Access Java enum with same name as static method

[mrckzgl]

Hey, we want to access the enums in this class: https://tinkerpop.apache.org/javadocs/current/core/org/apache/tinkerpop/gremlin/structure/VertexProperty.Cardinality.html from within JRuby.
Before an upgrade of the gremlin jar this worked with: org.apache.tinkerpop.gremlin.structure.VertexProperty::Cardinality::single, but after the upgrade, static methods with the same name as the enums were added to the class (e.g. https://tinkerpop.apache.org/javadocs/current/core/org/apache/tinkerpop/gremlin/structure/VertexProperty.Cardinality.html#single(java.lang.Object). Now if we try to access the enums, JRuby complains about a missing parameter, which indicates that it instead accesses the static method.

How to distinguish between static enum and static method?

[headius]

but after the upgrade

Just to be clear, this happened when you upgraded the gremlin jar, yes?

This is a tricky one; given that they have methods and enum values with the same way, I'm not sure how we can represent both at the same time in JRuby. I'll try to loop in some other JRuby folks to discuss.

[mrckzgl]

Jep exactly, upgrade of gremlin jar. No upgrade of JRuby.

[enebo]

Minimized example:

public enum A {
    one,
    two,
    three,
    Four;

    public static void Four(int i) {}
    public static void one(int i) {}
}

CLASSPATH=. jruby -I. -e 'p Java::A::const_get(:one)'  # boom (lowercase...boooooo)

but

CLASSPATH=. jruby -I. -e 'p Java::A::const_get(:Four)'  # yay

So I think for JavaClasses we relax const_get to allow non-capitalized forms would fix this but also require a little metaprogramming. I think this is ok in this case as it is atypical to use non-const enum values AND happen to have a static method with the same name.

[headius]

I've filed a bug for this in #8188.

A workaround for you for now would be to use reflection to access the enum values:

[] jruby $ cat Blah.java
public enum Blah {
    blah1, blah2;

    public static void blah1() {}
}
[] jruby $ jruby -e 'p Java::Blah.blah1, Java::Blah.blah2'
nil
blah2
[] jruby $ jruby -e 'p Java::Blah.java_class.get_field("blah1").get(nil), Java::Blah.blah2'
blah1
blah2

You should be able to take this further and define Ruby capitalized constants for those values, and just use the constants in your code.

[mrckzgl]

Thanks alot, that works nicely.