Java 8 is now available according to http://openjdk.java.net/projects/jdk8/, but http://openjdk.java.net/install/ does not yet mention how to install OpenJDK 8 (not Oracle Java) on Ubuntu 14.04 Long Term Support. (For 14.10 and later just run apt-get install openjdk-8-jdk
)
How and when can this be done?
(2017-08-08: The very short answer is: OpenJDK 8 as of 2017-08-08 is not officially available from the official repositories as an APT package for Ubuntu 14.04. See full summary in this answer)
Note: For now we will use Oracle Java – the optimal solution for me is, however, OpenJDK from the Ubuntu repositories, until Oracle Java is available directly and effortless from the Ubuntu repositories.
Best Answer
You can do this for;
Final Update
JDK
JRE
Old Update
I found two repository but I do not recommend
OpenJDK builds (all archs)
OpenJDK 8 backport for trusty
Original Message
If you really want to use OpenJDK, you have to compile from source. There is not still any PPA for OpenJDK.
It has been requested at https://bugs.launchpad.net/ubuntu/+bug/1297065
I recommend you to use Webup8 Oracle Java8 Installer
To automatically set up the Java 8 environment variables
Check it
So you have to wait to use OpenJDK8