常有帮助，谢谢!

更新:这是严重错误吗？或者我应该忽略它吗？

Answer 1

在网上搜索有关此问题的信息后，我发现有几个人报告了一些类似的问题。所有这些都指向一个共同的问题:线程。基本上，如果您在应用程序中启动新线程(无论是在您的代码中还是通过使用像 Quartz 这样的第三方工具，您必须确保在取消部署应用程序时适本地停止所有线程来自服务器。以下是搜索中的一些引述:

Mikolaj Rydzewski wrote :

It looks like after webapp's instance has been undeployed, background quartz thread wants to do something and then exception occurs.

关于 jspwiki.org 的另一个(更好的解释) :

It is possible that this is caused by Tomcat unsuccessfully reloading the web application. The app is unloaded, but all threads don't get shut down properly. As a result, when the threads try to run, they get clobbered by the fact that Tomcat has shut down its classloader, and an error is logged.

因此，为了解决这个问题，您必须确保应用程序启动的所有线程都将在应用程序取消部署(或重新部署，都是一样的)时停止。您可以通过向您的应用程序服务器注册一个 ServletContextListener 并在 contextDestroyed(ServletContextEvent) 方法中停止您的线程来做到这一点。