What's the new way to iterate over a Java Map in Scala 2.8.0?

Question

How does scala.collection.JavaConversions supercede the answers given here:

• http://stackoverflow.com/questions/495741/iterating-over-java-collections-in-scala

(doesn't work because the "jcl" package is gone)

and here

• http://www.eishay.com/2009/05/iterating-over-map-with-scala.html

(doesn't work me in a complicated test which I'll try to boil down and post here later)

The latter is actually a Scala Map question but I think I need to know both answers in order to iterate over a java.util.Map.

Thanks

Answer 1

In 2.8, you import scala.collection.JavaConversions._ and use as a Scala map. Here's an example (in 2.8.0.RC1):

scala> val jmap:java.util.Map[String,String] = new java.util.HashMap[String,String]  
jmap: java.util.Map[String,String] = {}

scala> jmap.put("Hi","there")
res0: String = null

scala> jmap.put("So","long")
res1: String = null

scala> jmap.put("Never","mind")
res2: String = null

scala> import scala.collection.JavaConversions._
import scala.collection.JavaConversions._

scala> jmap.foreach(kv => println(kv._1 + " -> " + kv._2))
Hi -> there
Never -> mind
So -> long

scala> jmap.keys.map(_.toUpperCase).foreach(println)
HI
NEVER
SO

If you specifically want a Scala iterator, use jmap.iterator (after the conversions import).