Add module-info.java

[kaifox]

As we target java11 now, it would be good to have module support also implemented.

[smac89]

Are you averse to using a higher version of gradle? Like gradle 5.5?

[kaifox]

No I think we are not against using a newer version. I think it is just that nobody up to now took the time to try and see what are the impacts (e.g. on the builds, the release mechanism etc....)

[smac89]

I kinda got started here: https://github.com/smac89/minifx-workbench/tree/java-11
The tests pass for java 8, but one test is failing for java 11.

I was also reading something about modules and stumbled across this concept of a multi-release jar, which you may find interesting:
http://tutorials.jenkov.com/java/modules.html#multi-java-version-module-jar-files

[kaifox]

Dear @smac89, thanks for getting started on this! I will try to take a look ... Do you understand why the one test is failing?

As we mentioned in the pull request, the multi-version jar will not help us, as we need different transient deps for different jdks.

[smac89]

I'm not sure, but it might be an issue with Spring.

spring-projects/spring-boot#13581

[smac89]

Looks like it works now. I didn't push anything yet to my branch

I replaced the default test task with this:

task springTesting(type: Test, group: test.group) {
    testLogging {
        events "passed", "skipped", "failed"
        exceptionFormat "full"
    }
}

Running this new test passes

Not sure what the default test is doing tbh