How to I override a Java varargs method in Scala?

Question

I have a method defined in Java like:

void foo(int x, Thing... things)

I need to override that in Scala, but both of these give errors:

override def foo(x: Int, things: Thing*)
override def foo(x: Int, things: Array[Thing])

The errors refer to <repeated...> but I don't know what that is.

Update

Ugg... nevermind. I'm in 2.10.0, and I had mis-typed something and didn't have a method body. Then I got confused by this error message, which still seems a odd to me. In SBT:

> compile
[info] Compiling 1 Scala source to [...]/target/scala-2.10/classes...
[error] [...]/src/main/scala/Translator.scala:41: class MyMethodVisitor needs to be abstract, since method visitTableSwitchInsn is not defined
[error] (Note that org.objectweb.asm.Label* does not match <repeated...>[org.objectweb.asm.Label])
[error]   class MyMethodVisitor extends MethodVisitor (Opcodes.ASM4) {
[error]         ^

The problem is that my visitTableSwitchInsn simply lacks a body, but the error suggests that the problem is the type of the varargs parameter.

This looks like you may be seeing a bug that was fixed in 2.10. If you think not, can you give your version number and a little more context? — Travis Brown
– Travis Brown, Commented Jan 15, 2013 at 23:29
Thanks. I was seeing a bug in my brain, plus a confusing error message (which I've added to the question). — Rob N
– Rob N, Commented Jan 16, 2013 at 1:38

Randall Schulz · Accepted Answer · 2013-01-15 23:50:35Z

1

Java:

package rrs.scribble;

public
class   VA1
{
    public int va1(int... ints) {
        return ints.length;
    }
}

Scala:

package rrs.scribble

class   VA1S
extends VA1
{
  override
  def va1(ints: Int*): Int =
    ints.length * 2
}

SBT:

> ~compile
[info] Compiling 1 Scala source and 1 Java source to …/scribble/target/scala-2.10/classes...
[success] Total time: 4 s, completed Jan 15, 2013 3:48:14 PM
1. Waiting for source changes... (press enter to interrupt)

This is Scala 2.10, which is consistent with @TravisBrown's comment.

answered Jan 15, 2013 at 23:50

Randall Schulz

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1 Comment

Rob N Over a year ago

Thanks. When I returned after a break, I saw my obvious code mistake. :| My method simply lacked a body. Maybe the error message could be better. I updated the question.

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