How can I call a method defined on a Scala package object from Java? (Scala 2.10.x)

Question

Given a method defined on a (3rd party, so I can't just move it) Scala package object, like so:

package foo

package object bar {
  def doSomething(s: String): String = ???
}

I need to call doSomething from Java code. I know that in general, I can get at a Scala companion object's methods from Java using ScalaObject$.method(). However, the example above compiles to foo.bar.package$.class, and of course Java screams about package being a reserved word.

Is there a way to call this from Java directly?

Régis Jean-Gilles · Accepted Answer · 2015-10-14 10:31:30Z

4

You can access the package object as foo.bar.package$.MODULE$ (note the dollar signs, do not remove them):

foo.bar.package$.MODULE$.doSomething("hello")

answered Oct 14, 2015 at 10:31

Régis Jean-Gilles

32.8k5 gold badges85 silver badges97 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Aleks Sidorenko Jul 18 at 11:26

This works well for example for methods, but if you define some trait in package object you won't be able to reference it from Java this way.

Kyrstellaine · Accepted Answer · 2015-10-14 00:50:56Z

4

The best I can come up with (works, but ugly) is to wrap doSomething in Scala code that's not in a package object, and then call the wrapper from my Java code.

object BarUtil {
  def wrapper(s: String) = foo.bar.doSomething(s)
}

and in Java

public String doIt(String s) {
    return BarUtil$.wrapper(s);
}

answered Oct 14, 2015 at 0:50

Kyrstellaine

4425 silver badges16 bronze badges

Collectives™ on Stack Overflow

How can I call a method defined on a Scala package object from Java? (Scala 2.10.x)

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related