Install Java on Ubuntu

Declare Oracle Java 8 Repository :

sudo add-apt-repository ppa:webupd8team/java

Then, refresh local repository index :

sudo apt-get update

And install with :

sudo apt-get install oracle-java8-installer

Source : https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-get-on-ubuntu-16-04