How to Install Oracle JDK 1.8 in Ubuntu 18.04 LTS?

1. Download JDK 1.8.172

2. Unzip

# sudo mv ~/Download/jdk-8u172-linux-x64.tar.gz /opt
# cd /opt
# sudo tar zxvf jdk-8u172-linux-x64.tar.gz
# sudo chown -R root:root jdk1.8.0_172/
# sudo ln -s jdk1.8.0_172/ jdk

3. Set Env

# sudo vim /etc/profile.d/java-sdk-env.sh

export JAVA_HOME=/opt/jdk
export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$PATH:$JAVA_HOME/bin

:wq!

4. Reboot

# sudo reboot

5. Check

# java -version

java version "1.8.0_172"
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)