[ 
https://issues.apache.org/jira/browse/LOG4J2-587?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Adam Gent updated LOG4J2-587:
-----------------------------

    Description: 
The log4j 1.2 emulation jar does not contain {{AppenderSkeleton}}. There are 
several Spring components like spring-amqp that define custom appenders. 

Even if you don't reference those appenders because of various class loading 
discovery (such as Springs annotation configuration) you will get exceptions 
like

{code}
java.lang.NoClassDefFoundError: org/apache/log4j/AppenderSkeleton
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2531)
        at java.lang.Class.getDeclaredMethods(Class.java:1855)
        at 
org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findPersistenceMetadata(
{code}

And thus you cannot remove the original log4j-1.2.x jars.

Basically the class just needs to exist to avoid reflection exceptions like the 
one above. Unfortunately this is a show stopper for us as we use Spring heavily 
and and it appears to happen on any of our spring applications and we don't 
allow jars with duplicate classes in our projets.

This appears to be an easy fix... just stub all of the log4j-1.2 classes that 
are extendable.

The log4j SLF4J bridge does in fact contain the appender skeleton: 
http://www.slf4j.org/api/org/apache/log4j/package-summary.html

Consequently a not so ideal workaround is to just use {{log4j-over-slf4j.jar}} 
which does contain the AppenderSkeleton.

  was:
The log4j 1.2 emulation jar does not contain {{AppenderSkeleton}}. There are 
several Spring components like spring-amqp that define custom appenders. 

Even if you don't reference those appenders because of various class loading 
discovery (such as Springs annotation configuration) you will get exceptions 
like

{code}
java.lang.NoClassDefFoundError: org/apache/log4j/AppenderSkeleton
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2531)
        at java.lang.Class.getDeclaredMethods(Class.java:1855)
        at 
org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findPersistenceMetadata(
{code}

And thus you cannot remove the original log4j-1.2.x jars.

Basically the class just needs to exist to avoid reflection exceptions like the 
one above. Unfortunately this is a show stopper for us as we use Spring heavily 
and and it appears to happen on any of our spring applications and we don't 
allow jars with duplicate classes in our projets.

This appears to be an easy fix... just stub all of the log4j-1.2 classes that 
are extendable.


> log4j-1.2-api emulation jar missing classes
> -------------------------------------------
>
>                 Key: LOG4J2-587
>                 URL: https://issues.apache.org/jira/browse/LOG4J2-587
>             Project: Log4j 2
>          Issue Type: Bug
>          Components: log4j 1.2 emulation
>    Affects Versions: 2.0-rc1
>            Reporter: Adam Gent
>              Labels: easyfix
>
> The log4j 1.2 emulation jar does not contain {{AppenderSkeleton}}. There are 
> several Spring components like spring-amqp that define custom appenders. 
> Even if you don't reference those appenders because of various class loading 
> discovery (such as Springs annotation configuration) you will get exceptions 
> like
> {code}
> java.lang.NoClassDefFoundError: org/apache/log4j/AppenderSkeleton
>       at java.lang.Class.getDeclaredMethods0(Native Method)
>       at java.lang.Class.privateGetDeclaredMethods(Class.java:2531)
>       at java.lang.Class.getDeclaredMethods(Class.java:1855)
>       at 
> org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findPersistenceMetadata(
> {code}
> And thus you cannot remove the original log4j-1.2.x jars.
> Basically the class just needs to exist to avoid reflection exceptions like 
> the one above. Unfortunately this is a show stopper for us as we use Spring 
> heavily and and it appears to happen on any of our spring applications and we 
> don't allow jars with duplicate classes in our projets.
> This appears to be an easy fix... just stub all of the log4j-1.2 classes that 
> are extendable.
> The log4j SLF4J bridge does in fact contain the appender skeleton: 
> http://www.slf4j.org/api/org/apache/log4j/package-summary.html
> Consequently a not so ideal workaround is to just use 
> {{log4j-over-slf4j.jar}} which does contain the AppenderSkeleton.



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