To use the plugin, you've got two options: First of all, it can create a simple text file, called target/rat.txt, with the plugin's output. This is done by invoking the apache-rat:check goal.
You may also add a report to the generated site. This is your second option.
To create a text file with the report, you need to run the apache-rat:check goal. Add a section like the following to your POM:
<build>
<plugins>
...
<plugin>
<groupId>org.apache.rat</groupId>
<artifactId>apache-rat-plugin</artifactId>
<version>0.16.1</version>
</plugin>
...
</plugins>
</build>Once you have done that, the plugin can be run from the command line by simply typing
mvn apache-rat:check
An example for running the plugin automatically can be found here.
A section like the following must be added to your POM:
<reporting>
<plugins>
...
<plugin>
<groupId>org.apache.rat</groupId>
<artifactId>apache-rat-plugin</artifactId>
<version>0.16.1</version>
</plugin>
...
</plugins>
</reporting>The report will be created automatically when you generate the site:
mvn site