Java21 Upgrade (Linux)

This article describes the steps to upgrade Java to version 21 on a Linux machine. It outlines the installation process, configuration updates, and validation steps required to ensure the system uses the correct Java version. The procedure follows a structured approach aligned with standard deployment practices.

Prerequisites

• Linux-based system with root or sudo access

• Access to a package manager (e.g., yum)

• Existing Java installation on the system

• Terminal or command-line access

Steps Involved

Verify Existing Java Version

• Run the following command to check the currently installed Java version:

  java -version

  Sample Reference Screenshot:

  

Install Java 21

• Execute the following command to install Java 21:

  sudo yum install java-21-openjdk-devel -y

  Sample Reference Screenshot:

  

Configure Java Alternatives

• Run the following command to list and configure available Java versions:

  sudo update-alternatives --config java

• From the displayed list, select Java 21 by entering the corresponding number, then press Enter. Sample Reference Screenshot:

  

Validate Java Upgrade

• Verify that the system is using Java 21 by running:

  java -version

  Sample Reference Screenshot:

  

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