PMD

Links

maven-pmd-plugin

Sample

<reporting>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-pmd-plugin</artifactId>
      <configuration>
        <targetJdk>1.5</targetJdk>
        <xrefLocation>${project.reporting.outputDirectory}/../xref</xrefLocation>
      </configuration>
    </plugin>
</reporting>