Install JRE on Ubuntu

Java Runtime Enviroment also known as JRE is part of Java Development Kit JDK a software development environment for writing Java applications. JRE consist Java Virtual Machine, core classes, and supporting files.
Installing JRE on ubuntu is a little bit different with installation JDK. First, Download the JRE file in here. Remember to download JRE version based on your system version either it's 32bit or 64bit.
After finished downloading your JRE version, we can begin the installation process.

1. Create new folder in opt directory. In terminal type this command "sudo mkdir -p -v /opt/java/64".
2. Go to folder containing your JRE download file(example: use"cd Downloads" to move to Download directory from your home directory) and unpack the file by typing "tar xvzf YOUR JRE FILE".
3. Moved unpacked contents into system folder that you created in step1. Type "sudo mv -v YOUR JRE FILE /opt/java/64".
4. Inform the system and make the new JRE become your system default.
   - sudo update-alternatives --install "/usr/bin/java" "java" "/opt/java/64/YOUR EXTRACTED JRE FILE/bin/java" 1
   - sudo update-alternatives --set java /opt/java/64/YOUR EXTRACTED JRE FILE/bin/java
5. Install Firefox plugins. Type "mkdir -v ~/.mozilla/plugins".
6. Removed IcedTea plugin, if it has been installed. type "sudo apt-get remove icedtea-6-plugin && sudo apt-get remove icedtea-7-plugin".
7. Remove an older version of the Java plugin. Type "rm -v ~/.mozilla/plugins/libnpjp2.so".
8. Install the plugin by creating symbolic link. Type "ln -s /opt/java/64/jre1.7.0_60/lib/amd64/libnpjp2.so ~/.mozilla/plugins/".
9. Close and restart Firefox
10. Type "about:plugins" in Firefox URL bar. If your installation is correct you will see something like this: