How to Install the Java Runtime Environment on Ubuntu 22.04
Java Runtime Environment (JRE) is required to run Java programs. The two most popular on Ubuntu are OpenJDK and Oracle HotSpot. In this video, we’ll be going through the installation of both JRE packages.Most you only need to choose the one that best suits your needs.
Some Commands
sudo update-alternatives --config java
sudo update-alternatives --config javac
sudo update-alternatives --config jar
export J2SDKDIR=/usr/lib/jvm/jdk-18
export J2REDIR=/usr/lib/jvm/jdk-18
export PATH=$PATH:/usr/lib/jvm/jdk-18/bin:/usr/lib/jvm/jdk-18/db/bin
export JAVA_HOME=/usr/lib/jvm/jdk-18
export DERBY_HOME=/usr/lib/jvm/jdk-18/db
setenv J2SDKDIR /usr/lib/jvm/jdk-18
setenv J2REDIR /usr/lib/jvm/jdk-18
setenv PATH ${PATH}:/usr/lib/jvm/jdk-18/bin:/usr/lib/jvm/jdk-18/db/bin
setenv JAVA_HOME /usr/lib/jvm/jdk-18
setenv DERBY_HOME /usr/lib/jvm/jdk-18/db