How can I use a Scala singleton object in Java?

Question

I have a Scala object that I need to use in a Java class.

Here's the Scala object

object Person {
  val MALE = "m"
  val FEMALE = "f"
}

How can I use this Scala object in Java?

I have tried the following so far without success (compile errors):

Person.MALE() //returns a String which is useless as I want the actual Person object

possible duplicate of [How can I pass a Scala object reference around in Java?](http://stackoverflow.com/questions/3845737/how-can-i-pass-a-scala-object-reference-around-in-java) — om-nom-nom, Sep 05 '12 at 14:55

score 58 · Accepted Answer · edited May 23 '17 at 12:09

58

Use Person$.MODULE$. See also

Edit: A working example (I checked, it compiles and works): Scala:

object Person {
  val MALE = "m";
}

Java counterpart:

public class Test {
    Person$ myvar = Person$.MODULE$;

    public static void main(String argv[]) {
        System.out.println(new Test().myvar.MALE());
    }
}

edited May 23 '17 at 12:09

Community

1
1

answered Sep 05 '12 at 14:50

Petr

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4

This doesn't really work either. Eclipse tells me: **Person$ cannot be resolved to a variable'code** and the code doesn't compile – user786045 Sep 05 '12 at 15:06
5

@user786045, you need to add an import statement for Person$ manually. Eclipse does not add it automatically on "organize imports". – Hendrik Brummermann Nov 07 '14 at 14:15

score 1 · Answer 2 · answered Apr 19 '17 at 05:27

In case you use a package object, the access is a bit different

Scala:

package my.scala.package

package object Person {
  val MALE = "m";
}

Java counterpart:

public static void main() {
  System.out.println(my.scala.package.Person.package$.MODULE$.MALE);
}

How can I use a Scala singleton object in Java?

2 Answers2

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