How to pass Scala Seq to a Java varargs

Question

I have an existing Java method like this:

public static MyJavaClass javaFunc(String name, long... values) {
    ...
}

and I need to call it from Scala with this:

val idList: Seq[Long] = Seq(1L, 2L, 3L)

MyJavaClass.javaFunc("hello", idList)

but it ends up invoking the toString method on the idList parameter. I've tried the following to no avail:

MyJavaClass.javaFunc("hello", idList:_*)

which causes compile error:

no `: _*' annotation allowed here (such annotations are only allowed in arguments to *-parameters)

How can I pass the argument?

Answer 1

// java class
public class MyJavaClass {
    public static void javaFunc(String name, long ...values) {
        for (long i: values)
            System.out.print(i + " ");
        System.out.println();
    }
}

//scala class
object Y {
  def main(args: Array[String]): Unit = {
    val idList: Seq[Long] = Seq(1L, 2L, 3L)
    MyJavaClass.javaFunc("hello", idList: _*)
  }
}

it is working like this for me