By default, the Maven Javadoc Plugin tries to auto-detect the Javadoc Tool executable from the Java property java.home or from the environment variable JAVA_HOME.

You could also specify the executable of the Javadoc Tool to use with the <javadocExecutable/> parameter. For example:

```<project>
...
<reporting> (or <build>)
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>2.9.1</version>
<configuration>
...
</configuration>
</plugin>
...
</plugins>
</reporting> (or </build>)
...
</project>```

IMPORTANT NOTE: by using <javadocExecutable/> parameter, the build will be plateform dependent! A good practice is to define an environnement variable (i.e. JAVA_1.6_HOME), so you could specify it: (i.e. <javadocExecutable>\${env.JAVA_1.6_HOME}/bin/javadoc</javadocExecutable>). An other ways is to define a POM property using <project><properties/></project>.

In the same way, the Maven Javadoc Plugin tries to auto-detect the Javadoc Tool version by calling javadoc -J-fullversion.

You could also specify the version of the Javadoc Tool executable. For example:

```<project>
...
<reporting> (or <build>)
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>