Java

Install Oracle JDK (Desktop)

• Download Link
• Choose 'Linux x64 Compressed Archive', save file (say jdk-8u261-linux-x64.tar.gz)
• Extract the file , it has jre & other lib tools

Install Open JDK (Desktop/ Server)

• Install open jdk specific binaries

sudo apt install openjdk-8-jre

//better in laptop install openjdk-8-jdk

Set environment variables (server)

• add below lines in /etc/profile

export JAVA_HOME="/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre"

export PATH="$JAVA_HOME/bin:$PATH"

export TZ="$(sudo cat /etc/timezone)"

Note : TZ for oracle time zone error

Set environment variables (desktop)

• add below lines in ~/.profile (check that file syntax)

JAVA_HOME="/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre"

PATH="$JAVA_HOME/bin:$PATH"

TZ="Asia/Kolkata"

Note : TZ for oracle time zone error

Oracle issue

//restart after following commands

sudo localectl set-locale LANG=en_US.UTF-8

sudo localectl set-locale LC_NUMERIC=en_US.UTF-8

sudo localectl set-locale LC_MONETARY=en_US.UTF-8

sudo localectl set-locale LC_TIME=en_US.UTF-8

OR

sudo update-locale LANG=en_US.UTF-8

sudo update-locale LC_NUMERIC=en_US.UTF-8

sudo update-locale LC_MONETARY=en_US.UTF-8

sudo update-locale LC_TIME=en_US.UTF-8

Note : also check /etc/default/locale file

Verify

• Logout & restart terminal

• Verify variables

echo $JAVA_HOME

echo $PATH

• Verify Java version

java -version