Module io.helidon.common.reactive

Package io.helidon.common.reactive

Interface Multi<T>

Type Parameters:

T - item type

All Superinterfaces:

Flow.Publisher<T>, Subscribable<T>

All Known Implementing Classes:

ConcatPublisher, MultiCoupledProcessor, MultiDistinctProcessor, MultiDropWhileProcessor, MultiFilterProcessor, MultiFlatMapProcessor, MultiLimitProcessor, MultiMapProcessor, MultiOnErrorResumeProcessor, MultiPeekProcessor, MultiSkipProcessor, MultiTakeWhileProcessor, MultiTappedProcessor

public interface Multi<T>
extends Subscribable<T>

Multiple items publisher facility.

Method Summary

Modifier and Type	Method	Description
default <U> Single<U>	collect(Collector<T,U> collector)	Collect the items of this Multi instance into a Single.
default Single<List<T>>	collectList()	Collect the items of this Multi instance into a Single of List.
static <T> Multi<T>	concat(Multi<T> firstMulti, Multi<T> secondMulti)	Concat streams to one.
default Multi<T>	distinct()	Filter out all duplicates.
default Multi<T>	dropWhile(Predicate<T> predicate)	Drop the longest prefix of elements from this stream that satisfy the given predicate.
static <T> Multi<T>	empty()	Get a Multi instance that completes immediately.
static <T> Multi<T>	error(Throwable error)	Create a Multi instance that reports the given exception to its subscriber(s).
default Multi<T>	filter(Predicate<T> predicate)	Filter stream items with provided predicate.
default Single<T>	first()	Get the first item of this Multi instance as a Single.
default Multi<T>	flatMap(Function<T,Flow.Publisher<T>> publisherMapper)	Transform item with supplied function and flatten resulting Flow.Publisher to downstream.
default Multi<T>	flatMapIterable(Function<T,Iterable<T>> iterableMapper)	Transform item with supplied function and flatten resulting Iterable to downstream.
default void	forEach(Consumer<T> consumer)	Terminal stage, invokes provided consumer for every item in the stream.
static <T> Multi<T>	from(Iterable<T> iterable)	Create a Multi instance that publishes the given iterable.
static <T> Multi<T>	from(Flow.Publisher<T> source)	Create a Multi instance wrapped around the given publisher.
static <T> Multi<T>	just(Collection<T> items)	Create a Multi instance that publishes the given items to a single subscriber.
static <T> Multi<T>	just(T... items)	Create a Multi instance that publishes the given items to a single subscriber.
default Multi<T>	limit(long limit)	Limit stream to allow only specified number of items to pass.
default <U> Multi<U>	map(Mapper<T,U> mapper)	Map this Multi instance to a new Multi of another type using the given Mapper.
static <T> Multi<T>	never()	Get a Multi instance that never completes.
default Multi<T>	peek(Consumer<T> consumer)	Invoke provided consumer for every item in stream.
default Multi<T>	skip(long skip)	Skip first n items, all the others are emitted.
default Multi<T>	takeWhile(Predicate<T> predicate)	Take the longest prefix of elements from this stream that satisfy the given predicate.

Methods inherited from interface java.util.concurrent.Flow.Publisher

subscribe

Methods inherited from interface io.helidon.common.reactive.Subscribable

onComplete, onError, onErrorResume, onErrorResumeWith, onTerminate, subscribe, subscribe, subscribe, subscribe

Method Detail

map

default <U> Multi<U> map(Mapper<T,U> mapper)

Map this Multi instance to a new Multi of another type using the given Mapper.

Type Parameters:

U - mapped item type

Parameters:

mapper - mapper

Returns:

Multi

Throws:

NullPointerException - if mapper is null

peek

default Multi<T> peek(Consumer<T> consumer)

Invoke provided consumer for every item in stream.

Parameters:

consumer - consumer to be invoked

Returns:

Multi

distinct

default Multi<T> distinct()

Filter out all duplicates.

Returns:

Multi

filter

default Multi<T> filter(Predicate<T> predicate)

Filter stream items with provided predicate.

Parameters:

predicate - predicate to filter stream with

Returns:

Multi

takeWhile

default Multi<T> takeWhile(Predicate<T> predicate)

Take the longest prefix of elements from this stream that satisfy the given predicate. As long as predicate returns true, items from upstream are sent to downstream, when predicate returns false stream is completed.

Parameters:

predicate - predicate to filter stream with

Returns:

Multi

dropWhile

default Multi<T> dropWhile(Predicate<T> predicate)

Drop the longest prefix of elements from this stream that satisfy the given predicate. As long as predicate returns true, items from upstream are NOT sent to downstream but being dropped, predicate is never called again after it returns false for the first time.

Parameters:

predicate - predicate to filter stream with

Returns:

Multi

limit

default Multi<T> limit(long limit)

Limit stream to allow only specified number of items to pass.

Parameters:

limit - with expected number of items to be produced

Returns:

Multi

skip

default Multi<T> skip(long skip)

Skip first n items, all the others are emitted.

Parameters:

skip - number of items to be skipped

Returns:

Multi

flatMap

default Multi<T> flatMap(Function<T,Flow.Publisher<T>> publisherMapper)

Transform item with supplied function and flatten resulting Flow.Publisher to downstream.

Parameters:

publisherMapper - Function receiving item as parameter and returning Flow.Publisher

Returns:

Multi

flatMapIterable

default Multi<T> flatMapIterable(Function<T,Iterable<T>> iterableMapper)

Transform item with supplied function and flatten resulting Iterable to downstream.

Parameters:

iterableMapper - Function receiving item as parameter and returning Iterable

Returns:

Multi

forEach

default void forEach(Consumer<T> consumer)

Terminal stage, invokes provided consumer for every item in the stream.

Parameters:

consumer - consumer to be invoked for each item

collectList

default Single<List<T>> collectList()

Collect the items of this Multi instance into a Single of List.

Returns:

Single

collect

default <U> Single<U> collect(Collector<T,U> collector)

Collect the items of this Multi instance into a Single.

Type Parameters:

U - collector container type

Parameters:

collector - collector to use

Returns:

Single

Throws:

NullPointerException - if collector is null

first

default Single<T> first()

Get the first item of this Multi instance as a Single.

Returns:

Single

from

static <T> Multi<T> from(Flow.Publisher<T> source)

Create a Multi instance wrapped around the given publisher.

Type Parameters:

T - item type

Parameters:

source - source publisher

Returns:

Multi

Throws:

NullPointerException - if source is null

from

static <T> Multi<T> from(Iterable<T> iterable)

Create a Multi instance that publishes the given iterable.

Type Parameters:

T - item type

Parameters:

iterable - iterable to publish

Returns:

Multi

Throws:

NullPointerException - if iterable is null

just

static <T> Multi<T> just(Collection<T> items)

Create a Multi instance that publishes the given items to a single subscriber.

Type Parameters:

T - item type

Parameters:

items - items to publish

Returns:

Multi

Throws:

NullPointerException - if items is null

just

@SafeVarargs
static <T> Multi<T> just(T... items)

Create a Multi instance that publishes the given items to a single subscriber.

Type Parameters:

T - item type

Parameters:

items - items to publish

Returns:

Multi

Throws:

NullPointerException - if items is null

error

static <T> Multi<T> error(Throwable error)

Create a Multi instance that reports the given exception to its subscriber(s). The exception is reported by invoking Flow.Subscriber.onError(java.lang.Throwable) when Flow.Publisher.subscribe(Subscriber) is called.

Type Parameters:

T - item type

Parameters:

error - exception to hold

Returns:

Multi

Throws:

NullPointerException - if error is null

empty

static <T> Multi<T> empty()

Get a Multi instance that completes immediately.

Type Parameters:

T - item type

Returns:

Multi

never

static <T> Multi<T> never()

Get a Multi instance that never completes.

Type Parameters:

T - item type

Returns:

Multi

concat

static <T> Multi<T> concat(Multi<T> firstMulti,
                           Multi<T> secondMulti)

Concat streams to one.

Type Parameters:

T - item type

Parameters:

firstMulti - first stream

secondMulti - second stream

Returns:

Multi