CODEWITHSUNDEEP
javascala
Codey McCodeface
Codey McCodeface

Reputation: 3028

Calling a Java static method with generics from Scala

I have a Java method of the form

    public interface JavaInterface< T extends A >{
        static < T extends A > JavaInterface< T > callThis(){
         //I want to call this in scala

        }
    }

In Scala I write

val x = JavaInterface[SomeClass].callThis()

but I get an error telling me it "is not a value". How do I call that static method in Scala?

Upvotes: 0

Views: 183

Answers (2)

user
user

Reputation: 7604

The code you have now assumes JavaInterface is an object with a nilary apply method that returns another object with a callThis() method. For that, your code would have to look something like this (in Scala):

trait JavaInterface[T] {
  def callThis() = println("foobar")
}

object JavaInterface {
  def apply[T <: JavaInterface[T]] = new JavaInterface[T] {}
}

Since you are calling the callThis method on JavaInterface, you need to do JavaInterface.callThis[SomeClass]() instead, giving the type parameter to the method instead of the object (or Java interface) you're calling it on.

Upvotes: 1

Joe
Joe

Reputation: 31087

You want:

val x = JavaInterface.callThis[SomeClass]()

It's the method, not the type, that's parameterised for static methods.

Upvotes: 6

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