# JAVA_HOME environment variable is important because many Java-based applications such as Apache Tomcat, Maven, Gradle use this variable to JDK installed path..
# get the path of java installation
which javac
# check if the file is a link or a file
ls -la /usr/bin/javac
ls -la /etc/alternatives/javac
ls -la /usr/lib/jvm/java-8-openjdk-amd64/bin/javac
# so our javac is actually installed in this path we need to set this as the Java home path
# lets get that path only with this command here -f means follow all links till reaching the final path
jdk_dir=$(dirname $(dirname $(readlink -f $(which javac))))
# verify the path you got is correct.
echo $jdk_dir
# check path and java home before setting them.
echo $PATH
echo $JAVA_HOME
# set java home variable
echo "export JAVA_HOME=$jdk_dir" >> ~/.bashrc
# add java home to path variable
echo "export PATH=\$PATH:\$JAVA_HOME/bin" >> ~/.bashrc
# Apply the changes
source ~/.bashrc
# Print the JAVA_HOME and PATH environment variable
echo $JAVA_HOME
echo $PATH
