Parse Java distribution from .sdkmanrc

[mlschechter]

Description:
Given that the action now supports reading the Java version from the .sdkmanrc file, it would be advantageous to read a default distribution from that file as well. SDKMan uses distinct suffixes for each distribution to simplify mapping.

Justification:
Removes the need for users to duplicate the distribution information into their workflow.

Are you willing to submit a PR?
Maybe? Depends on the level of effort :)

[aparnajyothi-y]

Hello @mlschechter, Thank you for creating this issue and we will get back to you once we have some feedback on this :)

[lukaszgyg]

I've implemented this feature in PR #975.

Why This Feature Matters

When using .sdkmanrc, the distribution information is already present in the file format itself (e.g., java=21.0.5-tem where tem indicates Temurin). Currently, users must redundantly specify this in their workflow:

Current requirement (redundant):

- uses: actions/setup-java@main
  with:
    distribution: temurin  # Duplicates information from .sdkmanrc
    java-version-file: .sdkmanrc

.sdkmanrc already contains:

java=21.0.5-tem  # "tem" already indicates Temurin

Value Proposition

1. Eliminates Redundancy: The distribution parameter becomes unnecessary when .sdkmanrc already specifies it
2. Single Source of Truth: Java configuration lives entirely in .sdkmanrc
3. Consistency: Local development (SDKMAN) and CI/CD use identical configuration
4. Simplified Workflows: One less parameter to maintain and keep in sync

With this feature:

- uses: actions/setup-java@main
  with:
    java-version-file: .sdkmanrc  # That's it!

The implementation is backward compatible - if .sdkmanrc doesn't include a distribution suffix, the distribution parameter is still required.

[lukaszgyg]

Implemented in PR #975. The PR now parses supported SDKMAN distribution suffixes from .sdkmanrc, including the mapping fixes and test coverage discussed in review.

[michael-schechter-simspace]

@lukaszgyg - Thanks for the implementation; is there any information on when this will be merged and released?

[lukaszgyg]

Unfortunately no :-(
@aparnajyothi-y how we can trigger the review process for #975

[brunoborges]

Linking implementation: this is being addressed by PR #975 (distribution detection from .sdkmanrc). Tracking it there — this issue should auto-close when #975 merges.

[brunoborges]

Tracked under the epic #1048 (infer Java version/distribution from project files), which groups the related file-based detection requests for consistent design. This issue stays open as the specific sub-request.