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https://issues.apache.org/jira/browse/LOG4J2-400?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13882482#comment-13882482
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Matt Sicker commented on LOG4J2-400:
------------------------------------

Linking this to an epic for OSGi support.

> Provide Appender-Bundles
> ------------------------
>
>                 Key: LOG4J2-400
>                 URL: https://issues.apache.org/jira/browse/LOG4J2-400
>             Project: Log4j 2
>          Issue Type: Improvement
>          Components: Appenders, Core
>    Affects Versions: 2.0-beta9
>         Environment: OSGi R4 / R5 (Apache Felix 4.x)
>            Reporter: Roland Weiglhofer
>            Priority: Critical
>              Labels: Appender, Core, Dependency, OSGi, PluginManager, 
> lightweight, optional
>
> Instead of deploying all appenders in the core fragment, it would be much 
> better if the customer can choose which appender he wants to provide. It's 
> easy to hive the appender off in a separate bundle fragment. The host bundle 
> is the API bundle. The Plugin Manager (core fragment) finds the deployed 
> appenders in the classpath of the host bundle. The PluginManager should parse 
> the class path in a separate thread (Startup-Hook) and only once at the start 
> of the host bundle, but not for each call (when a consumer bundle aquires a 
> logger). Make package-imports optional 
> (<Import-Package>*;resolution:=optional</Import-Package>)!!!!
> This reduces the number of dependencies and reduces the startup time of the 
> whole system.
> One possible solution for the Plugin Manager is to use the reflections plugin 
> during the maven build process. This plugin lists all classes of a project 
> within a xml file. This file can be marked as a bundle resource and is stored 
> within the appender bundle fragment. The idea is that each appender fragment 
> has its own class list. Because the bundle host (log4j2 core) sees all 
> resources of its fragments it can load these class lists at runtime. Thus, 
> the Plugin Manager gets only those appenders that are installed  within 
> deployed bundle fragements. The class list is created during the build 
> process, the plugin manager must not parse the classpath at runtime. Log4j2 
> uses a xml parser by default. An additional new dependency to a xml-parser 
> library is not required.
>         <plugin>
>         <groupId>org.reflections</groupId>
>         <artifactId>reflections-maven</artifactId>
>         <version>0.9.8</version>
>           <executions>
>             <execution>
>               <goals>
>                 <goal>reflections</goal>
>               </goals>
>             <phase>process-classes</phase>
>           </execution>
>         </executions>
>         <configuration>
>           
> <destinations>${project.basedir}/META-INF/reflections/${project.artifactId}-reflections.xml</destinations>
>         </configuration>
>       </plugin>



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