Install Java7, Java8 and Javaplugin for firefox in Ubuntu

The methods mentioned here have been tested. (11/19/2014)




Install Oracle Java7 in Ubuntu

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer

see : http://www.webupd8.org/2012/01/install-oracle-java-jdk-7-in-ubuntu-via.html








Install Java8 in Ubuntu

1. download jdk file
2. decompress the file tar xvzf jdk1.8*.tar.gz
3. relocate JDK 8: mv jkd1.8* / usr/lib/jvm
4. Install Oracle Java JDK 8
    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/java 1065
    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/javac 1065
    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/jar 1065
    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/javaws 1065
5. check or set the system java version in Use with: 
    sudo update-alternatives --config java

see : http://tutorialforlinux.com/2014/03/15/how-to-install-oracle-jdk-8-on-ubuntu-12-04-precise-lts-32-64bit-easy-guide/





Install Java plugin in Firefox

;;; install the Icedtea plugin
sudo apt-get install icedtea-plugin

;;; create a symbolic link
ln -s /usr/lib/jvm/jre1.7.0/lib/amd64/libnpjp2.so ~/.mozilla/plugins/

alternatively, one may find the plugins directory  in /usr/lib/mozilla

see : http://askubuntu.com/questions/354361/how-to-install-java-plugin-in-firefox