A GitHub Action to Export Your Maven Project's Version for Use in Subsequent Steps

This is a fork from joshlong/java-version-export-github-action that adds some new features to the base idea of the upstream:

I saw a great tweet from Bruno Borges about using GitHub Actions to derive the version of Java to be installed by analyzing the pom.xml of the build itself. It seems like a good enough idea, so I put it into practice here. Most of the magic lives in a very tiny JavaScript file, index.js: It'll analyze your Maven pom.xml to determine which version of Java you've configured by having Maven tell it the value of maven.compiler.version. The program then exports the version and the major version of Java as a step output and an environment variable that you could use in later steps.

I really should make this work for Gradle... (Pull requests welcome!)

Usage

This is a basic example of how to use this action in your workflow:

      - uses: BetonQuest/java-version-export-github-action@main
        id: jve

or if you have the java version in another property like the release property:

      - uses: BetonQuest/java-version-export-github-action@main
        id: jve
        with:
          maven-expression: 'maven.compiler.release'

or if you want to use a different Maven command, like ./mvnw, or mvnd or the daemon in the wrapper:

      - uses: BetonQuest/java-version-export-github-action@main
        id: jve
        with:
        maven-command: './mvnw'
        # Or for maven daemon with the --raw-streams option to work properly:
        # maven-command: './mvnw --raw-streams'

Then you can use the exported environment variable:

      - uses: actions/setup-java@v4
        with:
          java-version: ${{ env.JAVA_MAJOR_VERSION }}

or reference the step's output values, like this:

      - uses: actions/setup-java@v4
        with:
          java-version: ${{ steps.jve.outputs.java_major_version }}

Now GitHub Actions will download whatever version of Java you've specified in your Maven pom.xml.