How to Install JDK 8 (Java 8) In Linux

01) Download Orale JDK 8
//Link
https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html

02) Open Your Terminal(Ctrl + alt + T)

03) cd Downloads

04) sudo mkdir /usr/lib/jvm

05) cd /usr/lib/jvm

06) sudo tar -xvzf ~/Downloads/jdk-8u271-linux-x64.tar.gz

07) sudo gedit /etc/environment
(if your computer haven't gedit.. install using this command (sudo apt-get install gedit) )

08) After opened file,add followings command in your variable file

/usr/lib/jvm/jdk1.8.0_271/bin
/usr/lib/jvm/jdk1.8.0_271/db/bin
/usr/lib/jvm/jdk1.8.0_271/jre/bin

J2SDKDIR="/usr/lib/jvm/jdk1.8.0_271"
J2REDIR="/usr/lib/jvm/jdk1.8.0_271/jre"
JAVA_HOME="/usr/lib/jvm/jdk1.8.0_271"
DERBY_HOME="/usr/lib/jvm/jdk1.8.0_271/db"

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/jdk1.8.0_271/bin:/usr/lib/jvm/jdk1.8.0_271/db/bin:/usr/lib/jvm/jdk1.8.0_271/jre/bin"
J2SDKDIR="/usr/lib/jvm/jdk1.8.0_271"
J2REDIR="/usr/lib/jvm/jdk1.8.0_271/jre"
JAVA_HOME="/usr/lib/jvm/jdk1.8.0_271"
DERBY_HOME="/usr/lib/jvm/jdk1.8.0_271/db"

09) Save and close the file.

09) Enter Following commands in your Terminal

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.8.0_271/bin/java" 0

sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.8.0_271/bin/javac" 0

sudo update-alternatives --set java /usr/lib/jvm/jdk1.8.0_271/bin/java

sudo update-alternatives --set javac /usr/lib/jvm/jdk1.8.0_271/bin/javac

10) Verify the setup

update-alternatives --list java

update-alternatives --list javac

11)Check the Java Version

java -version