Adding file to jar during maven build

Question

I am trying to add a license file to all of my jars when executing a maven build. I have the license on each class file, but I am looking to add License.txt to each META-INF folder within each jar

My project has a master pom, which has half dozen modules, those modules then have modules of their own, and eventually get to a project that generates a /target/<.jar-file>. The build and the class level licenses are working, I am just looking to add a physical License.txt into the META-INF folder.

My file is stored (relative to the master POM) in /src/resources/src-license.txt. I really need the automated method to ensure that if/when the license changes, I dotn have to update 50 files, I can just update the one, which is then copied out to the other locations.

I have tried using

<build>
  <sourceDirectory>src</sourceDirectory>
  <resources>
    <resource>
      <directory>src/resources</directory>
      <targetPath>/META-INF</targetPath>
      <includes>
        <include>src-license.txt</include>
      </includes>
    </resource>
  </resources>
....
</build>

But that doesnt seem to do the trick. I have also tries some alternatives to the output path, such as ${project.build.outputDirectory}/META-INF, or */META_INF, also to no avail. Does anyone have some experience on how to accomplish this? Thanks

Also, I use the maven-license-plugin to ensure that each class file has the license info pasted into it, and that functions as intended. But again, that inside the class files, I am looking for an external .txt file in each <*.jar>/META-INF/

Answer 1

Using resources from parent relativePath is at least difficult (what if you have a complex directory structure?).

A simple and clean way can be to create a separate module containing your src-license.txt file. Then make it a dependency of your modules and unzip it (dependency:unpack-dependencies) @ generate-resources phase, inside target/classes.

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <executions>
            <execution>
                <id>unpack-license</id>
                <phase>generate-resources</phase>
                <goals><goal>unpack</goal></goals>
                <configuration>
                    <artifactItems>
                        <artifactItem>
                            <groupId>com.acme</groupId>
                            <artifactId>com.acme.license</artifactId>
                            <version>${project.version}</version>
                        </artifactItem>
                    </artifactItems>
                    <outputDirectory>${project.build.outputDirectory}</outputDirectory>
                </configuration>
            </execution>
        </executions>
    </plugin>