$ Java -version  $ sudo dpkg -i jdk-version.deb  $ ls /user/lib/jvm   $ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-16.0.1/bin/java 1   $ sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-16.0.1/bin/javac 1  $ java -version   $ javac -version