In this tutorial, we will show you how to install Java on Debian 9 Stretch. Many programs and scripts require java to run, but usually, Java is not installed by default on VPS or Dedicated Server.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS.  The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of JRE (Java Runtime Environment) and JDK (Java Development Kit) on Debian 9 (Stretch).

Prerequisites

• A server running one of the following operating systems: Debian 9 (Stretch).
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Java on Debian 9 Stretch

Step 1. Before we install any software, it’s important to make sure your system is up to date by running the following apt-get commands in the terminal:

apt-get update
apt-get upgrade

Step 2. Installing Java on Debian 9 Stretch.

Method 1. Install Java using apt:

apt-get install default-jre

To install the Java Developer Kit (JDK), execute this command:

apt-get install default-jdk

Method 2: Manual installation of OpenJDK:

First, Go to the download page for the OpenJDK software package, and right-click on the tar.gz link found to the right of the “Linux” option. Click on “Copy link address” or “Copy link”.

wget <paste-the-download-link>

Create a directory where you wish to install your OpenJDK environment:

mkdir <enter-path-and-directory-name>

Then, extract the tarball to your new directory:

tar xvzf openjdk-10.0.1_linux-x64_bin.tar.gz -C <path-to-your-new-directory>

Next, Create a new file in /etc/profile.d/ named “jdk10.sh”. The full path should be “/etc/profile.d/jdk10.sh”:

export JAVA_HOME="<insert-install-directory>/jdk-10.0.1"
export PATH="$PATH:${JAVA_HOME}/bin"

Verify the installed Java version:

java -version

Congratulations! You have successfully installed Java. Thanks for using this tutorial for installing Oracle Java (JRE or JDK) on Debian 9 Stretch system. For additional help or useful information, we recommend you check the official Java website.