Delete Additional Files Not Exposed to Maven

The maven-clean-plugin will delete the target directory by default. You may configure it to delete additional directories and files. The following example shows how:

<build>
  [...]
  <plugin>
    <artifactId>maven-clean-plugin</artifactId>
    <configuration>
      <filesets>
        <fileset>
          <directory>some/relative/path</directory>
          <includes>
            <include>**/*.tmp</include>
            <include>**/*.log</include>
          </includes>
          <excludes>
            <exclude>**/important.log</exclude>
            <exclude>**/another-important.log</exclude>
          </excludes>
          <followSymlinks>false</followSymlinks>
        </fileset>
      </filesets>
    </configuration>
  </plugin>
  [...]
</build>

Note: The directory in the fileset is a relative path inside a project, in other words,

  <directory>some/relative/path</directory>

is equivalent to:

  <directory>${basedir}/some/relative/path</directory>

You could also define file set rules in a parent POM. In this case, the clean plugin adds the subproject basedir to the defined relative path.