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Scala 3/scala/scala.jdk/CollectionConverters

CollectionConverters

scala.jdk.CollectionConverters
object CollectionConverters extends AsJavaExtensions, AsScalaExtensions

This object provides extension methods that convert between Scala and Java collections.

When writing Java code, use the explicit conversion methods defined in javaapi.CollectionConverters instead.

Note: to create Java Streams that operate on Scala collections (sequentially or in parallel), use StreamConverters.

import scala.jdk.CollectionConverters._
val s: java.util.Set[String] = Set("one", "two").asJava

The conversions return adapters for the corresponding API, i.e., the collections are wrapped, not converted. Changes to the original collection are reflected in the view, and vice versa:

scala> import scala.jdk.CollectionConverters._

scala> val s = collection.mutable.Set("one")
s: scala.collection.mutable.Set[String] = HashSet(one)

scala> val js = s.asJava
js: java.util.Set[String] = [one]

scala> js.add("two")

scala> s
res2: scala.collection.mutable.Set[String] = HashSet(two, one)

The following conversions are supported via asScala and asJava:

scala.collection.Iterable       <=> java.lang.Iterable
scala.collection.Iterator       <=> java.util.Iterator
scala.collection.mutable.Buffer <=> java.util.List
scala.collection.mutable.Set    <=> java.util.Set
scala.collection.mutable.Map    <=> java.util.Map
scala.collection.concurrent.Map <=> java.util.concurrent.ConcurrentMap

The following conversions are supported via asScala and through specially-named extension methods to convert to Java collections, as shown:

scala.collection.Iterable    <=> java.util.Collection   (via asJavaCollection)
scala.collection.Iterator    <=> java.util.Enumeration  (via asJavaEnumeration)
scala.collection.mutable.Map <=> java.util.Dictionary   (via asJavaDictionary)

In addition, the following one-way conversions are provided via asJava:

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

The following one way conversion is provided via asScala:

java.util.Properties => scala.collection.mutable.Map

In all cases, converting from a source type to a target type and back again will return the original source object. For example:

import scala.jdk.CollectionConverters._

val source = new scala.collection.mutable.ListBuffer[Int]
val target: java.util.List[Int] = source.asJava
val other: scala.collection.mutable.Buffer[Int] = target.asScala
assert(source eq other)

Attributes

Source
CollectionConverters.scala
Graph
Supertypes
class Object
trait Matchable
class Any
Self type

Members list

Type members

Inherited classlikes

implicit class BufferHasAsJava[A](b: Buffer[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class CollectionHasAsScala[A](c: Collection[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class ConcurrentMapHasAsJava[K, V](m: Map[K, V])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class ConcurrentMapHasAsScala[K, V](m: ConcurrentMap[K, V])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class DictionaryHasAsScala[K, V](d: Dictionary[K, V])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class EnumerationHasAsScala[A](e: Enumeration[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class IterableHasAsJava[A](i: Iterable[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class IterableHasAsScala[A](i: Iterable[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class IteratorHasAsJava[A](i: Iterator[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class IteratorHasAsScala[A](i: Iterator[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class ListHasAsScala[A](l: List[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class MapHasAsJava[K, V](m: Map[K, V])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class MapHasAsScala[K, V](m: Map[K, V])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class MutableMapHasAsJava[K, V](m: Map[K, V])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class MutableSeqHasAsJava[A](s: Seq[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class MutableSetHasAsJava[A](s: Set[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class PropertiesHasAsScala(i: Properties)

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class SeqHasAsJava[A](s: Seq[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class SetHasAsJava[A](s: Set[A])

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
Supertypes
class Object
trait Matchable
class Any
implicit class SetHasAsScala[A](s: Set[A])

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
Supertypes
class Object
trait Matchable
class Any

Implicits

Inherited implicits

final implicit def BufferHasAsJava[A](b: Buffer[A]): BufferHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def CollectionHasAsScala[A](c: Collection[A]): CollectionHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def ConcurrentMapHasAsJava[K, V](m: Map[K, V]): ConcurrentMapHasAsJava[K, V]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def ConcurrentMapHasAsScala[K, V](m: ConcurrentMap[K, V]): ConcurrentMapHasAsScala[K, V]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def DictionaryHasAsScala[K, V](d: Dictionary[K, V]): DictionaryHasAsScala[K, V]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def EnumerationHasAsScala[A](e: Enumeration[A]): EnumerationHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def IterableHasAsJava[A](i: Iterable[A]): IterableHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def IterableHasAsScala[A](i: Iterable[A]): IterableHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def IteratorHasAsJava[A](i: Iterator[A]): IteratorHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def IteratorHasAsScala[A](i: Iterator[A]): IteratorHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def ListHasAsScala[A](l: List[A]): ListHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def MapHasAsJava[K, V](m: Map[K, V]): MapHasAsJava[K, V]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def MapHasAsScala[K, V](m: Map[K, V]): MapHasAsScala[K, V]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def MutableMapHasAsJava[K, V](m: Map[K, V]): MutableMapHasAsJava[K, V]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def MutableSeqHasAsJava[A](s: Seq[A]): MutableSeqHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def MutableSetHasAsJava[A](s: Set[A]): MutableSetHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def PropertiesHasAsScala(i: Properties): PropertiesHasAsScala

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
final implicit def SeqHasAsJava[A](s: Seq[A]): SeqHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def SetHasAsJava[A](s: Set[A]): SetHasAsJava[A]

Attributes

Inherited from:
AsJavaExtensions
Source
AsJavaExtensions.scala
final implicit def SetHasAsScala[A](s: Set[A]): SetHasAsScala[A]

Attributes

Inherited from:
AsScalaExtensions
Source
AsScalaExtensions.scala
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Copyright (c) 2002-2024, LAMP/EPFL
Copyright (c) 2002-2024, LAMP/EPFL