Java

Installation

Install Oracle JDK 9 (considered stable in 3/2018)

su -
add-apt-repository ppa:webupd8team/java
apt-get update
apt-get install oracle-java9-installer
emacs /etc/environment
 JAVA_HOME="/usr/lib/jvm/java-9-oracle"

There was reorganization of some xml parsers from/to EE, from what I was told, so you might need to stick with Java 8:

apt-get install oracle-java8-installer