settings.xml.example

<!--
 | settings.xml is a configuration file for Maven. It can be specified at two
 | levels:
 |
 |  1. User Level. This settings.xml file provides configuration for a single
 |                 user, and is normally provided in
 |                 ${user.home}/.m2/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -s /path/to/user/settings.xml
 |
 |  2. Global Level. This settings.xml file provides configuration for all
 |                 Maven users on a machine (assuming they're all using the
 |                 same Maven installation). It's normally provided in
 |                 ${maven.home}/conf/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -gs /path/to/global/settings.xml
 |
 | The example below demonstrates how to add custom properties which will be
 | accessible during the Maven build process. Specifically the JDK source
 | files and Guava source files are used by the maven-javadoc-plugin.
 |-->
 
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 https://maven.apache.org/xsd/settings-1.0.0.xsd">

    <profiles>
        <profile>
            <id>properties</id>
            <properties>
                <java.sourceDirectory>${env.JAVA_HOME}/src</java.sourceDirectory>
                <guava.sourceDirectory>...</guava.sourceDirectory>                
            </properties>
        </profile>
    </profiles>

    <activeProfiles>
        <activeProfile>properties</activeProfile>
    </activeProfiles>
</settings>