I followed the instruction from http://www.webupd8.org/2014/03/how-to-install-oracle-java-8-in-debian.html and it works fine.
Although I had some “Additional Java arguments:” which dident work with the newly installed java version, so I had to clear those first.
But after that, it works fine,
su -
echo “deb Index of /webupd8team/java/ubuntu trusty main” | tee /etc/apt/sources.list.d/webupd8team-java.list
echo “deb-src Index of /webupd8team/java/ubuntu trusty main” | tee -a /etc/apt/sources.list.d/webupd8team-java.list
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
apt-get update
apt-get install oracle-java8-installer