.m2/toolchains.xml for java-8-oracle on Ubuntu 16.04. H2Database's pom.xml needs this setting.

toolchains.xml

<?xml version="1.0" encoding="UTF8"?>
<toolchains>
    <!-- JDK toolchains -->
    <toolchain>
        <type>jdk</type>
        <provides>
            <version>1.6</version>
            <vendor>sun</vendor>
        </provides>
        <configuration>
            <jdkHome>/usr/lib/jvm/java-8-oracle </jdkHome>
        </configuration>
    </toolchain>
</toolchains>