play.libs

Class Scala

java.lang.Object

play.libs.Scala

public class Scala
extends java.lang.Object

Class that contains useful java <-> scala conversion helpers.

Constructor Summary

Constructors

Constructor and Description
Scala()

Method Summary

Modifier and Type	Method and Description
static <T> T[]	asArray(java.lang.Class<T> clazz, scala.collection.Seq<T> scalaList) Converts a Scala List to an Array.
static <K,V> java.util.Map<K,V>	asJava(scala.collection.Map<K,V> scalaMap) Converts a Scala Map to Java.
static <T> java.util.List<T>	asJava(scala.collection.Seq<T> scalaList) Converts a Scala List to Java.
static <A,B> F.Tuple<A,B>	asJava(scala.Tuple2<A,B> tuple) Convert a scala Tuple2 to a java F.Tuple.
static <A> scala.Function0<A>	asScala(java.util.concurrent.Callable<A> callable) Converts a Java Callable to a Scala Function0.
static <A> scala.collection.immutable.Seq<A>	asScala(java.util.Collection<A> javaCollection) Converts a Java Collection to a Scala Seq.
static <A,B> scala.collection.immutable.Map<A,B>	asScala(java.util.Map<A,B> javaMap) Converts a Java Map to Scala.
static <C> scala.reflect.ClassTag<C>	classTag() Returns an any ClassTag typed according to the Java compiler as C.
static <A,B> scala.collection.immutable.Map<A,B>	emptyMap() Creates an empty Scala Map.
static <T> scala.collection.Seq<T>	emptySeq() Creates an empty Scala Seq.
static java.lang.RuntimeException	noMatch() Throw this exception to indicate that a partial function doesn't match.
static <T> scala.Option<T>	None() None
static <T> scala.Option<T>	Option(T t) Wrap a value into a Scala Option.
static <T> T	orElse(scala.Option<T> opt, T defaultValue) Wrap a Scala Option, handling None by returning a defaultValue
static <T> T	orNull(scala.Option<T> opt) Wrap a Scala Option, handling None as null.
static <A,B> scala.PartialFunction<A,B>	partialFunction(java.util.function.Function<A,B> f) Create a Scala PartialFunction from a function.
static <T> scala.collection.Seq<T>	toSeq(java.util.List<T> list) Converts a Java List to Scala Seq.
static <T> scala.collection.Seq<T>	toSeq(T[] array) Converts a Java Array to Scala Seq.
static <A,B> scala.Tuple2<A,B>	Tuple(A a, B b) Create a Scala Tuple2.
static <T> scala.collection.Seq<T>	varargs(T... array) Converts a Java varargs to Scala Seq.

Methods inherited from class java.lang.Object

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

Constructor Detail

Scala

public Scala()

Method Detail

orNull

public static <T> T orNull(scala.Option<T> opt)

Wrap a Scala Option, handling None as null.

orElse

public static <T> T orElse(scala.Option<T> opt,
                           T defaultValue)

Wrap a Scala Option, handling None by returning a defaultValue

asJava

public static <K,V> java.util.Map<K,V> asJava(scala.collection.Map<K,V> scalaMap)

Converts a Scala Map to Java.

asScala

public static <A,B> scala.collection.immutable.Map<A,B> asScala(java.util.Map<A,B> javaMap)

Converts a Java Map to Scala.

asScala

public static <A> scala.collection.immutable.Seq<A> asScala(java.util.Collection<A> javaCollection)

Converts a Java Collection to a Scala Seq.

asScala

public static <A> scala.Function0<A> asScala(java.util.concurrent.Callable<A> callable)

Converts a Java Callable to a Scala Function0.

asJava

public static <T> java.util.List<T> asJava(scala.collection.Seq<T> scalaList)

Converts a Scala List to Java.

asArray

public static <T> T[] asArray(java.lang.Class<T> clazz,
                              scala.collection.Seq<T> scalaList)

Converts a Scala List to an Array.

toSeq

public static <T> scala.collection.Seq<T> toSeq(java.util.List<T> list)

Converts a Java List to Scala Seq.

toSeq

public static <T> scala.collection.Seq<T> toSeq(T[] array)

Converts a Java Array to Scala Seq.

varargs

public static <T> scala.collection.Seq<T> varargs(T... array)

Converts a Java varargs to Scala Seq.

Option

public static <T> scala.Option<T> Option(T t)

Wrap a value into a Scala Option.

None

public static <T> scala.Option<T> None()

None

Tuple

public static <A,B> scala.Tuple2<A,B> Tuple(A a,
                                            B b)

Create a Scala Tuple2.

asJava

public static <A,B> F.Tuple<A,B> asJava(scala.Tuple2<A,B> tuple)

Convert a scala Tuple2 to a java F.Tuple.

emptySeq

public static <T> scala.collection.Seq<T> emptySeq()

Creates an empty Scala Seq.

emptyMap

public static <A,B> scala.collection.immutable.Map<A,B> emptyMap()

Creates an empty Scala Map.

classTag

public static <C> scala.reflect.ClassTag<C> classTag()

Returns an any ClassTag typed according to the Java compiler as C.

partialFunction

public static <A,B> scala.PartialFunction<A,B> partialFunction(java.util.function.Function<A,B> f)

Create a Scala PartialFunction from a function. A PartialFunction is one that isn't defined for the whole of its domain. If the function isn't defined for a particular input parameter, it can throw F.noMatch(), and this will be translated into the semantics of a Scala PartialFunction. For example:

     Flow<String, Integer, ?> collectInts = Flow.<String>collect(Scala.partialFunction( str -> {
         try {
             return Integer.parseInt(str);
         } catch (NumberFormatException e) {
             throw Scala.noMatch();
         }
     }));
 

The above code will convert a flow of String into a flow of Integer, dropping any strings that can't be parsed as integers.

Parameters:

f - The function to make a partial function from.

Returns:

A Scala PartialFunction.

noMatch

public static java.lang.RuntimeException noMatch()

Throw this exception to indicate that a partial function doesn't match.

Returns:

An exception that indicates a partial function doesn't match.