Open JDK Installation
---------------------

# sudo apt install openjdk-8-jdk

oder 

# sudo apt install openjdk-11-jdk


---------------------------------------------------------------------------------------------

Oracle JDK Installation per APT
-------------------------------

Java 8

  # sudo add-apt-repository ppa:webupd8team/java
  # sudo apt update
  # sudo apt install oracle-java8-set-default
  # sudo ln -s /usr/lib/jvm/java-8-oracle /usr/lib/jvm/java-8 


Java 10

  # sudo add-apt-repository ppa:linuxuprising/java
  # sudo apt update
  # sudo apt install oracle-java10-set-default
  # sudo ln -s /usr/lib/jvm/java-10-oracle /usr/lib/jvm/java-10


In beiden Fällen mus die Umgebungsvariable trotz Installation per 
APT manuell gesetzt werden!

> /etc/profile

#*** JAVA ENVIRONMENT definieren ***
export JAVA_HOME=/usr/lib/jvm/java-8