How to Install Oracle JDK 8 Ubuntu 18.04 Bionic

4. Setting Up Oracle JDK

Then to Setup Oracle JDK 8.

First, make a jvm Directory if Not already there with:

sudo su -c 'if [ ! -d "/usr/lib/jvm" ]; then mkdir /usr/lib/jvm; fi'

Set the root superUser as owner:

sudo chown -R root:root /tmp/jdk1.8*

Reiterate the Execution Permission over the Java binaries:

sud chmod -R +x /tmp/jdk1.8*/bin

Finally, Shift the Java contents with:

sudo mv /tmp/jdk1.8* /usr/lib/jvm/

If Got “User is Not in Sudoers file” then see: How to Enable sudo

5. Installing Oracle JDK

Then to Install Oracle Java JDK 8
You can directly Copy & Paste the Commands into Terminal…
Execute this Sequence of Commands:

update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/java 1065

update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8*/bin/javac 1065

update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8*/bin/jar 1065

update-alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.8*/bin/javaws 1065

Checking or Setting the System Java Version in Use with

update-alternatives --config java

Finally, to Switch of Java Version Just Enter the Selection Number on First, Column. :)

6. Setting Up Environment

(Optional) Setting JAVA_HOME User Environment Variable
Edit the Bash environment Configuration file:

nano $HOME/.bashrc

And Append:

export JAVA_HOME=/usr/lib/jvm/jdk1.8[uX]

Replace the [uX] Looking for the Installed Java 8 Version with:

ls /usr/lib/jvm/

Ctr+x to Save & Exit from nano Editor :)
Load New Bash Config:

bash

7. Testing Oracle JDK

Finally, Test Java JDK 8 Installation
By:

java -version