Package org.springframework.data.util

Interface Streamable<T>

All Superinterfaces:

Iterable<T>, Supplier<Stream<T>>

All Known Subinterfaces:

Page<T>, PersistentPropertyPath<P>, PersistentPropertyPaths<T,P>, PropertyPath, Slice<T>, Window<T>

All Known Implementing Classes:

DefaultParameters, EntityProjection, EntityProjection.ContainerPropertyProjection, EntityProjection.PropertyProjection, ExpressionDependencies, GeoPage, PageImpl, Parameters, PartTree, PartTree.OrPart, PersistentEntities, QSort, RepositoryComposition.RepositoryFragments, Revisions, RevisionSort, SliceImpl, Sort, Sort.TypedSort

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Streamable<T>
extends Iterable<T>, Supplier<Stream<T>>

Simple interface to ease streamability of Iterables.

Since:

2.0

Author:

Oliver Gierke, Christoph Strobl

Method Summary

Modifier and Type	Method	Description
default Streamable<T>	and(Iterable<? extends T> iterable)	Creates a new Streamable from the current one and the given Iterable concatenated.
default Streamable<T>	and(Supplier<? extends Stream<? extends T>> stream)	Creates a new Streamable from the current one and the given Stream concatenated.
default Streamable<T>	and(Streamable<? extends T> streamable)	Convenience method to allow adding a Streamable directly as otherwise the invocation is ambiguous between and(Iterable) and and(Supplier).
default Streamable<T>	and(T... others)	Creates a new Streamable from the current one and the given values concatenated.
static <T> Streamable<T>	empty()	Returns an empty Streamable.
default Streamable<T>	filter(Predicate<? super T> predicate)	Returns a new Streamable that will apply the given filter Predicate to the current one.
default <R> Streamable<R>	flatMap(Function<? super T,? extends Stream<? extends R>> mapper)	Returns a new Streamable that will apply the given Function to the current one.
default Stream<T>	get()
default boolean	isEmpty()	Returns whether the current Streamable is empty.
default <R> Streamable<R>	map(Function<? super T,? extends R> mapper)	Returns a new Streamable that will apply the given Function to the current one.
static <T> Streamable<T>	of(Iterable<T> iterable)	Returns a Streamable for the given Iterable.
static <T> Streamable<T>	of(Supplier<? extends Stream<T>> supplier)
static <T> Streamable<T>	of(T... t)	Returns a Streamable with the given elements.
default Stream<T>	stream()	Creates a non-parallel Stream of the underlying Iterable.
default List<T>	toList()	Creates a new, unmodifiable List.
default Set<T>	toSet()	Creates a new, unmodifiable Set.
static <S> Collector<S,?,Streamable<S>>	toStreamable()	A collector to easily produce a Streamable from a Stream using Collectors.toList() as intermediate collector.
static <S, T extends Iterable<S>> Collector<S,?,Streamable<S>>	toStreamable(Collector<S,?,T> intermediate)	A collector to easily produce a Streamable from a Stream and the given intermediate collector.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Details

empty

static <T> Streamable<T> empty()

Returns an empty Streamable.

Returns:

will never be null.

of

@SafeVarargs
static <T> Streamable<T> of(T... t)

Returns a Streamable with the given elements.

Parameters:

t - the elements to return.

Returns:

of

static <T> Streamable<T> of(Iterable<T> iterable)

Returns a Streamable for the given Iterable.

Parameters:

iterable - must not be null.

Returns:

of

static <T> Streamable<T> of(Supplier<? extends Stream<T>> supplier)

stream

default Stream<T> stream()

Creates a non-parallel Stream of the underlying Iterable.

Returns:

will never be null.

map

default <R> Streamable<R> map(Function<? super T,? extends R> mapper)

Returns a new Streamable that will apply the given Function to the current one.

Parameters:

mapper - must not be null.

Returns:

See Also:

• Stream.map(Function)

flatMap

default <R> Streamable<R> flatMap(Function<? super T,? extends Stream<? extends R>> mapper)

Returns a new Streamable that will apply the given Function to the current one.

Parameters:

mapper - must not be null.

Returns:

See Also:

• Stream.flatMap(Function)

filter

default Streamable<T> filter(Predicate<? super T> predicate)

Returns a new Streamable that will apply the given filter Predicate to the current one.

Parameters:

predicate - must not be null.

Returns:

See Also:

• Stream.filter(Predicate)

isEmpty

default boolean isEmpty()

Returns whether the current Streamable is empty.

Returns:

and

default Streamable<T> and(Supplier<? extends Stream<? extends T>> stream)

Creates a new Streamable from the current one and the given Stream concatenated.

Parameters:

stream - must not be null.

Returns:

Since:

2.1

and

default Streamable<T> and(T... others)

Creates a new Streamable from the current one and the given values concatenated.

Parameters:

others - must not be null.

Returns:

will never be null.

Since:

2.2

and

default Streamable<T> and(Iterable<? extends T> iterable)

Creates a new Streamable from the current one and the given Iterable concatenated.

Parameters:

iterable - must not be null.

Returns:

will never be null.

Since:

2.2

and

default Streamable<T> and(Streamable<? extends T> streamable)

Convenience method to allow adding a Streamable directly as otherwise the invocation is ambiguous between and(Iterable) and and(Supplier).

Parameters:

streamable - must not be null.

Returns:

will never be null.

Since:

2.2

toList

default List<T> toList()

Creates a new, unmodifiable List.

Returns:

will never be null.

Since:

2.2

toSet

default Set<T> toSet()

Creates a new, unmodifiable Set.

Returns:

will never be null.

Since:

2.2

get

default Stream<T> get()

Specified by:

get in interface Supplier<T>

toStreamable

static <S> Collector<S,?,Streamable<S>> toStreamable()

A collector to easily produce a Streamable from a Stream using Collectors.toList() as intermediate collector.

Returns:

Since:

2.2

See Also:

• toStreamable(Collector)

toStreamable

static <S,
T extends Iterable<S>>
Collector<S,?,Streamable<S>> toStreamable(Collector<S,?,T> intermediate)

A collector to easily produce a Streamable from a Stream and the given intermediate collector.

Returns:

Since:

2.2