Scala 2.8.1隐式转换为java.util.List <java.util.Map<String, Object> &gt;

Question

I have a Scala data structure created with the following:

List(Map[String, Anyref]("a" -> someFoo, "b" -> someBar))

I would like to implicitly convert it (using scala.collection.JavaConversions or scala.collection.JavaConverters ) to a java.util.List<java.util.Map<String, Object>> to be passed the a Java method that expects the latter.

Is this possible?

I have already created the following method that does it, but was wondering if it can be done automatically by the compiler?

import scala.collection.JavaConversions._
def convertToJava(listOfMaps: List[Map[String, AnyRef]]):
  java.util.List[java.util.Map[String, Object]] = {
  asJavaList(listOfMaps.map(asJavaMap(_)))
}

Answer 1

How about writing

implicit def convertToJava...

?

Answer 2

You don't want this kind of multilevel conversion happening by magic. You can improve a little on your own conversion though, at least aesthetically.

import java.{ util => ju }
implicit def convert[K, V](xs: List[Map[K, V]]): ju.List[ju.Map[K, V]] = xs map (x => x: ju.Map[K, V])