Install Oracle Java 9 https://askubuntu.com/questions/56104/how-can-i-install-sun-oracles-proprietary-java-jdk-6-7-8-or-jre https://tecadmin.net/install-oracle-java-8-ubuntu-via-ppa/ https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-get-on-ubuntu-16-04 https://fribeiro.org/tech/2018/02/07/nextcloud-full-text-elasticsearch/ http://www.oracle.com/technetwork/java/javase/downloads/index.html Download the 64-bit (or 32-bit) Linux “compressed binary file” into your…