Install oracle/sun java on ubuntu 12.10

1. Open a terminal window.
2. Type in the following commands then hit Enter after each. 

• sudo sh -c "echo 'deb http://www.duinsoft.nl/pkg debs all' >> /etc/apt/sources.list"
• sudo apt-get update
• sudo apt-key adv --keyserver keys.gnupg.net --recv-keys 5CB26B26
• sudo apt-get update
• sudo apt-get install update-sun-jre

To install JDK 7 on i386 32-bit systems:

1. Open a terminal window.
2. Type in the following commands then hit Enter after each.
cd /tmp
wget -c --no-cookies --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com" "http://goo.gl/g9cJl" -O jdk-7u7-nb-7_2-linux-i586-ml.sh

• chmod +x jdk-7u7-nb-7_2-linux-i586-ml.sh
• sudo sh jdk-7u7-nb-7_2-linux-i586-ml.sh

To install JDK 7 on AMD 64-bit systems:

cd /tmp

wget -c --no-cookies --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com" "http://goo.gl/AJ1oS" -O jdk-7u7-nb-7_2-linux-x64-ml.sh

• chmod +x jdk-7u7-nb-7_2-linux-x64-ml.sh
• sudo sh jdk-7u7-nb-7_2-linux-x64-ml.sh

When the install is complete, use these commands:

• sudo mkdir -p /usr/lib/jvm/
• sudo cp -R /usr/local/jdk1.7.0* /usr/lib/jvm/
• sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0_07/bin/javac 1
• sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_07/bin/java 1

For more, see the original article at the link below.
http://www.itworld.com/software/305913/install-oracle-java-7-ubuntu-1210
and
http://www.upubuntu.com/2012/10/how-to-install-oracle-java-7-jre-7-jdk.html?m=0