Instalando Java 8 em Debian Like

• # echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | sudo tee /etc/apt/sources.list.d/webupd8team-java.list
• # echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | sudo tee -a /etc/apt/sources.list.d/webupd8team-java.list
• # apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
• # aptitude update
• # apt-get install oracle-java8-installer

Testado em Ubuntu-14.10 e Mint-17.1