内存泄漏异常

Question

任何人都可以帮助我这个例外：

Jul 23, 2012 11:00:57 AM org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.  Could not load com.mchange.v2.sql.SqlUtils.  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:1597)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:531)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
    at org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:78)
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142)
    at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85)
    at net.customware.gwt.dispatch.server.AbstractDispatch.doExecute(AbstractDispatch.java:81)
    at net.customware.gwt.dispatch.server.AbstractDispatch.execute(AbstractDispatch.java:68)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:216)
    at com.google.inject.servlet.ServletDefinition.service(ServletDefinition.java:141)
    at com.google.inject.servlet.ManagedServletPipeline.service(ManagedServletPipeline.java:93)
    at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:63)
    at com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:122)
    at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:110)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

.

还为其提供了可能的解决方案..？

提前感谢...

Answer 1

基本问题是Tomcat为每个webapp创建一个新的classloader，并在重置应用程序时禁用ClassLoader，例如，通过热部署新版本。 C3P0创建辅助线程。如果C3P0已在Web应用程序的类加载器中加载，则该应用程序被重置，C3P0的线程仍可能会实现，并且仍然可以实现对来自现在已缺失的ClassLoader的对象的引用，导致您在新的类必须何时看到的错误类型加载。

多线程组件与Tomcat的“热”类负载方案之间的交互可能是具有挑战性的。一些建议：

1）如果您的web应用程序构造自己的c3p0 dataSource（例如，在ContextListener中），请确保在将应用程序关闭时（在同一ContextListener）中时，数据源也关闭（）ed（）ed

2）尝试使用C3P0和您的JDBC驱动程序类以Web应用程序特定的类加载器以外的其他内容加载。将C3P0 jar文件，Change-Commons-Java jar文件，以及您的JDBC驱动程序JAR文件，其中常见的，系统或Bootstrap ClassLoader将找到它。请务必将这些文件从WebApp的lib目录中取出，因为首先尝试Web App ClassLoader。查看 http://tomcat.apache.org/tomcat-6.0- doc / class-loader-howto.html 更多。

我希望这有助于！