JDK7, add these in your /etc/apt/sources.list file,

deb http://archive.ubuntu.com/ubuntu/ trusty main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
by issuing a following command,

sudo edit /etc/apt/sources.list
then run,

sudo apt-get update
run apt-cache search openjdk-7-jre to verify.