Confusing JRE and JDK package naming in Linux Distros

Observations on Installing Java Development Kit on Linux Distros

After recently switching to Linux, I encountered a notable difference in package naming conventions when installing Java Runtime Environment (JRE) and Java Development Kit (JDK). Many popular Linux distributions follow a similar pattern in naming these packages, but it can be a bit confusing at first.

Most distributions, including Fedora and Debian-based systems, provide:

• JRE package under the name java-xx-openjdk.arch
• JDK package as java-xx-openjdk-devel.arch

Quick Note on Installing Java JDK vs. JRE

It's easy to accidentally install only the JRE when you're actually looking to set up a full development environment (JDK), as the commands can appear deceptively similar.

For example:

# Installs only the Java Runtime Environment (JRE)
sudo apt install java-21-openjdk     # On Debian/Ubuntu
sudo dnf install java-21-openjdk     # On Fedora

# Installs the full Java Development Kit (JDK)
sudo apt install java-21-openjdk-devel
sudo dnf install java-21-openjdk-devel

Summary

If you simply run apt install java-21-openjdk or dnf install java-21-openjdk, it will only set up the JRE. To ensure you have the full JDK (JVM + JRE), use apt install java-21-openjdk-devel or dnf install java-21-openjdk-devel.

Below is a screenshot showing the Fedora package name and description for Java 21:

This should help anyone new to Linux avoid the same confusion when setting up Java.