Installing Java SE Development Kit on Ubuntu

- Download Java SE 7u7 from Oracle and uncompress it;

$ tar xf jdk-7u7-linux-i586.tar.gz

- JDK 7 package is extracted into jdk1.7.0_07 directory. Move this directory to "/usr/lib/jvm/";

$ sudo mv ./jdk1.7.0_07 /usr/lib/jvm/jdk1.7.0_07-sun

- Then, run;

$ sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0_07-sun/bin/java" 1

$ sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.7.0_07-sun/bin/javac" 1

$ sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.7.0_07-sun/bin/javaws" 1

- Set newly installed java as default;

$ sudo update-alternatives --config java

$ sudo update-alternatives --config javac

$ sudo update-alternatives --config javaws

- Check the version of new JDK 7 installation;

$ java -version

References;

(1)http://askubuntu.com/questions/55848/how-do-i-install-oracle-java-jdk-7

(2)http://greenmang0.wordpress.com/2012/05/28/installing-oracle-jdk-7-on-ubuntu-12-04