.travis-toolchains.xml

<?xml version="1.0" encoding="UTF8"?>
<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 http://maven.apache.org/xsd/toolchains-1.1.0.xsd">
  <toolchain>
    <type>jdk</type>
    <provides>
      <id>java7</id>
      <version>1.7</version>
      <vendor>oracle</vendor>
    </provides>
    <configuration>
      <jdkHome>/usr/lib/jvm/java-7-oracle</jdkHome>
    </configuration>
  </toolchain>
  <toolchain>
    <type>jdk</type>
    <provides>
      <id>java8</id>
      <version>1.8</version>
      <vendor>oracle</vendor>
    </provides>
    <configuration>
      <jdkHome>/usr/lib/jvm/java-8-oracle</jdkHome>
    </configuration>
  </toolchain>
  <toolchain>
    <type>jdk</type>
    <provides>
      <id>java9</id>
      <version>9</version>
      <vendor>oracle</vendor>
    </provides>
    <configuration>
      <jdkHome>/usr/lib/jvm/java-9-oracle</jdkHome>
    </configuration>
  </toolchain>
</toolchains>