how-to-install-oracle-java-7-update-45-on-ubuntu-12-10-linux

wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F" http://download.oracle.com/otn-pub/java/jdk/7u45-b18/jdk-7u45-linux-x64.tar.gz
tar -xvzf jdk-7u45-linux-x64.tar.gz  -C /usr/lib/jvm
cd /usr/lib/jvm
ls -ltr
update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.7.0_45/bin/javac" 1
update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0_45/bin/java" 1
update-alternatives --set "javac" "/usr/lib/jvm/jdk1.7.0_45/bin/javac"
update-alternatives --set "java" "/usr/lib/jvm/jdk1.7.0_45/bin/java"
java -version
javac -version


Source :

http://hendrelouw73.wordpress.com/2013/10/16/how-to-install-oracle-java-7-update-45-on-ubuntu-12-10-linux/