Hello Linux Geeksters. As you may know, Oracle Java 9 is scheduled for release in 2016, but an early release has been made available.
The Oracle theme is trying to optimize the JIT compiler and starting with Java 9, the java software will be modular and will replace the .jar files, which will still be supported.
For now, it is recommended to stick to Java 8, which is stable. Use Java 9 only if you explicitly need it.
In this article article I will show you how to install Java 9 on Ubuntu 15.04 Vivid Vervet, Ubuntu 14.10 Utopic Unicorn, Ubuntu 14.04 Trusty Tahr, Ubuntu 12.04 Precise Pangolin, Linux Mint 17.1 Rebecca, Linux Mint 17 Qiana, Linux Mint 13 Maya, Pinguy OS 14.04, Elementary OS 0.3 Freya, Elementary OS 0.2 Luna, Deepin 2014, Peppermint Five, LXLE 14.04, Linux Lite 2, Debian Jessie, Debian Wheezy and other Ubuntu and Debian derivative systems.
For Ubuntu 15.04, Ubuntu 14.10 Utopic Unicorn, Ubuntu 14.04 Trusty Tahr, Ubuntu 12.04 Precise Pangolin, and derivative systems, we have to add the ppa to our system, update the local repository index and install the oracle-java9-installer package:
$ sudo add-apt-repository ppa:webupd8team/java
$ sudo apt-get update
$ sudo apt-get install oracle-java9-installer
In order to install Java 9 on Debian systems, we have to add the repository for trusty to your system and the key, update the local repository index and install the oracle-java9-installer package:
$ sudo sh -c 'echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" >> /etc/apt/sources.list'
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
$ sudo apt-get update
$ sudo apt-get install oracle-java9-installer