In an OSGi environment, the best ClassLoader to use for something in log4j-core is one obtained from a class in log4j-core. Come to think of it, it'd be better to do something like this:
LoggerContext.class.getClassLoader().loadClass(...); On 6 December 2016 at 22:39, Gary Gregory <garydgreg...@gmail.com> wrote: > I think one of the points here is that a class is loaded from a specific > class loader. This is not clear from the code or comments. I am not sure > this 100% correct either but if that fixes at least the null class loader > NPE then that is a good thing. Especially if the fix is less hacky than > inially proposed. I am open to better comments and code ;-) > > Gary > > > On Dec 6, 2016 8:24 PM, "Matt Sicker" <boa...@gmail.com> wrote: > > I'm not sure if that LoaderUtil line will work properly everywhere. You > already implicitly load the class by referencing the class's .class > property I think. Either way, a more amusing and surefire way to make it > load would be: > > ExecutorServices.class.getClassLoader().loadClass(ExecutorSe > rvices.class.getName()); > > Or use one of the LoaderUtil/Loader methods that takes a ClassLoader > argument to avoid an NPE if log4j is loaded as a bootstrap class somehow. > > ---------- Forwarded message ---------- > From: <ggreg...@apache.org> > Date: 6 December 2016 at 18:07 > Subject: logging-log4j2 git commit: [LOG4J2-1642] > To: comm...@logging.apache.org > > > Repository: logging-log4j2 > Updated Branches: > refs/heads/master 2eb02c827 -> bdac7f223 > > > [LOG4J2-1642] > > DefaultShutdownCallbackRegistry can throw a NoClassDefFoundError. > > Project: http://git-wip-us.apache.org/repos/asf/logging-log4j2/repo > Commit: http://git-wip-us.apache.org/repos/asf/logging-log4j2/commit > /bdac7f22 > Tree: http://git-wip-us.apache.org/repos/asf/logging-log4j2/tree/bdac7f22 > Diff: http://git-wip-us.apache.org/repos/asf/logging-log4j2/diff/bdac7f22 > > Branch: refs/heads/master > Commit: bdac7f223b41dfbbf204ca924d08e6ed86c76769 > Parents: 2eb02c8 > Author: Johno Crawford <jo...@sulake.com> > Authored: Tue Dec 6 16:07:52 2016 -0800 > Committer: Gary Gregory <garydgreg...@gmail.com> > Committed: Tue Dec 6 16:07:52 2016 -0800 > > ---------------------------------------------------------------------- > .../apache/logging/log4j/core/LoggerContext.java | 16 +++++++++++++--- > .../core/util/DefaultShutdownCallbackRegistry.java | 9 +++++++-- > src/changes/changes.xml | 3 +++ > 3 files changed, 23 insertions(+), 5 deletions(-) > ---------------------------------------------------------------------- > > > http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b > dac7f22/log4j-core/src/main/java/org/apache/logging/log4j/co > re/LoggerContext.java > ---------------------------------------------------------------------- > diff --git > a/log4j-core/src/main/java/org/apache/logging/log4j/core/LoggerContext.java > b/log4j-core/src/main/java/org/apache/logging/log4j/core/Log > gerContext.java > index 6902ade..4c4845e 100644 > --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/Log > gerContext.java > +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/Log > gerContext.java > @@ -16,6 +16,8 @@ > */ > package org.apache.logging.log4j.core; > > +import static org.apache.logging.log4j.core. > util.ShutdownCallbackRegistry.SHUTDOWN_HOOK_MARKER; > + > import java.beans.PropertyChangeEvent; > import java.beans.PropertyChangeListener; > import java.io.File; > @@ -52,10 +54,9 @@ import org.apache.logging.log4j.spi.AbstractLogger; > import org.apache.logging.log4j.spi.LoggerContextFactory; > import org.apache.logging.log4j.spi.LoggerRegistry; > import org.apache.logging.log4j.spi.Terminable; > +import org.apache.logging.log4j.util.LoaderUtil; > import org.apache.logging.log4j.util.PropertiesUtil; > > -import static org.apache.logging.log4j.core. > util.ShutdownCallbackRegistry.SHUTDOWN_HOOK_MARKER; > - > /** > * The LoggerContext is the anchor for the logging system. It maintains a > list of all the loggers requested by > * applications and a reference to the Configuration. The Configuration > will contain the configured loggers, appenders, > @@ -63,7 +64,16 @@ import static org.apache.logging.log4j.core. > util.ShutdownCallbackRegistry.SHUTDO > */ > public class LoggerContext extends AbstractLifeCycle > implements org.apache.logging.log4j.spi.LoggerContext, > AutoCloseable, Terminable, ConfigurationListener { > - > + > + static { > + try { > + // LOG4J2-1642 preload ExecutorServices as it is used in > shutdown hook > + LoaderUtil.loadClass(ExecutorServices.class.getName()); > + } catch (final Exception e) { > + LOGGER.error("Failed to preload ExecutorServices class.", e); > + } > + } > + > /** > * Property name of the property change event fired if the > configuration is changed. > */ > > http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b > dac7f22/log4j-core/src/main/java/org/apache/logging/log4j/co > re/util/DefaultShutdownCallbackRegistry.java > ---------------------------------------------------------------------- > diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/uti > l/DefaultShutdownCallbackRegistry.java b/log4j-core/src/main/java/org > /apache/logging/log4j/core/util/DefaultShutdownCallbackRegistry.java > index 48d54b6..d2be690 100644 > --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/uti > l/DefaultShutdownCallbackRegistry.java > +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/uti > l/DefaultShutdownCallbackRegistry.java > @@ -72,8 +72,13 @@ public class DefaultShutdownCallbackRegistry > implements ShutdownCallbackRegistry > for (final Runnable hook : hooks) { > try { > hook.run(); > - } catch (final Throwable t) { > - LOGGER.error(SHUTDOWN_HOOK_MARKER, "Caught exception > executing shutdown hook {}", hook, t); > + } catch (final Throwable t1) { > + try { > + LOGGER.error(SHUTDOWN_HOOK_MARKER, "Caught > exception executing shutdown hook {}", hook, t1); > + } catch (final Throwable t2) { > + System.err.println("Caught exception logging > exception"); > + t1.printStackTrace(); > + } > } > } > state.set(State.STOPPED); > > http://git-wip-us.apache.org/repos/asf/logging-log4j2/blob/b > dac7f22/src/changes/changes.xml > ---------------------------------------------------------------------- > diff --git a/src/changes/changes.xml b/src/changes/changes.xml > index a6279b2..4fa7e54 100644 > --- a/src/changes/changes.xml > +++ b/src/changes/changes.xml > @@ -147,6 +147,9 @@ > <action issue="LOG4J2-1687" dev="ggregory" type="fix" > due-to="Robert Christiansen"> > NPE in ThrowableProxy when resolving stack in Java EE/OSGi > environment. > </action> > + <action issue="LOG4J2-1642" dev="ggregory" type="fix" due-to="Johno > Crawford"> > + DefaultShutdownCallbackRegistry can throw a NoClassDefFoundError. > + </action> > <action issue="LOG4J2-1644" dev="ggregory" type="update" > due-to="Tim Gokcen, Pavel Sivolobtchik"> > Inefficient locking in AbstractLoggerAdapter. > </action> > > > > > -- > Matt Sicker <boa...@gmail.com> > > > -- Matt Sicker <boa...@gmail.com>
