Support JDK 25 (LTS)

[reneleonhardt]

Description:
Support JDK 25 LTS (currently in final release candidate phase).

Justification:
Allow users to try the new LTS ahead of release (for example the removed security manager could break applications).

Are you willing to submit a PR?
Maybe, but 49 open issues and 39 open pull requests don't inspire confidence that all of my work would be allowed to benefit users in a timely fashion...

[gowridurgad]

Hello @reneleonhardt,
Thank you for creating this feature request. We will investigate it and get back to you as soon as we have some feedback.

[osiegmar]

Actually, you can already use Java 25 as long as the vendor (distribution) provides it.

Here is a working example:

on: push

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v5
    - uses: actions/setup-java@v5
      with:
        distribution: 'temurin'
        java-version: '25-ea'

[reneleonhardt]

Thank you for sharing one working distribution!

An equivalent example for Python would be:
https://github.com/actions/setup-python/blob/main/docs/advanced-usage.md#allow-pre-releases

- uses: actions/setup-python@v5
  with:
    python-version: "3.14"
    allow-prereleases: true  # currently resolves to 3.14.0rc2

[hurricup]

@osiegmar not sure how you did this, but I get

  Error: Java setup failed due to network issue or timeout: Early access versions are not supported
  Error: Early access versions are not supported

[osiegmar]

I created this example repository to demonstrate a working setup: https://github.com/osiegmar/use-java25ea-with-github-actions

[hurricup]

Wow, thank you for your time! It does work. Seems that error message need to be updated to clarify that it is not available for the 'oracle' distro, not in general.