Apache Maven Javadoc Plugin – Generate Javadoc without duplicate execution of phase generate-sources.

Generate Javadoc without duplicate execution of phase generate-sources.

The standard goals javadoc and test-javadoc invoke separate lifecyles generate-sources and generate-test-sources.
In a CI environment you now might execute something like mvn clean deploy site site-deploy.
During site build the standard reports will trigger generate-sources or generate-test-sources again, depending on your build this may take some time, because stuff like enforcer or generating stubs from a WDSL will be invoked again, which may lead to longer build times.
See MJAVADOC-369 as well.
As of version 2.10 two new reports are defined, javadoc-no-fork and test-javadoc-no-fork which will not trigger above phases a second time.

Configure this in your reporting section as follows:

<project>
  ...
  <reporting>
    <excludeDefaults>true</excludeDefaults>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-javadoc-plugin</artifactId>
        <version>3.5.0</version>
        <reportSets>
          <reportSet>
            <reports>
              <report>javadoc-no-fork</report>
              <report>test-javadoc-no-fork</report>
            </reports>
          </reportSet>
        </reportSets>
      </plugin>
    </plugins>
  </reporting>
  ...
</project>

Note: These reports may not be used for aggregate reports. For those, see the example of generating aggregate Javadocs without execution of phase compile.