Installation on Linux

There are several ways to install Java on Linux, depending on its flavor. Here, I will describe an installation method that works more or less the same way on all flavors. The one I used is Debian.

First step is the same as in any other operating system: download the installation kit. In the case of Linux, you should select a package that has a tar.gz ending. This is a compressed archive format. You should also carefully select the package that matches the processor in your machine and the 32/64 bit version of the operating system. After the package is downloaded, you have to switch to root mode, issuing the su command. This the first command you can see on the screenshot that shows the installation commands.

The tar command uncompressed the archive into a subfolder. In Debian, this subfolder has to be moved to /opt/jdk and the mv command is used for this purpose. The two update-alternatives command is Debian-specific. These tell the operating system to use this newly installed Java in case there is already an older Java installed. The Debian I was using to test and demonstrate the installation process on a virtual machine came with a 7 year old version of Java.

The final step of the installation is the same as any other operating system: checking that the installation was successful in issuing the java -version command. In the case of Linux, this is even more important because the installation process does not check that the downloaded version matches the operating system and the processor architecture.