Add support for JavaFX builds

Something like

- uses: actions/setup-java@v1
  with:
    java-version: '1.8'
    javafx: true

I believe Zulu just has ca-fx in the name of jdk versions with JavaFX.

[giltene]

The main driver for us building and providing FX-bundled versions of Zulu JDKs was making sure things work well in transitioning from Oracle JDK 8 to OpenJDK 8. Since Oracle JDK 8 had JavaFX bundled, none of the gradle/maven tooling stuff (as much as I personally use them. recommend them, and am happy/thankful for the community effort put into them) provides a “drop in”, zero changes means for replacing the Oracle JDK. Bundling is there becuase many people’s existing code and workflows assume FX-bundling.

Ironically, one of the most common drivers for people looking for a JavaFX-bundled JDK is not actual JavaFX application use, but “accidental”/unintentional use of some useful classes that happened to be part of JavaFX, but not part of the JDK, and were historically bundled in Oracle JDK 8.

E.g. one of the most popular transitioning problem we’ve run into with plain OpenJDK 8 JDK is that is that OpenJDK 8 is “missing” javafx.util.Pair<K,V>. And yes, it’s just a Pair class, and there are 342 other places you can get a good Pair class from. But that pair class was “part” of Oracle JDK 8, and it just worked there, and it is already in many people’s code, so…

This then continues with OpenJDK 11, where people transitioning existing code from 8 to 11 run into these “missing” FX classes (on top of all their other post-Java-8 trasitioning pain). We’ve run into enough of that in the real world that we chose to regularly provide FX-bundled OpenJDK 11 with Zulu starting with 11.0.3.

[konradpabjan]

Support for JavaFX has been added with #27 being merged in. Big thanks to @giltene ! 🎉

README.md has been updated to reflect the recent changes. As long as you’re using actions/setup-java@v1 then you should be able to use the most recent changes