Convertion of Scala typed collection to Java with an unbounded wildcard, etc. Collection<?>

Question

Problem: Need to implement interface from 3rd party Java library in Scala

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Collection<?> getItemPropertyIds()

...

My solution is to use ...<here goes Iterable>.asInstanceOf[java.util.Collection[_]]

 val props:Map[Object,Property] = ...
 override def getItemPropertyIds()=props.keys.asInstanceOf[java.util.Collection[_]]

Is there better solution? Maybe with Predef's implicits?

Answer 1

Create some scala.Iterable, use scala.collection.asJavaCollection() (may be implicitly) to convert to java.util.Collection.

Answer 2

I try also this:

import scala.collection.JavaConversions
...
override def getItemPropertyIds() = JavaConversions.asCollection(props.keys)