Object scala.collection.JavaConversions

object JavaConversions extends WrapAsScala with WrapAsJava

A variety 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.concurrent.Map <=> 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:

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]

The transparent conversions provided here are considered fragile because they can result in unexpected behavior and performance.

Therefore, this API has been deprecated and JavaConverters should be used instead. JavaConverters provides the same conversions, but through extension methods.

Annotations
@deprecated
Deprecated

(Since version 2.12.0) use JavaConverters

Source
JavaConversions.scala
Since

2.8

Linear Supertypes

Value Members

final def !=(arg0: Any): Boolean

Test two objects for inequality.

returns

true if !(this == that), false otherwise.

Definition Classes
AnyRef → Any

final def ##(): Int

Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

returns

a hash value consistent with ==

Definition Classes
AnyRef → Any

final def ==(arg0: Any): Boolean

The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

returns

true if the receiver object is equivalent to the argument; false otherwise.

Definition Classes
AnyRef → Any

final def asInstanceOf[T0]: T0

Cast the receiver object to be of type T0.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

returns

the receiver object.

Definition Classes
Any
Exceptions thrown

ClassCastException if the receiver object is not an instance of the erasure of type T0.

implicit def asJavaCollection[A](it: Iterable[A]): Collection[A]

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.

it

The SizedIterable to be converted.

returns

A Java Collection view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def asJavaDictionary[A, B](m: mutable.Map[A, B]): Dictionary[A, B]

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.

m

The Map to be converted.

returns

A Java Dictionary view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def asJavaEnumeration[A](it: Iterator[A]): java.util.Enumeration[A]

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.

it

The Iterator to be converted.

returns

A Java Enumeration view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def asJavaIterable[A](i: Iterable[A]): java.lang.Iterable[A]

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.

i

The Iterable to be converted.

returns

A Java Iterable view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def asJavaIterator[A](it: Iterator[A]): java.util.Iterator[A]

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.

it

The Iterator to be converted.

returns

A Java Iterator view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def asScalaBuffer[A](l: java.util.List[A]): Buffer[A]

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.

l

The List to be converted.

returns

A Scala mutable Buffer view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def asScalaIterator[A](it: java.util.Iterator[A]): Iterator[A]

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.

it

The Iterator to be converted.

returns

A Scala Iterator view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def asScalaSet[A](s: java.util.Set[A]): mutable.Set[A]

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.

s

The Set to be converted.

returns

A Scala mutable Set view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def bufferAsJavaList[A](b: Buffer[A]): java.util.List[A]

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.

b

The Buffer to be converted.

returns

A Java List view of the argument.

Definition Classes
LowPriorityWrapAsJava

def clone(): AnyRef

Create a copy of the receiver object.

The default implementation of the clone method is platform dependent.

returns

a copy of the receiver object.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( ... ) @native()
Note

not specified by SLS as a member of AnyRef

implicit def collectionAsScalaIterable[A](i: Collection[A]): Iterable[A]

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.

i

The Collection to be converted.

returns

A Scala Iterable view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def deprecated asJavaCollection[A](it: Iterable[A]): Collection[A]

Definition Classes
WrapAsJava

implicit def deprecated asJavaDictionary[A, B](m: mutable.Map[A, B]): Dictionary[A, B]

Definition Classes
WrapAsJava

implicit def deprecated asJavaEnumeration[A](it: Iterator[A]): java.util.Enumeration[A]

Definition Classes
WrapAsJava

implicit def deprecated asJavaIterable[A](i: Iterable[A]): java.lang.Iterable[A]

Definition Classes
WrapAsJava

implicit def deprecated asJavaIterator[A](it: Iterator[A]): java.util.Iterator[A]

Definition Classes
WrapAsJava

implicit def deprecated asScalaBuffer[A](l: java.util.List[A]): Buffer[A]

Definition Classes
WrapAsScala

implicit def deprecated asScalaIterator[A](it: java.util.Iterator[A]): Iterator[A]

Definition Classes
WrapAsScala

implicit def deprecated asScalaSet[A](s: java.util.Set[A]): mutable.Set[A]

Definition Classes
WrapAsScala

implicit def deprecated bufferAsJavaList[A](b: Buffer[A]): java.util.List[A]

Definition Classes
WrapAsJava

implicit def deprecated collectionAsScalaIterable[A](i: Collection[A]): Iterable[A]

Definition Classes
WrapAsScala

implicit def deprecated dictionaryAsScalaMap[A, B](p: Dictionary[A, B]): mutable.Map[A, B]

Definition Classes
WrapAsScala

implicit def deprecated enumerationAsScalaIterator[A](i: java.util.Enumeration[A]): Iterator[A]

Definition Classes
WrapAsScala

implicit def deprecated iterableAsScalaIterable[A](i: java.lang.Iterable[A]): Iterable[A]

Definition Classes
WrapAsScala

implicit def deprecated mapAsJavaConcurrentMap[A, B](m: concurrent.Map[A, B]): ConcurrentMap[A, B]

Definition Classes
WrapAsJava

implicit def deprecated mapAsJavaMap[A, B](m: Map[A, B]): java.util.Map[A, B]

Definition Classes
WrapAsJava

implicit def deprecated mapAsScalaConcurrentMap[A, B](m: ConcurrentMap[A, B]): concurrent.Map[A, B]

Definition Classes
WrapAsScala

implicit def deprecated mapAsScalaMap[A, B](m: java.util.Map[A, B]): mutable.Map[A, B]

Definition Classes
WrapAsScala

implicit def deprecated mutableMapAsJavaMap[A, B](m: mutable.Map[A, B]): java.util.Map[A, B]

Definition Classes
WrapAsJava

implicit def deprecated mutableSeqAsJavaList[A](seq: mutable.Seq[A]): java.util.List[A]

Definition Classes
WrapAsJava

implicit def deprecated mutableSetAsJavaSet[A](s: mutable.Set[A]): java.util.Set[A]

Definition Classes
WrapAsJava

implicit def deprecated propertiesAsScalaMap(p: Properties): mutable.Map[String, String]

Definition Classes
WrapAsScala

implicit def deprecated seqAsJavaList[A](seq: Seq[A]): java.util.List[A]

Definition Classes
WrapAsJava

implicit def deprecated setAsJavaSet[A](s: Set[A]): java.util.Set[A]

Definition Classes
WrapAsJava

implicit def dictionaryAsScalaMap[A, B](p: Dictionary[A, B]): mutable.Map[A, B]

Implicitly converts a Java Dictionary to a Scala mutable Map.

The returned Scala Map 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.

p

The Dictionary to be converted.

returns

A Scala mutable Map view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def enumerationAsScalaIterator[A](i: java.util.Enumeration[A]): Iterator[A]

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.

i

The Enumeration to be converted.

returns

A Scala Iterator view of the argument.

Definition Classes
LowPriorityWrapAsScala

final def eq(arg0: AnyRef): Boolean

Tests whether the argument (that) is a reference to the receiver object (this).

The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. null.eq(null) returns true.

When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

returns

true if the argument is a reference to the receiver object; false otherwise.

Definition Classes
AnyRef

def equals(arg0: Any): Boolean

The equality method for reference types. Default implementation delegates to eq.

See also equals in scala.Any.

returns

true if the receiver object is equivalent to the argument; false otherwise.

Definition Classes
AnyRef → Any

def finalize(): Unit

Called by the garbage collector on the receiver object when there are no more references to the object.

The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
Note

not specified by SLS as a member of AnyRef

final def getClass(): Class[_]

Returns the runtime class representation of the object.

returns

a class object corresponding to the runtime type of the receiver.

Definition Classes
AnyRef → Any
Annotations
@native()

def hashCode(): Int

The hashCode method for reference types. See hashCode in scala.Any.

returns

the hash code value for this object.

Definition Classes
AnyRef → Any
Annotations
@native()

final def isInstanceOf[T0]: Boolean

Test whether the dynamic type of the receiver object is T0.

Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

returns

true if the receiver object is an instance of erasure of type T0; false otherwise.

Definition Classes
Any

implicit def iterableAsScalaIterable[A](i: java.lang.Iterable[A]): Iterable[A]

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.

i

The Iterable to be converted.

returns

A Scala Iterable view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def mapAsJavaConcurrentMap[A, B](m: concurrent.Map[A, B]): ConcurrentMap[A, B]

Implicitly converts a Scala mutable concurrent.Map to a Java ConcurrentMap.

The returned Java ConcurrentMap is backed by the provided Scala concurrent.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 concurrent.Map was previously obtained from an implicit or explicit call of mapAsScalaConcurrentMap(java.util.concurrent.ConcurrentMap) then the original Java ConcurrentMap will be returned.

m

The Scala concurrent.Map to be converted.

returns

A Java ConcurrentMap view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def mapAsJavaMap[A, B](m: Map[A, B]): java.util.Map[A, B]

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.

m

The Map to be converted.

returns

A Java Map view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def mapAsScalaConcurrentMap[A, B](m: ConcurrentMap[A, B]): concurrent.Map[A, B]

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.

m

The ConcurrentMap to be converted.

returns

A Scala mutable ConcurrentMap view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def mapAsScalaMap[A, B](m: java.util.Map[A, B]): mutable.Map[A, B]

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.

If the wrapped map is synchronized (e.g. from java.util.Collections.synchronizedMap), it is your responsibility to wrap all non-atomic operations with underlying.synchronized. This includes get, as java.util.Map's API does not allow for an atomic get when null values may be present.

m

The Map to be converted.

returns

A Scala mutable Map view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def mutableMapAsJavaMap[A, B](m: mutable.Map[A, B]): java.util.Map[A, B]

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.

m

The Map to be converted.

returns

A Java Map view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def mutableSeqAsJavaList[A](seq: mutable.Seq[A]): java.util.List[A]

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.

seq

The Seq to be converted.

returns

A Java List view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def mutableSetAsJavaSet[A](s: mutable.Set[A]): java.util.Set[A]

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.

s

The Set to be converted.

returns

A Java Set view of the argument.

Definition Classes
LowPriorityWrapAsJava

final def ne(arg0: AnyRef): Boolean

Equivalent to !(this eq that).

returns

true if the argument is not a reference to the receiver object; false otherwise.

Definition Classes
AnyRef

final def notify(): Unit

Wakes up a single thread that is waiting on the receiver object's monitor.

Definition Classes
AnyRef
Annotations
@native()
Note

not specified by SLS as a member of AnyRef

final def notifyAll(): Unit

Wakes up all threads that are waiting on the receiver object's monitor.

Definition Classes
AnyRef
Annotations
@native()
Note

not specified by SLS as a member of AnyRef

implicit def propertiesAsScalaMap(p: Properties): mutable.Map[String, String]

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.

p

The Properties to be converted.

returns

A Scala mutable Map[String, String] view of the argument.

Definition Classes
LowPriorityWrapAsScala

implicit def seqAsJavaList[A](seq: Seq[A]): java.util.List[A]

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.

seq

The Seq to be converted.

returns

A Java List view of the argument.

Definition Classes
LowPriorityWrapAsJava

implicit def setAsJavaSet[A](s: Set[A]): java.util.Set[A]

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.

s

The Set to be converted.

returns

A Java Set view of the argument.

Definition Classes
LowPriorityWrapAsJava

final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef

def toString(): String

Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

returns

a String representation of the object.

Definition Classes
AnyRef → Any

final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... ) @native()

© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/collection/JavaConversions$.html