Set default JAVA_HOME to Java 21 on ubuntu-latest

[martinbonnin]

Tool name

Java

Tool license

GPLv2

Add or update?

• Add
• Update

Desired version

21

Approximate size

0

Brief description of tool

Java 21 is already installed (see https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md#java). This issue is about making 21 the default instead of the current 17.

21 has been the default on macos runners since macos-14

It moves the community forward as Java 25 is just out.

URL for tool's homepage

No response

Provide a basic test case to validate the tool's functionality.

Platforms where you need the tool

• Azure DevOps
• GitHub Actions

Runner images where you need the tool

• Ubuntu 22.04
• Ubuntu 24.04
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26 Arm64
• Windows Server 2019
• Windows Server 2022
• Windows Server 2025

Can this tool be installed during the build?

Tool installation time in runtime

No response

Are you willing to submit a PR?

Sure, #13083

[hemanthmanga]

Hi @martinbonnin, Thank you for bringing this issue to our attention. We will look into this issue and will update you after investigation.

[martinbonnin]

Thanks for the quick reply! I'm not sure what are the compatibility guarantees for runners, is it acceptable to change a default without changing the tag (ubuntu-24)? Or should we wait for the next version? (ubuntu-26 most likely?)

[vidyasagarnimmagaddi]

Hi @martinbonnin , Currently the default version is 17 for Ubuntu-24.04 , to change the default version , an announcement is needed , Will be keeping this feature Open for more customers to request. thanks.