Supports running on Java Early Access versions

[jqno]

I'm trying to run my unit tests on an Early Access version of Java 11 (gotta be prepared 😉), and my ArchUnit test fails while attempting to parse the version string:

java.lang.ExceptionInInitializerError
Caused by: java.lang.NumberFormatException: For input string: "11-ea"

This PR should fix that.

[jqno]

(I hope it's ok that I used a secondary e-mail address in the sign-off, I don't like leaving my main one in public places on the internet. I do answer this one.)

[codecholeric]

Thanks a lot for your contribution 😃
I've made a little adjustment, by just matching the first group of digits (doing [^.] was obviously a little short-sighted 😉). It's kind of what the method name (parseFirstGroupOfJavaVersion) suggests anyway.
Now at least either the matches and the parseInt should work, or the matches should already fail.
How fast do you need this released? I'm gonna release 0.9.0 within the next 2-3 weeks I think, if this patch is vitally important for you, I would do a minor release this weekend.

[jqno]

Thanks for the quick response! The adjustment seems like a good idea. A release in the next 2-3 weeks is totally fine for me.

[codecholeric]

PS: It's hacky 😉, but as a workaround you could probably wrap the class import into sth. like

try {
    System.setProperty("java.version", "11");
    classFileImporter.import... //
} finally {
    System.setProperty("java.version", oldVersion);
}

[jqno]

I just noticed that the release has taken place. Just wanted to confirm that it does indeed work. Thanks!

(Also: looking forward to seeing your talk at JavaZone ;) )

[codecholeric]

Glad it works!! Looking forward to giving my talk 😃