How to Install Oracle JDK 7 on Ubuntu 18.10 Cosmic Gnu/Linux

Oracle JDK 7 Ubuntu 18.10 - Setting Up

4. Next Relocate Oracle JDK 7 Contents
   Login as the SuperUser:

   sudo su

   If Got “User is Not in Sudoers file” then see: How to Enable sudo
   To Make a jvm Directory Only if Not already there
   (You can directly copy & paste the commands into the terminal)

   if [ ! -d "/usr/lib/jvm" ]; then mkdir /usr/lib/jvm; fi

   Set the root superUser as owner

   sudo chown -R root:root /tmp/jdk1.7*

   Then to shift the Oracle JDK 7 contents

   mv /tmp/jdk1.7* /usr/lib/jvm/
   

5. Installing Oracle Java JDK 7

   update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7*/bin/java 1065
   

   update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7*/bin/javac 1065
   

   update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.7*/bin/jar 1065
   

   update-alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.7*/bin/javaws 1065
   

   Checking or Setting the System Java Version in Use
   with

   update-alternatives --config java

   And for the Java Compiler instead:

   sudo update-alternatives --config javac

   To Switch of Java Version Just Enter the Selection Number on First, Column. :)
   Last Achieve the SuperUser session:

   exit

6. Setting JAVA_HOME User Environment Variable (Optional).

   Edit the Bash environment Configuration file:

   nano $HOME/.bashrc

   Append:

   export JAVA_HOME=/usr/lib/jvm/jdk1.7[uX]

   Replace the [uX] Looking for the Installed Java 7 Version with:

   ls /usr/lib/jvm/

   Ctr+x to Save & Exit from nano Editor :)
   Next to Load the New Bash Environment:

   bash