I’m working with a java library that does somethin...

# getting-started

[bbaldino]

I’m working with a java library that does something like this:

class Foo {
    public static Foo.Builder Builder() { ... }
    public static class Builder { 
        public Builder() { ... }
    }
}

and i’m trying to call it from kotlin like:

Foo.Builder()
...

but i get complaints about ambiguity…i think because the helper type in Foo matches the class name (and therefore the constructor) exactly. does anyone know if there’s a way to disambiguate between the two from kotlin?

[bbaldino]

unfortunately out of my control 😕

[Ruckus]

Sorry, I misread 🙂

[bbaldino]

i did mutter some curses at the lib developers, as is tradition.

[Ruckus]

Always a recommended first step.

[bbaldino]

calling this code from java does work, which is surprising. i’d think it would be problematic there, too.

[ephemient]

hmm. you can sorta disambiguate in one way,

Foo.Builder::class

but that doesn't really help

[bbaldino]

but i’m in a pure kotlin project now and would hate to open the java gates for that

[ephemient]

Java requires a new keyword to call the constructor while Kotlin treats them all as callables in the same namespace

[bbaldino]

Ah ha…good catch

[bbaldino]

hmm…i wonder if with ::class i could grab the constructor and call it like that. ugly, but workable maybe

[ephemient]

if you don't mind importing kotlin.reflect and bypassing the function, you can

Foo.Builder::class.createInstance()

[ephemient]

doing the same for the function is probably doable, but it would have to look more like

Foo::class.declaredFunctions.single { it.name == "Builder" }.call() as Foo.Builder

[bbaldino]

ah yeah, i’ll probably just do that for now

[bbaldino]

createInstance is probably workable

[bbaldino]

Ugh…so actually the real Foo class has generics, so I can’t use ::class 😕

[bbaldino]

I thought a typealias might work, but it looks like the static functions of the aliased type don’t resolve on the typealias?

[bbaldino]

maybe i’ll just have to write a subclass or wrapper class

[bbaldino]

ah, i take that back…the typealias did work