Maven Shade Plugin Extensions

This project contains a collection of resource transformers for the Apache Maven Shade Plugin that allows you to use additional Log4j 2.x Core component modules.

Log4j Plugin Cache Transformer

A resource transformer for the Apache Maven Shade Plugin that merges Log4j2Plugins.dat plugin caches from all the jars containing Log4j 2.x Core components.

This transformer was formerly available at edwgiz/maven-shaded-log4j-transformer and was donated to the Apache Software Foundation by its author.

Usage

This resource transformer is usually used together with the ManifestResourceTransformer and ServicesResourceTransformer to integrate Log4j 2.x libraries in a shaded JAR.

A typical configuration is:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-shade-plugin</artifactId>
  <version>3.4.1</version>
  <dependencies>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-transform-maven-shade-plugin-extensions</artifactId>
      <version>0.2.0</version>
    </dependency>
  </dependencies>
  <executions>
    <execution>
      <id>shade-jar-with-dependencies</id>
      <phase>package</phase>
      <goals>
        <goal>shade</goal>
      </goals>
      <configuration>
        <transformers>
          <transformer implementation="org.apache.logging.log4j.maven.plugins.shade.transformer.Log4j2PluginCacheFileTransformer"/>
          <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
          <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
            <manifestEntries>
              <Multi-Release>true</Multi-Release>
            </manifestEntries>
          </transformer>
        </transformers>
      </configuration>
    </execution>
  </executions>
</plugin>