Tech Ubuntu 14.04 update : Install Java JDK in Ubuntu 14.04 : the manual way

 how Install Java JDK in Ubuntu 14.04 : the manual way

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There is a similar answer on how to install JRE 8. Install Java JDK The manual way Download the 32bit or 64bit Linux "compressed binary file" - it has a ".tar.gz" file extension. Uncompress it tar -xvf jdk-8-linux-i586.tar.gz (32bit) tar -xvf jdk-8-linux-x64.tar.gz (64bit) JDK 8 package is extracted into ./jdk1.8.0 directory. N.B. check carefully this folder name since Oracle seem to change this occasionally with each update. Now move the JDK 8 directory to /usr/lib sudo mkdir -p /usr/lib/jvm sudo mv ./jdk1.8.0 /usr/lib/jvm/ Now run sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.8.0/bin/java" 1 sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.8.0/bin/javac" 1 sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.8.0/bin/javaws" 1 This will assign Oracle JDK a priority of 1, which means that installing other JDKs will replace it as the default. Be sure to use a higher priority if you want Oracle JDK to remain the default. Correct the file ownership and the permissions of the executables: sudo chmod a+x /usr/bin/java sudo chmod a+x /usr/bin/javac sudo chmod a+x /usr/bin/javaws sudo chown -R root:root /usr/lib/jvm/jdk1.8.0 N.B. remember - Java JDK has many more executables that you can similarly install as above. java, javac, javaws are probably the most frequently required. This answer lists the other executables available. Run sudo update-alternatives --config java You will see output similar one below - choose the number of jdk1.8.0 - for example 3 in this list (unless you have have never installed Java installed in your computer in which case a sentence saying "There is nothing to configure" will appear): $ sudo update-alternatives --config java There are 3 choices for the alternative java (providing /usr/bin/java).

to enable Mozilla Firefox plugin:

32 bit:  ln -s /usr/lib/jvm/jdk1.8.0/jre/lib/i386/libnpjp2.so ~/.mozilla/plugins/    64 bit:  ln -s /usr/lib/jvm/jdk1.8.0/jre/lib/amd64/libnpjp2.so ~/.mozilla/plugins/

N.B. you can link the plugin (libnpjp2.so) to /usr/lib/firefox/plugins/ for a system wide installation, For Ubuntu 13.10 path to plugin directory is /usr/lib/firefox/browser/plugins/

Depending on your configuration, you might need to update the apparmor profile for firefox (or other browsers) in /etc/apparmor.d/abstractions/ubuntu-browsers.d/java

read more and completely at http://askubuntu.com/questions/56104/how-can-i-install-sun-oracles-proprietary-java-jdk-6-7-8-or-jre/55960#55960