Static verification support

[nedtwigg]

I'm writing java-only code, and I want it to be friendly to Kotlin users. I also would like the same Kotlin non-null semantics in Java, as much as possible.

I would like to apply [SpotBugs, Checker Framework, whatever], and have it yell at me if I'm assigning null to a field or variable anywhere that wasn't annotated as @OrNull.

Do you have any experience / recommendations for using your annotations with other tools? I really enjoyed your https://dzone.com/articles/when-to-use-jsr-305-for-nullability-in-java article, thanks for digging in and sorting through the various efforts!

[tlinkowski]

Hi Ned, thanks for your kind words!

I agree it would be very useful to have a simple and universal way of enforcing the nullability contract at compile-time.

I haven't truly explored this area so far, but I gave it a cursory look right now, and here's what I found...

SpotBugs

I wasn't able to find out in the docs if SpotBugs honors custom JSR-305-based nullability annotations (i.e. @NonNullPackage and @NullOr). Perhaps it can handle them out of the box like IntelliJ and Kotlin compiler (especially since SpotBugs is a successor of FindBugs, which relied on JSR-305). I guess you'd need to run SpotBugs and verify this.

Theoretically, one could also implement a custom SpotBugs plugin for it, but it'd seem an overkill to me.

Checker Framework

Checker Framework clearly supports non-meta JSR-305 annotations like @javax.annotation.Nonnull.

However, I wasn't able to find out in the docs if it also supports meta JSR-305 annotations (@TypeQualifierDefault or @TypeQualifierNickname, which I used to define my annotations). So again, I guess you'd need to try it out.

IDEA Inspection Plugin

If you're using Gradle, one option that might work as expected (although I haven't tried it) could be IntelliJ IDEA inspection plugin (still in the "incubator", though). Since IntelliJ honors my annotations out of the box, simply turning on some nullable inspections should suffice.

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Hope it helps.