scala.compat.java8

Class OptionConverters$

java.lang.Object

scala.compat.java8.OptionConverters$

public class OptionConverters$
extends java.lang.Object

This class enables bidirectional conversion between scala.Option and the set of java.util.Optional classes.

The Scala Option is generic; its generic counterpart in Java is java.util.Optional. Option is enriched with an asJava method, while Optional is enriched with asScala to perform conversions.

In addition, both Option and Optional are enriched with asPrimitive methods that will convert generically contained primitives to the manually specialized Java versions for primitives, OptionalDouble, OptionalInt, and OptionalLong. The primitive versions can be converted to the Scala generic Option with asScala and to the Java generic Optional with asGeneric.

When calling from Java, methods are more convenient than extension methods, so toJava and toScala methods are provided that convert to and from Scala's Option. Note that toJava(toScala(x)) will result in a generic Optional even if x was one of the primitive versons.

Example usage:

 import scala.compat.java8.OptionConverters._
 val a = Option("example").asJava      // Creates java.util.Optional[String] containing "example"
 val b = (None: Option[String]).asJava // Creates an empty java.util.Optional[String]
 val c = a.asScala                     // Back to Option("example")
 val d = b.asScala                     // Back to None typed as Option[String]
 val e = Option(2.7).asJava            // java.util.Optional[Double] containing boxed 2.7
 val f = Option(2.7).asPrimitive       // java.util.OptionalDouble containing 2.7 (not boxed)
 val g = f.asScala                     // Back to Option(2.7)
 val h = f.asGeneric                   // Same as e
 val i = e.asPrimitive                 // Same as f
 val j = toJava(Option("example"))     // Same as a
 val k = toScala(a)                    // Same as c
 

Field Summary

Fields

Modifier and Type	Field and Description
static OptionConverters$	MODULE$ Static reference to the singleton instance of this Scala object.

Constructor Summary

Constructors

Constructor and Description
OptionConverters$()

Method Summary

Modifier and Type	Method and Description
OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalDouble>	specializer_OptionalDouble() Implementation of creation of `OptionalDouble` from `Option[Double]` or `Optional[Double]`
OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalInt>	specializer_OptionalInt() Implementation of creation of `OptionalInt` from `Option[Int]` or `Optional[Int]`
OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalLong>	specializer_OptionalLong() Implementation of creation of `OptionalLong` from `Option[Long]` or `Optional[Long]`
<A> java.util.Optional<A>	toJava(scala.Option<A> o) Conversion from Scala `Option` to Java `Optional` without using implicits, for convenient use from Java.
<A> scala.Option<A>	toScala(java.util.Optional<A> o) Conversion from Java `Optional` to Scala `Option` without using implicits, for convenient use from Java
scala.Option<java.lang.Object>	toScala(java.util.OptionalDouble o) Conversion from Java `OptionalDouble` to Scala `Option` without using implicits, for convenient use from Java
scala.Option<java.lang.Object>	toScala(java.util.OptionalInt o) Conversion from Java `OptionalInt` to Scala `Option` without using implicits, for convenient use from Java
scala.Option<java.lang.Object>	toScala(java.util.OptionalLong o) Conversion from Java `OptionalLong` to Scala `Option` without using implicits, for convenient use from Java

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MODULE$

public static final OptionConverters$ MODULE$

Static reference to the singleton instance of this Scala object.

Constructor Detail

OptionConverters$

public OptionConverters$()

Method Detail

specializer_OptionalDouble

public OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalDouble> specializer_OptionalDouble()

Implementation of creation of `OptionalDouble` from `Option[Double]` or `Optional[Double]`

specializer_OptionalInt

public OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalInt> specializer_OptionalInt()

Implementation of creation of `OptionalInt` from `Option[Int]` or `Optional[Int]`

specializer_OptionalLong

public OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalLong> specializer_OptionalLong()

Implementation of creation of `OptionalLong` from `Option[Long]` or `Optional[Long]`

toJava

public final <A> java.util.Optional<A> toJava(scala.Option<A> o)

Conversion from Scala `Option` to Java `Optional` without using implicits, for convenient use from Java.

toScala

public final <A> scala.Option<A> toScala(java.util.Optional<A> o)

Conversion from Java `Optional` to Scala `Option` without using implicits, for convenient use from Java

toScala

public final scala.Option<java.lang.Object> toScala(java.util.OptionalDouble o)

Conversion from Java `OptionalDouble` to Scala `Option` without using implicits, for convenient use from Java

toScala

public final scala.Option<java.lang.Object> toScala(java.util.OptionalInt o)

Conversion from Java `OptionalInt` to Scala `Option` without using implicits, for convenient use from Java

toScala

public final scala.Option<java.lang.Object> toScala(java.util.OptionalLong o)

Conversion from Java `OptionalLong` to Scala `Option` without using implicits, for convenient use from Java