/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2006-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://www.scala-lang.org/           **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala.collection

/**   A collection of implicit conversions supporting interoperability between
 *    Scala and Java collections.
 *
 *    The following conversions are supported:
 *{{{
 *    scala.collection.Iterable <=> java.lang.Iterable
 *    scala.collection.Iterable <=> java.util.Collection
 *    scala.collection.Iterator <=> java.util.{ Iterator, Enumeration }
 *    scala.collection.mutable.Buffer <=> java.util.List
 *    scala.collection.mutable.Set <=> java.util.Set
 *    scala.collection.mutable.Map <=> java.util.{ Map, Dictionary }
 *    scala.collection.mutable.ConcurrentMap <=> java.util.concurrent.ConcurrentMap
 *}}}
 *    In all cases, converting from a source type to a target type and back
 *    again will return the original source object, eg.
 *
 *{{{
 *    import scala.collection.JavaConversions._
 * 
 *    val sl = new scala.collection.mutable.ListBuffer[Int]
 *    val jl : java.util.List[Int] = sl
 *    val sl2 : scala.collection.mutable.Buffer[Int] = jl
 *    assert(sl eq sl2)
 *}}}
 *  In addition, the following one way conversions are provided:
 *
 *{{{
 *    scala.collection.Seq         => java.util.List
 *    scala.collection.mutable.Seq => java.util.List
 *    scala.collection.Set         => java.util.Set
 *    scala.collection.Map         => java.util.Map
 *    java.util.Properties         => scala.collection.mutable.Map[String, String]
 *}}}
 * 
 *  @author Miles Sabin
 *  @author Martin Odersky
 *  @since  2.8
 */
object JavaConversions {
  // Note to implementors: the cavalcade of deprecated methods herein should
  // serve as a warning to any who follow: don't overload implicit methods.
  
  import java.{ lang => jl, util => ju }
  import java.util.{ concurrent => juc }

  // Scala => Java

  /**
   * Implicitly converts a Scala Iterator to a Java Iterator.
   * The returned Java Iterator is backed by the provided Scala
   * Iterator and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Iterator was previously obtained from an implicit or
   * explicit call of asIterator(java.util.Iterator) then the original
   * Java Iterator will be returned.
   * 
   * @param i The Iterator to be converted.
   * @return A Java Iterator view of the argument.
   */
  implicit def asJavaIterator[A](i : Iterator[A]): ju.Iterator[A] = i match {
    case JIteratorWrapper(wrapped) => wrapped
    case _ => IteratorWrapper(i)
  }

  @deprecated("use asJavaIterator instead", "2.8.1")
  def asIterator[A](i : Iterator[A]): ju.Iterator[A] = asJavaIterator[A](i)

  /**
   * Implicitly converts a Scala Iterator to a Java Enumeration.
   * The returned Java Enumeration is backed by the provided Scala
   * Iterator and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Iterator was previously obtained from an implicit or
   * explicit call of asIterator(java.util.Enumeration) then the
   * original Java Enumeration will be returned.
   * 
   * @param i The Iterator to be converted.
   * @return A Java Enumeration view of the argument.
   */
  implicit def asJavaEnumeration[A](i : Iterator[A]): ju.Enumeration[A] = i match {
    case JEnumerationWrapper(wrapped) => wrapped
    case _ => IteratorWrapper(i)
  }

  @deprecated("use asJavaEnmeration instead", "2.8.1")
  def asEnumeration[A](i : Iterator[A]): ju.Enumeration[A] = asJavaEnumeration[A](i)

  /**
   * Implicitly converts a Scala Iterable to a Java Iterable.
   * The returned Java Iterable is backed by the provided Scala
   * Iterable and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Iterable was previously obtained from an implicit or
   * explicit call of asIterable(java.lang.Iterable) then the original
   * Java Iterable will be returned.
   * 
   * @param i The Iterable to be converted.
   * @return A Java Iterable view of the argument.
   */
  implicit def asJavaIterable[A](i : Iterable[A]): jl.Iterable[A] = i match {
    case JIterableWrapper(wrapped) => wrapped
    case _ => IterableWrapper(i)
  }

  @deprecated("use asJavaIterable instead", "2.8.1")
  def asIterable[A](i : Iterable[A]): jl.Iterable[A] = asJavaIterable[A](i)

  /**
   * Implicitly converts a Scala Iterable to an immutable Java
   * Collection.
   * 
   * If the Scala Iterable was previously obtained from an implicit or
   * explicit call of asSizedIterable(java.util.Collection) then the original
   * Java Collection will be returned.
   * 
   * @param i The SizedIterable to be converted.
   * @return A Java Collection view of the argument.
   */
  implicit def asJavaCollection[A](i : Iterable[A]): ju.Collection[A] = i match {
    case JCollectionWrapper(wrapped) => wrapped
    case _ => new IterableWrapper(i)
  }
  
  @deprecated("use asJavaCollection instead", "2.8.1")
  def asCollection[A](i : Iterable[A]): ju.Collection[A] = asJavaCollection[A](i)

  /**
   * Implicitly converts a Scala mutable Buffer to a Java List.
   * The returned Java List is backed by the provided Scala
   * Buffer and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Buffer was previously obtained from an implicit or
   * explicit call of asBuffer(java.util.List) then the original
   * Java List will be returned.
   * 
   * @param b The Buffer to be converted.
   * @return A Java List view of the argument.
   */
  implicit def bufferAsJavaList[A](b : mutable.Buffer[A]): ju.List[A] = b match {
    case JListWrapper(wrapped) => wrapped
    case _ => new MutableBufferWrapper(b)
  }
  @deprecated("use bufferAsJavaList instead", "2.9.0")
  def asJavaList[A](b : mutable.Buffer[A]): ju.List[A] = bufferAsJavaList[A](b)
  @deprecated("use bufferAsJavaList instead", "2.8.1")
  def asList[A](b : mutable.Buffer[A]): ju.List[A] = bufferAsJavaList[A](b)

  /**
   * Implicitly converts a Scala mutable Seq to a Java List.
   * The returned Java List is backed by the provided Scala
   * Seq and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Seq was previously obtained from an implicit or
   * explicit call of asSeq(java.util.List) then the original
   * Java List will be returned.
   * 
   * @param b The Seq to be converted.
   * @return A Java List view of the argument.
   */
  implicit def mutableSeqAsJavaList[A](b : mutable.Seq[A]): ju.List[A] = b match {
    case JListWrapper(wrapped) => wrapped
    case _ => new MutableSeqWrapper(b)
  }
  @deprecated("use mutableSeqAsJavaList instead", "2.9.0")
  def asJavaList[A](b : mutable.Seq[A]): ju.List[A] = mutableSeqAsJavaList[A](b)
  @deprecated("use mutableSeqAsJavaList instead", "2.8.1")
  def asList[A](b : mutable.Seq[A]): ju.List[A] = mutableSeqAsJavaList[A](b)

  /**
   * Implicitly converts a Scala Seq to a Java List.
   * The returned Java List is backed by the provided Scala
   * Seq and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Seq was previously obtained from an implicit or
   * explicit call of asSeq(java.util.List) then the original
   * Java List will be returned.
   * 
   * @param b The Seq to be converted.
   * @return A Java List view of the argument.
   */
  implicit def seqAsJavaList[A](b : Seq[A]): ju.List[A] = b match {
    case JListWrapper(wrapped) => wrapped
    case _ => new SeqWrapper(b)
  }

  @deprecated("use seqAsJavaList instead", "2.9.0")
  def asJavaList[A](b : Seq[A]): ju.List[A] = seqAsJavaList[A](b)
  @deprecated("use seqAsJavaList instead", "2.8.1")
  def asList[A](b : Seq[A]): ju.List[A] = seqAsJavaList[A](b)

  /**
   * Implicitly converts a Scala mutable Set to a Java Set.
   * The returned Java Set is backed by the provided Scala
   * Set and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Set was previously obtained from an implicit or
   * explicit call of asSet(java.util.Set) then the original
   * Java Set will be returned.
   * 
   * @param s The Set to be converted.
   * @return A Java Set view of the argument.
   */
  implicit def mutableSetAsJavaSet[A](s : mutable.Set[A]): ju.Set[A] = s match {
    case JSetWrapper(wrapped) => wrapped
    case _ => new MutableSetWrapper(s)
  }

  @deprecated("use mutableSetAsJavaSet instead", "2.9.0")
  def asJavaSet[A](s : mutable.Set[A]): ju.Set[A] = mutableSetAsJavaSet[A](s)
  @deprecated("use mutableSetAsJavaSet instead", "2.8.1")
  def asSet[A](s : mutable.Set[A]): ju.Set[A] = mutableSetAsJavaSet[A](s)

  /**
   * Implicitly converts a Scala Set to a Java Set.
   * The returned Java Set is backed by the provided Scala
   * Set and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Set was previously obtained from an implicit or
   * explicit call of asSet(java.util.Set) then the original
   * Java Set will be returned.
   * 
   * @param s The Set to be converted.
   * @return A Java Set view of the argument.
   */
  implicit def setAsJavaSet[A](s: Set[A]): ju.Set[A] = s match {
    case JSetWrapper(wrapped) => wrapped
    case _ => new SetWrapper(s)
  }

  @deprecated("use setAsJavaSet instead", "2.9.0")
  def asJavaSet[A](s: Set[A]): ju.Set[A] = setAsJavaSet[A](s)
  @deprecated("use setAsJavaSet instead", "2.8.1")
  def asSet[A](s : Set[A]): ju.Set[A] = setAsJavaSet[A](s)

  /**
   * Implicitly converts a Scala mutable Map to a Java Map.
   * The returned Java Map is backed by the provided Scala
   * Map and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Map was previously obtained from an implicit or
   * explicit call of asMap(java.util.Map) then the original
   * Java Map will be returned.
   * 
   * @param m The Map to be converted.
   * @return A Java Map view of the argument.
   */
  implicit def mutableMapAsJavaMap[A, B](m : mutable.Map[A, B]): ju.Map[A, B] = m match {
    //case JConcurrentMapWrapper(wrapped) => wrapped
    case JMapWrapper(wrapped) => wrapped
    case _ => new MutableMapWrapper(m)
  }

  @deprecated("use mutableMapAsJavaMap instead", "2.9.0")
  def asJavaMap[A, B](m : mutable.Map[A, B]): ju.Map[A, B] = mutableMapAsJavaMap[A, B](m)
  @deprecated("use mutableMapAsJavaMap instead", "2.8.1")
  def asMap[A, B](m : mutable.Map[A, B]): ju.Map[A, B] = mutableMapAsJavaMap[A, B](m)

  /**
   * Implicitly converts a Scala mutable Map to a Java Dictionary.
   * The returned Java Dictionary is backed by the provided Scala
   * Dictionary and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Dictionary was previously obtained from an implicit or
   * explicit call of asMap(java.util.Dictionary) then the original
   * Java Dictionary will be returned.
   * 
   * @param m The Map to be converted.
   * @return A Java Dictionary view of the argument.
   */
  implicit def asJavaDictionary[A, B](m : mutable.Map[A, B]): ju.Dictionary[A, B] = m match {
    //case JConcurrentMapWrapper(wrapped) => wrapped
    case JDictionaryWrapper(wrapped) => wrapped
    case _ => new DictionaryWrapper(m)
  }

  @deprecated("use asJavaDictionary instead", "2.8.1")
  def asDictionary[A, B](m : mutable.Map[A, B]): ju.Dictionary[A, B] = asJavaDictionary[A, B](m)

  /**
   * Implicitly converts a Scala Map to a Java Map.
   * The returned Java Map is backed by the provided Scala
   * Map and any side-effects of using it via the Java interface will
   * be visible via the Scala interface and vice versa.
   * 
   * If the Scala Map was previously obtained from an implicit or
   * explicit call of asMap(java.util.Map) then the original
   * Java Map will be returned.
   * 
   * @param m The Map to be converted.
   * @return A Java Map view of the argument.
   */
  implicit def mapAsJavaMap[A, B](m : Map[A, B]): ju.Map[A, B] = m match {
    //case JConcurrentMapWrapper(wrapped) => wrapped
    case JMapWrapper(wrapped) => wrapped
    case _ => new MapWrapper(m)
  }
  
  @deprecated("use mapAsJavaMap instead", "2.9.0")
  def asJavaMap[A, B](m : Map[A, B]): ju.Map[A, B] = mapAsJavaMap[A, B](m)
  @deprecated("use mapAsJavaMap instead", "2.8.1")
  def asMap[A, B](m : Map[A, B]): ju.Map[A, B] = mapAsJavaMap[A, B](m)

  /**
   * Implicitly converts a Scala mutable `ConcurrentMap` to a Java `ConcurrentMap`.
   * The returned Java `ConcurrentMap` is backed by the provided Scala `ConcurrentMap`
   * and any side-effects of using it via the Java interface will be visible
   * via the Scala interface and vice versa.
   * 
   * If the Scala ConcurrentMap was previously obtained from an implicit or
   * explicit call of asConcurrentMap(java.util.concurrect.ConcurrentMap) then the original
   * Java ConcurrentMap will be returned.
   * 
   * @param m The ConcurrentMap to be converted.
   * @return A Java ConcurrentMap view of the argument.
   */
  implicit def asJavaConcurrentMap[A, B](m: mutable.ConcurrentMap[A, B]): juc.ConcurrentMap[A, B] = m match {
    case JConcurrentMapWrapper(wrapped) => wrapped
    case _ => new ConcurrentMapWrapper(m)
  }

  @deprecated("use asJavaConcurrentMap instead", "2.8.1")
  def asConcurrentMap[A, B](m: mutable.ConcurrentMap[A, B]): juc.ConcurrentMap[A, B] = asJavaConcurrentMap[A, B](m)

  // Java => Scala
  
  /**
   * Implicitly converts a Java Iterator to a Scala Iterator.
   * The returned Scala Iterator is backed by the provided Java
   * Iterator and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java Iterator was previously obtained from an implicit or
   * explicit call of asIterator(scala.collection.Iterator) then the original
   * Scala Iterator will be returned.
   * 
   * @param i The Iterator to be converted.
   * @return A Scala Iterator view of the argument.
   */
  implicit def asScalaIterator[A](i : ju.Iterator[A]): Iterator[A] = i match {
    case IteratorWrapper(wrapped) => wrapped
    case _ => JIteratorWrapper(i)
  }

  @deprecated("use asScalaIterator instead", "2.8.1")
  def asIterator[A](i : ju.Iterator[A]): Iterator[A] = asScalaIterator[A](i)
  
  /**
   * Implicitly converts a Java Enumeration to a Scala Iterator.
   * The returned Scala Iterator is backed by the provided Java
   * Enumeration and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java Enumeration was previously obtained from an implicit or
   * explicit call of enumerationAsScalaIterator(scala.collection.Iterator) then the
   * original Scala Iterator will be returned.
   * 
   * @param i The Enumeration to be converted.
   * @return A Scala Iterator view of the argument.
   */
  implicit def enumerationAsScalaIterator[A](i : ju.Enumeration[A]): Iterator[A] = i match {
    case IteratorWrapper(wrapped) => wrapped
    case _ => JEnumerationWrapper(i)
  }
  
  @deprecated("use enumerationAsScalaIterator instead", "2.8.1")
  def asIterator[A](i : ju.Enumeration[A]): Iterator[A] = enumerationAsScalaIterator[A](i)

  /**
   * Implicitly converts a Java Iterable to a Scala Iterable.
   * The returned Scala Iterable is backed by the provided Java
   * Iterable and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java Iterable was previously obtained from an implicit or
   * explicit call of iterableAsScalaIterable(scala.collection.Iterable) then the original
   * Scala Iterable will be returned.
   * 
   * @param i The Iterable to be converted.
   * @return A Scala Iterable view of the argument.
   */
  implicit def iterableAsScalaIterable[A](i : jl.Iterable[A]): Iterable[A] = i match {
    case IterableWrapper(wrapped) => wrapped
    case _ => JIterableWrapper(i)
  }
  
  @deprecated("use iterableAsScalaIterable instead", "2.9.0")
  def asScalaIterable[A](i : jl.Iterable[A]): Iterable[A] = iterableAsScalaIterable[A](i)
  @deprecated("use iterableAsScalaIterable instead", "2.8.1")
  def asIterable[A](i : jl.Iterable[A]): Iterable[A] = iterableAsScalaIterable[A](i)

  /**
   * Implicitly converts a Java Collection to an Scala Iterable.
   * 
   * If the Java Collection was previously obtained from an implicit or
   * explicit call of collectionAsScalaIterable(scala.collection.SizedIterable) then
   * the original Scala Iterable will be returned.
   * 
   * @param i The Collection to be converted.
   * @return A Scala Iterable view of the argument.
   */
  implicit def collectionAsScalaIterable[A](i : ju.Collection[A]): Iterable[A] = i match {
    case IterableWrapper(wrapped) => wrapped
    case _ => JCollectionWrapper(i)
  }
  @deprecated("use collectionAsScalaIterable instead", "2.9.0")
  def asScalaIterable[A](i : ju.Collection[A]): Iterable[A] = collectionAsScalaIterable[A](i)
  @deprecated("use collectionAsScalaIterable instead", "2.8.1")
  def asIterable[A](i : ju.Collection[A]): Iterable[A] = collectionAsScalaIterable[A](i)

  /**
   * Implicitly converts a Java List to a Scala mutable Buffer.
   * The returned Scala Buffer is backed by the provided Java
   * List and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java List was previously obtained from an implicit or
   * explicit call of asScalaBuffer(scala.collection.mutable.Buffer) then the original
   * Scala Buffer will be returned.
   * 
   * @param l The List to be converted.
   * @return A Scala mutable Buffer view of the argument.
   */
  implicit def asScalaBuffer[A](l : ju.List[A]): mutable.Buffer[A] = l match {
    case MutableBufferWrapper(wrapped) => wrapped
    case _ =>new JListWrapper(l)
  }

  @deprecated("use asScalaBuffer instead", "2.8.1")
  def asBuffer[A](l : ju.List[A]): mutable.Buffer[A] = asScalaBuffer[A](l)

  /**
   * Implicitly converts a Java Set to a Scala mutable Set.
   * The returned Scala Set is backed by the provided Java
   * Set and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java Set was previously obtained from an implicit or
   * explicit call of asScalaSet(scala.collection.mutable.Set) then the original
   * Scala Set will be returned.
   * 
   * @param s The Set to be converted.
   * @return A Scala mutable Set view of the argument.
   */
  implicit def asScalaSet[A](s : ju.Set[A]): mutable.Set[A] = s match {
    case MutableSetWrapper(wrapped) => wrapped
    case _ =>new JSetWrapper(s)
  }
  
  @deprecated("use asScalaSet instead", "2.8.1")
  def asSet[A](s : ju.Set[A]): mutable.Set[A] = asScalaSet[A](s)

  /**
   * Implicitly converts a Java Map to a Scala mutable Map.
   * The returned Scala Map is backed by the provided Java
   * Map and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java Map was previously obtained from an implicit or
   * explicit call of mapAsScalaMap(scala.collection.mutable.Map) then the original
   * Scala Map will be returned.
   * 
   * @param m The Map to be converted.
   * @return A Scala mutable Map view of the argument.
   */
  implicit def mapAsScalaMap[A, B](m : ju.Map[A, B]): mutable.Map[A, B] = m match {
    //case ConcurrentMapWrapper(wrapped) => wrapped
    case MutableMapWrapper(wrapped) => wrapped
    case _ => new JMapWrapper(m)
  }

  @deprecated("use mapAsScalaMap instead", "2.9.0")
  def asScalaMap[A, B](m : ju.Map[A, B]): mutable.Map[A, B] = mapAsScalaMap[A, B](m)
  @deprecated("use mapAsScalaMap instead", "2.8.1")
  def asMap[A, B](m : ju.Map[A, B]): mutable.Map[A, B] = mapAsScalaMap[A, B](m)

  /**
   * Implicitly converts a Java ConcurrentMap to a Scala mutable ConcurrentMap.
   * The returned Scala ConcurrentMap is backed by the provided Java
   * ConcurrentMap and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * If the Java ConcurrentMap was previously obtained from an implicit or
   * explicit call of asConcurrentMap(scala.collection.mutable.ConcurrentMap) then the original
   * Scala ConcurrentMap will be returned.
   * 
   * @param m The ConcurrentMap to be converted.
   * @return A Scala mutable ConcurrentMap view of the argument.
   */
  implicit def asScalaConcurrentMap[A, B](m: juc.ConcurrentMap[A, B]): mutable.ConcurrentMap[A, B] = m match {
    case cmw: ConcurrentMapWrapper[a, b] => cmw.underlying
    case _ => new JConcurrentMapWrapper(m)
  }
  
  @deprecated("use asScalaConcurrentMap instead", "2.8.1")
  def asConcurrentMap[A, B](m: juc.ConcurrentMap[A, B]): mutable.ConcurrentMap[A, B] = asScalaConcurrentMap[A, B](m)

  /**
   * Implicitly converts a Java Dictionary to a Scala mutable Map[String, String].
   * The returned Scala Map[String, String] is backed by the provided Java
   * Dictionary and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * @param m The Dictionary to be converted.
   * @return A Scala mutable Map[String, String] view of the argument.
   */
  implicit def dictionaryAsScalaMap[A, B](p: ju.Dictionary[A, B]): mutable.Map[A, B] = p match {
    case DictionaryWrapper(wrapped) => wrapped
    case _ => new JDictionaryWrapper(p)
  }

  @deprecated("use dictionaryAsScalaMap instead", "2.8.1")
  def asMap[A, B](p: ju.Dictionary[A, B]): mutable.Map[A, B] = dictionaryAsScalaMap[A, B](p)

  /**
   * Implicitly converts a Java Properties to a Scala mutable Map[String, String].
   * The returned Scala Map[String, String] is backed by the provided Java
   * Properties and any side-effects of using it via the Scala interface will
   * be visible via the Java interface and vice versa.
   * 
   * @param m The Properties to be converted.
   * @return A Scala mutable Map[String, String] view of the argument.
   */
  implicit def propertiesAsScalaMap(p: ju.Properties): mutable.Map[String, String] = p match {
    case _ => new JPropertiesWrapper(p)
  }

  @deprecated("use propertiesAsScalaMap instead", "2.9.0")
  def asScalaMap(p: ju.Properties): mutable.Map[String, String] = propertiesAsScalaMap(p)
  @deprecated("use propertiesAsScalaMap instead", "2.8.1")
  def asMap(p: ju.Properties): mutable.Map[String, String] = propertiesAsScalaMap(p)

  // Private implementations (shared by JavaConverters) ...
  
  trait IterableWrapperTrait[A] extends ju.AbstractCollection[A] {
    val underlying: Iterable[A]
    def size = underlying.size
    override def iterator = IteratorWrapper(underlying.iterator)
    override def isEmpty = underlying.isEmpty
  }

  case class IteratorWrapper[A](underlying : Iterator[A]) extends ju.Iterator[A] with ju.Enumeration[A] {
    def hasNext = underlying.hasNext
    def next() = underlying.next
    def hasMoreElements = underlying.hasNext
    def nextElement() = underlying.next
    def remove() = throw new UnsupportedOperationException
  }

  class ToIteratorWrapper[A](underlying : Iterator[A]) {
    def asJava = new IteratorWrapper(underlying)
  }

  case class JIteratorWrapper[A](underlying : ju.Iterator[A]) extends Iterator[A] {
    def hasNext = underlying.hasNext
    def next() = underlying.next
  }

  case class JEnumerationWrapper[A](underlying : ju.Enumeration[A]) extends Iterator[A] {
    def hasNext = underlying.hasMoreElements
    def next() = underlying.nextElement
  }

  case class IterableWrapper[A](underlying : Iterable[A])
                extends ju.AbstractCollection[A]
                   with IterableWrapperTrait[A] { }

  case class JIterableWrapper[A](underlying : jl.Iterable[A]) extends Iterable[A] {
    def iterator = underlying.iterator
    def newBuilder[B] = new mutable.ArrayBuffer[B]
  }

  case class JCollectionWrapper[A](underlying : ju.Collection[A]) extends Iterable[A] {
    def iterator = underlying.iterator
    override def size = underlying.size
    override def isEmpty = underlying.isEmpty
    def newBuilder[B] = new mutable.ArrayBuffer[B]
  }
  
  case class SeqWrapper[A](underlying : Seq[A]) extends ju.AbstractList[A] with IterableWrapperTrait[A] {
    def get(i : Int) = underlying(i)
  }
  
  case class MutableSeqWrapper[A](underlying : mutable.Seq[A]) extends ju.AbstractList[A] with IterableWrapperTrait[A] {
    def get(i : Int) = underlying(i)
    override def set(i : Int, elem: A) = { val p = underlying(i) ; underlying(i) = elem ; p }
  }
  
  case class MutableBufferWrapper[A](underlying : mutable.Buffer[A]) extends ju.AbstractList[A] with IterableWrapperTrait[A] {
    def get(i : Int) = underlying(i)
    override def set(i : Int, elem: A) = { val p = underlying(i) ; underlying(i) = elem ; p }
    override def add(elem : A) = { underlying.append(elem) ; true }
    override def remove(i : Int) = underlying.remove(i)
  }
  
  case class JListWrapper[A](val underlying : ju.List[A]) extends mutable.Buffer[A] {
    def length = underlying.size
    override def isEmpty = underlying.isEmpty
    override def iterator : Iterator[A] = underlying.iterator
    def apply(i : Int) = underlying.get(i)
    def update(i : Int, elem : A) = underlying.set(i, elem)
    def +=:(elem : A) = { underlying.subList(0, 0).add(elem) ; this } 
    def +=(elem : A): this.type = { underlying.add(elem); this }
    def insertAll(i : Int, elems : Traversable[A]) = { val ins = underlying.subList(0, i) ;  elems.seq.foreach(ins.add(_)) }
    def remove(i : Int) = underlying.remove(i)
    def clear = underlying.clear
    def result = this
  }
  
  class SetWrapper[A](underlying: Set[A]) extends ju.AbstractSet[A] {
    self =>
    def size = underlying.size
    def iterator = new ju.Iterator[A] {
      val ui = underlying.iterator
      var prev : Option[A] = None
      def hasNext = ui.hasNext
      def next = { val e = ui.next ; prev = Some(e) ; e }
      def remove = prev match {
        case Some(e) => 
          underlying match {
            case ms: mutable.Set[a] => 
              ms.remove(e.asInstanceOf[a])
              prev = None
            case _ =>
              throw new UnsupportedOperationException("remove")
          }
        case _ => throw new IllegalStateException("next must be called at least once before remove")
      }
    }
  }

  case class MutableSetWrapper[A](underlying : mutable.Set[A]) extends SetWrapper[A](underlying) {
    override def add(elem: A) = { val sz = underlying.size ; underlying += elem ; sz < underlying.size }
    override def remove(elem : AnyRef) = try {
      underlying.remove(elem.asInstanceOf[A])
    } catch {
      case ex: ClassCastException => false
    }
    override def clear() = underlying.clear()
  }
  
  case class JSetWrapper[A](underlying : ju.Set[A]) extends mutable.Set[A] with mutable.SetLike[A, JSetWrapper[A]] {
    override def size = underlying.size

    def iterator = underlying.iterator
  
    def contains(elem: A): Boolean = underlying.contains(elem)
  
    def +=(elem: A): this.type = { underlying.add(elem); this }
    def -=(elem: A): this.type = { underlying.remove(elem); this }

    override def add(elem: A): Boolean = underlying.add(elem)
    override def remove(elem: A): Boolean = underlying.remove(elem)
    override def clear() = underlying.clear()

    override def empty = JSetWrapper(new ju.HashSet[A])
  }

  class MapWrapper[A, B](underlying: Map[A, B]) extends ju.AbstractMap[A, B] { self =>
    override def size = underlying.size

    override def get(key: AnyRef): B = try {
      underlying get key.asInstanceOf[A] match {
        case None => null.asInstanceOf[B]
        case Some(v) => v
      }
    } catch {
      case ex: ClassCastException => null.asInstanceOf[B]
    }

    override def entrySet: ju.Set[ju.Map.Entry[A, B]] = new ju.AbstractSet[ju.Map.Entry[A, B]] {
      def size = self.size

      def iterator = new ju.Iterator[ju.Map.Entry[A, B]] {
        val ui = underlying.iterator
        var prev : Option[A] = None
        
        def hasNext = ui.hasNext
      
        def next() = {
          val (k, v) = ui.next
          prev = Some(k)
          new ju.Map.Entry[A, B] {
            def getKey = k
            def getValue = v
            def setValue(v1 : B) = self.put(k, v1)
            override def hashCode = k.hashCode + v.hashCode
            override def equals(other: Any) = other match {
              case e : ju.Map.Entry[_, _] => k == e.getKey && v == e.getValue
              case _ => false
            }
          }
        }
        
        def remove() = prev match {
          case Some(k) => 
            underlying match {
              case mm: mutable.Map[a, _] =>
                val v = mm.remove(k.asInstanceOf[a])
                prev = None
                v
              case _ =>
                throw new UnsupportedOperationException("remove")
            }
          case _ => 
            throw new IllegalStateException("next must be called at least once before remove")
        }
      }
    }
  }

  case class MutableMapWrapper[A, B](underlying: mutable.Map[A, B])
  extends MapWrapper[A, B](underlying) {
    override def put(k : A, v : B) = underlying.put(k, v) match {
      case Some(v1) => v1
      case None => null.asInstanceOf[B]
    }
    
    override def remove(k : AnyRef): B = try {
      underlying.remove(k.asInstanceOf[A]) match {
        case None => null.asInstanceOf[B]
        case Some(v) => v
      }
    } catch {
      case ex: ClassCastException => null.asInstanceOf[B]
    }

    override def clear() = underlying.clear()
  }
  
  trait JMapWrapperLike[A, B, +Repr <: mutable.MapLike[A, B, Repr] with mutable.Map[A, B]]
  extends mutable.Map[A, B] with mutable.MapLike[A, B, Repr] {
    def underlying: ju.Map[A, B]
    
    override def size = underlying.size
    
    def get(k : A) = {
      val v = underlying.get(k)
      if (v != null)
        Some(v)
      else if(underlying.containsKey(k))
        Some(null.asInstanceOf[B])
      else
        None
    }

    def +=(kv: (A, B)): this.type = { underlying.put(kv._1, kv._2); this }
    def -=(key: A): this.type = { underlying.remove(key); this }

    override def put(k : A, v : B): Option[B] = {
      val r = underlying.put(k, v)
      if (r != null) Some(r) else None
    }
    
    override def update(k : A, v : B) { underlying.put(k, v) }
    
    override def remove(k : A): Option[B] = { 
      val r = underlying.remove(k)
      if (r != null) Some(r) else None
    }

    def iterator = new Iterator[(A, B)] {
      val ui = underlying.entrySet.iterator
      def hasNext = ui.hasNext
      def next() = { val e = ui.next ; (e.getKey, e.getValue) }
    }
    
    override def clear() = underlying.clear()
    
    override def empty: Repr = null.asInstanceOf[Repr]
  }
  
  case class JMapWrapper[A, B](val underlying : ju.Map[A, B])
  extends JMapWrapperLike[A, B, JMapWrapper[A, B]] {
    override def empty = JMapWrapper(new ju.HashMap[A, B])
  }
  
  class ConcurrentMapWrapper[A, B](override val underlying: mutable.ConcurrentMap[A, B])
  extends MutableMapWrapper[A, B](underlying) with juc.ConcurrentMap[A, B] {
    
    def putIfAbsent(k: A, v: B) = underlying.putIfAbsent(k, v) match {
      case Some(v) => v
      case None => null.asInstanceOf[B]
    }
    
    def remove(k: AnyRef, v: AnyRef) = try {
      underlying.remove(k.asInstanceOf[A], v.asInstanceOf[B])
    } catch {
      case ex: ClassCastException =>
        false
    }
    
    def replace(k: A, v: B): B = underlying.replace(k, v) match {
      case Some(v) => v
      case None => null.asInstanceOf[B]
    }
    
    def replace(k: A, oldval: B, newval: B) = underlying.replace(k, oldval, newval)
  }
  
  case class JConcurrentMapWrapper[A, B](val underlying: juc.ConcurrentMap[A, B])
  extends JMapWrapperLike[A, B, JConcurrentMapWrapper[A, B]] with mutable.ConcurrentMap[A, B] {
    override def get(k: A) = {
      val v = underlying.get(k)
      if (v != null) Some(v)
      else None
    }
    
    override def empty = new JConcurrentMapWrapper(new juc.ConcurrentHashMap[A, B])
    
    def putIfAbsent(k: A, v: B): Option[B] = {
      val r = underlying.putIfAbsent(k, v)
      if (r != null) Some(r) else None
    }
    
    def remove(k: A, v: B): Boolean = underlying.remove(k, v)
    
    def replace(k: A, v: B): Option[B] = {
      val prev = underlying.replace(k, v)
      if (prev != null) Some(prev) else None
    }
    
    def replace(k: A, oldvalue: B, newvalue: B): Boolean = underlying.replace(k, oldvalue, newvalue)
  }
  
  case class DictionaryWrapper[A, B](underlying: mutable.Map[A, B])
  extends ju.Dictionary[A, B] {
    def size: Int = underlying.size
    def isEmpty: Boolean = underlying.isEmpty
    def keys: ju.Enumeration[A] = asJavaEnumeration(underlying.keysIterator)
    def elements: ju.Enumeration[B] = asJavaEnumeration(underlying.valuesIterator)
    def get(key: AnyRef) = try {
      underlying.get(key.asInstanceOf[A]) match {
        case None => null.asInstanceOf[B]
        case Some(v) => v
      }
    } catch {
      case ex: ClassCastException => null.asInstanceOf[B]
    }
    def put(key: A, value: B): B = underlying.put(key, value) match {
      case Some(v) => v
      case None => null.asInstanceOf[B]
    }
    override def remove(key: AnyRef) = try {
      underlying.remove(key.asInstanceOf[A]) match {
        case None => null.asInstanceOf[B]
        case Some(v) => v
      }
    } catch {
      case ex: ClassCastException => null.asInstanceOf[B]
    }
  }

  case class JDictionaryWrapper[A, B](underlying: ju.Dictionary[A, B])
  extends mutable.Map[A, B] {

    override def size: Int = underlying.size

    def get(k : A) = {
      val v = underlying.get(k)
      if (v != null) Some(v) else None
    }

    def +=(kv: (A, B)): this.type = { underlying.put(kv._1, kv._2); this }
    def -=(key: A): this.type = { underlying.remove(key); this }

    override def put(k : A, v : B): Option[B] = {
      val r = underlying.put(k, v)
      if (r != null) Some(r) else None
    }
    
    override def update(k : A, v : B) { underlying.put(k, v) }
    
    override def remove(k : A): Option[B] = { 
      val r = underlying.remove(k)
      if (r != null) Some(r) else None
    }

    def iterator = enumerationAsScalaIterator(underlying.keys) map (k => (k, underlying get k))
    
    override def clear() = underlying.clear()
  }

  case class JPropertiesWrapper(underlying: ju.Properties)
  extends mutable.Map[String, String] with mutable.MapLike[String, String, JPropertiesWrapper] {
    override def size = underlying.size
    
    def get(k : String) = {
      val v = underlying.get(k)
      if (v != null)
        Some(v.asInstanceOf[String])
      else
        None
    }

    def +=(kv: (String, String)): this.type = { underlying.put(kv._1, kv._2); this }
    def -=(key: String): this.type = { underlying.remove(key); this }

    override def put(k : String, v : String): Option[String] = {
      val r = underlying.put(k, v)
      if (r != null) Some(r.asInstanceOf[String]) else None
    }
    
    override def update(k : String, v : String) { underlying.put(k, v) }
    
    override def remove(k : String): Option[String] = { 
      val r = underlying.remove(k)
      if (r != null) Some(r.asInstanceOf[String]) else None
    }

    def iterator = new Iterator[(String, String)] {
      val ui = underlying.entrySet.iterator
      def hasNext = ui.hasNext
      def next() = { val e = ui.next ; (e.getKey.asInstanceOf[String], e.getValue.asInstanceOf[String]) }
    }
    
    override def clear() = underlying.clear()
    
    override def empty = JPropertiesWrapper(new ju.Properties)
    
    def getProperty(key: String) = underlying.getProperty(key)
    
    def getProperty(key: String, defaultValue: String) = underlying.getProperty(key, defaultValue)
    
    def setProperty(key: String, value: String) = underlying.setProperty(key, value)
  }
}