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
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	OptionConverters.RichOptionalDouble Provides conversions from `java.util.OptionalDouble` to the generic `Optional` and Scala `Option`
static class	OptionConverters.RichOptionalDouble$
static class	OptionConverters.RichOptionalGeneric<A> Provides conversions from `java.util.Optional` to Scala `Option` or primitive `java.util.Optional` types
static class	OptionConverters.RichOptionalGeneric$
static class	OptionConverters.RichOptionalInt Provides conversions from `java.util.OptionalInt` to the generic `Optional` and Scala `Option`
static class	OptionConverters.RichOptionalInt$
static class	OptionConverters.RichOptionalLong Provides conversions from `java.util.OptionalLong` to the generic `Optional` and Scala `Option`
static class	OptionConverters.RichOptionalLong$
static class	OptionConverters.RichOptionForJava8<A> Provides conversions from `scala.Option` to Java `Optional` types, either generic or primitive
static class	OptionConverters.RichOptionForJava8$
static class	OptionConverters.SpecializerOfOptions<A,That> Type class implementing conversion from generic `Option` or `Optional` to manually specialized variants.

Constructor Summary

Constructors

Constructor and Description
OptionConverters()

Method Summary

Modifier and Type	Method and Description
static OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalDouble>	specializer_OptionalDouble() Implementation of creation of `OptionalDouble` from `Option[Double]` or `Optional[Double]`
static OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalInt>	specializer_OptionalInt() Implementation of creation of `OptionalInt` from `Option[Int]` or `Optional[Int]`
static OptionConverters.SpecializerOfOptions<java.lang.Object,java.util.OptionalLong>	specializer_OptionalLong() Implementation of creation of `OptionalLong` from `Option[Long]` or `Optional[Long]`
static <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.
static <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
static 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
static 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
static 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

Constructor Detail

OptionConverters

public OptionConverters()

Method Detail

specializer_OptionalDouble

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

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

specializer_OptionalInt

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

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

specializer_OptionalLong

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

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

toJava

public static 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 static 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 static 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 static 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 static 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