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ASF subversion and git services commented on LOG4J2-3040: --------------------------------------------------------- Commit 67ba1fe05951e20cb9c29b47a1b1e8a6d8e2e181 in logging-log4j2's branch refs/heads/dependabot/maven/org.apache.felix-maven-bundle-plugin-5.1.4 from Grzegorz Grzybek [ https://gitbox.apache.org/repos/asf?p=logging-log4j2.git;h=67ba1fe ] [LOG4J2-3040] Avoid ClassCastException in JeroMqManager with custom LoggerContextFactory (#791) Signed-off-by: Grzegorz Grzybek <gr.grzy...@gmail.com> > ShutdownCallbackRegistry should be part of log4j-api, not log4j-core > -------------------------------------------------------------------- > > Key: LOG4J2-3040 > URL: https://issues.apache.org/jira/browse/LOG4J2-3040 > Project: Log4j 2 > Issue Type: Bug > Reporter: Grzegorz Grzybek > Priority: Major > > I'm working on https://github.com/ops4j/org.ops4j.pax.logging/issues/395 > related to Pax Logging project, which implements OSGi Log specification based > on 3 _backends_: > * Log4j1 > * Logback > * Log4j2 > and several _frontends_: > * Commons Logging > * JULI Logging > * javax.logging > * SLF4J > * Avalong > * Log4j1 (API) > * Log4j2 (API) > * JBoss Logging > Pax Logging implements own > {{org.apache.logging.log4j.spi.LoggerContextFactory}}, where the > {{org.apache.logging.log4j.spi.LoggerContext}} returned is managed by OSGi > runtime (without using > {{org.apache.logging.log4j.core.selector.ContextSelector}}). > The problem is that several libraries assume that some casts are possible. > There was an elasticsearch problem described > [here|https://groups.google.com/g/ops4j/c/yjqOzvrKRkc/m/DZeUSdZeCAAJ], where > level was set through configuration and > {{org.apache.logging.log4j.core.LoggerContext#getContext(boolean)}} > explicitly calls (in > {{org.apache.logging.log4j.core.config.Configurator#setLevel()}}): > {code:java} > public static LoggerContext getContext(final boolean currentContext) { > return (org.apache.logging.log4j.core.LoggerContext) > LogManager.getContext(currentContext); > } > {code} > assuming that {{org.apache.logging.log4j.LogManager#getContext(boolean)}} > returns log4j-core specific implementation of the context. > With https://github.com/ops4j/org.ops4j.pax.logging/issues/395 there's > different problem. > {{org.apache.logging.log4j.core.appender.mom.jeromq.JeroMqAppender}} (part of > log4j-core library) [long time > ago|https://github.com/apache/logging-log4j2/commit/a6af67c5d6faee5b4d422add674e4c518c33d528] > started to use > {{org.apache.logging.log4j.core.util.ShutdownCallbackRegistry}} for cleanup. > Now this is moved to > {{org.apache.logging.log4j.core.appender.mom.jeromq.JeroMqManager}}, but > still there's this explicit code: > {code:xml} > if (enableShutdownHook) { > SHUTDOWN_HOOK = ((ShutdownCallbackRegistry) > LogManager.getFactory()).addShutdownCallback(CONTEXT::close); > {code} > While normally, LogManager.getFactor() returns an instance of > {{org.apache.logging.log4j.core.impl.Log4jContextFactory}}, it's *not* > guaranteed by {{org.apache.logging.log4j.LogManager#getFactory}} API and > indeed - pax-logging-api's implementation returns a factory that doesn't > implement {{ShutdownCallbackRegistry}}. > I tried two approaches: > # _move_ (in OSGi terms) some packages from log4j-core to pax-logging-api > (for now, pax-logging-api only operates on log4j-api), howver, transitively I > ended up with almost entire log4j-core inside pax-logging-api > # refactor log4j2 itself (locally) so {{ShutdownCallbackRegistry}} (and > {{Cancellable}}) are part of {{org.apache.logging.log4j.spi}} package, but I > ended with quite long list of errors from > org.revapi:revapi-maven-plugin:0.11.1:check > Mind that even > {{org.apache.logging.log4j.core.LoggerContext#setUpShutdownHook()}} correctly > checks for the interface to be implemented: > {code:java} > final LoggerContextFactory factory = LogManager.getFactory(); > if (factory instanceof ShutdownCallbackRegistry) { > {code} > It's *only* org.apache.logging.log4j.core.appender.mom.jeromq.JeroMqManager > that blindly calls: > {code:java} > SHUTDOWN_HOOK = ((ShutdownCallbackRegistry) > LogManager.getFactory()).addShutdownCallback(CONTEXT::close); > {code} > Summarizing - ideally (IMO) {{ShutdownCallbackRegistry}} should be part of > the API, but if it's not possible, please fix {{JeroMqManager}} to check for > the implementation. -- This message was sent by Atlassian Jira (v8.20.1#820001)