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Java is a widely used programming language and runtime environment, essential for running many applications and development tools. On CentOS 9, installing Java is straightforward using the default package manager.
Step 1: Update System Packages
Before installing new software, it’s always a good practice to update your system repositories:
sudo dnf update -y
Step 2: Install OpenJDK
CentOS 9 includes OpenJDK in its repositories. The recommended long-term support version is OpenJDK 17. Install it along with development tools:
sudo dnf install java-17-openjdk java-17-openjdk-devel -y
Step 3: Verify the Installation
Check the installed version of Java to confirm the installation was successful:
java -version
You should see output similar to:
openjdk version "17.0.x" 2023-xx-xx OpenJDK Runtime Environment ... OpenJDK 64-Bit Server VM ...
Step 4: Switch Between Multiple Versions
If you install more than one version of Java, you can select the default version with the alternatives tool:
sudo alternatives --config java
Step 5 (Optional): Configure JAVA_HOME
Some applications require JAVA_HOME. First, find the Java installation path, then export it.
sudo alternatives --config java
export JAVA_HOME=/usr/lib/jvm/java-17-openjdk
