How to Install Oracle JDK 8 on Debian Stretch 9 Easy Guide

Installing

2. 2. Downloading

   Download Oracle Java SE JDK8 for Linux.

   Oracle JDK8 i586/x8664 tar.gz

   Oracle Jdk8

3. 3. Extracting

   Then Extract into /tmp
   Possibly Double-Click/Right-Click and Open with Archive Manager:

   
   Or from Shell:

   tar xvfz ~/Downloads/jdk-8*.tar.gz -C /tmp/

4. 4. Installing

   Then to Install Oracle JDK 8
   First, Make a jvm Directory if Not already there with:

   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*

   Again reiterate the Execution Permission also over the Java binaries:

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

   Finally, to Shift the Java contents:

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

5. 5. Updating

   Finally, Update System Java to Oracle JDK 8
   Run All these Commands below:

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

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

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

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

   Then to Check or Set the System Java Version in Use do:

   sudo update-alternatives --config java

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

6. 6. Setting Up JAVA_HOME

   Finally, to Set Up JAVA_HOME User Environment Variable (Optional)
   And Edit the User’s 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/ | grep jdk1.8

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

   bash