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https://issues.apache.org/jira/browse/BEANUTILS-566?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17873273#comment-17873273
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Volodymyr Siedlecki commented on BEANUTILS-566:
-----------------------------------------------
Appreciate any feedback (either to the fix or the test code) if anyone has
time. Thanks again.
> Classloader Out-Of-Memory Error: Server-Provided BeanUtils and
> Application-Provided Logger
> ------------------------------------------------------------------------------------------
>
> Key: BEANUTILS-566
> URL: https://issues.apache.org/jira/browse/BEANUTILS-566
> Project: Commons BeanUtils
> Issue Type: Bug
> Affects Versions: 1.9.4
> Reporter: Volodymyr Siedlecki
> Priority: Major
>
> Hello,
> We have a classloader leak occurring in WebSphere. The server provides
> BeanUtils (used by JSF) while the application provides it's own Logger
> (SLF4J). This configuration causes eventually causes a leak. We've tried
> other ways to solve this leak, but the only working solution has been to
> update the BeanUtil code.
> *Explanation of the leak:*
> In a server-level class (in this case, BeanUtilsBean) has a reference to a
> class loaded by an application class loader (SLF4JLocationAwareLog). This is
> generally fine... until the application is stopped. When the application
> stops, its class loader is "disposed" (we clear out its internal class path
> and some other references) and ideally should be eligible for garbage
> collection, but the reference to one of its classes prevents that. The chain
> below shows BeanUtilsBean -> SLF4JLocationAwareLog -> SLF4JLocationAwareLog's
> class loader (the CompoundClassLoader), and that class loader cannot be GC'd
> unless the reference to that application copy of SLF4JLocationAwareLog is
> cleared.
>
> {code:java}
> com.ibm.ws.classloader.CompoundClassLoader @ 0x9a708520
> war:CustomerApp/App.war
> '- <classloader>, <classLoader> class
> org.apache.commons.logging.impl.SLF4JLocationAwareLog @ 0xb0074658
> '- <class> org.apache.commons.logging.impl.SLF4JLocationAwareLog @
> 0xb15557e8
> '- log org.apache.commons.beanutils.BeanUtilsBean @ 0xb1538560
> '- value java.util.WeakHashMap$Entry @ 0xb1537e78 war:CustomerApp/App.war
> {code}
> *Proposed Fix:*
> By using the context class loader for logger instantiation, this leak can be
> easily resolved via the code below. (albeit applied to every logger
> instance). Perhaps it could be hidden behind a JVM property, if applied?
>
> {code:java}
> private final Log log = getLoggerWithCorrectClassLoader();public Log
> getLoggerWithContextClassLoader() {
> java.lang.ClassLoader currentCL =
> Thread.currentThread().getContextClassLoader();
> Log log = null;
> try {
>
> Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
> log = LogFactory.getLog(getClass());
> } finally {
> Thread.currentThread().setContextClassLoader(currentCL);
> }
> return log;
> }{code}
>
> I see there are other issues open relating to updating the loggers
> –https://issues.apache.org/jira/browse/BEANUTILS-562
> Perhaps this could also be considered. Thanks!
>
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