Module org.omnifaces.utils

Package org.omnifaces.utils.stream

Class Collectors

java.lang.Object

org.omnifaces.utils.stream.Collectors

public final class Collectors
extends Object

Method Summary

Modifier and Type	Method	Description
static <T,R1,R2> Collector<T,?,Map.Entry<R1,R2>>	combine(Collector<T,?,R1> collector1, Collector<T,?,R2> collector2)
static <T> Collector<T,?,Optional<T>>	findLast()	Returns a collector which will return the last element of a stream, if present.
static <T> Collector<T,?,Void>	forEachBatch(Consumer<List<T>> batchConsumer, int batchSize)
static <T> Collector<T,?,Stream<T>>	reversedStream()	Returns a collector which takes the elements of the current stream and returns a new stream with the same elements in reverse order.
static <T extends Comparable<T>> Collector<T,?,Summary<T>>	summary()
static <T> Collector<T,?,Summary<T>>	summaryBy(Comparator<? super T> comparator)
static <T,K> Collector<T,?,Map<K,T>>	toLinkedMap(Function<? super T,? extends K> keyMapper)
static <T> Collector<T,?,Set<T>>	toLinkedSet()
static <T,K> Collector<T,?,Map<K,T>>	toMap(Function<? super T,? extends K> keyMapper)

Methods inherited from class java.lang.Object

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

Method Detail

toMap

public static <T,K> Collector<T,?,Map<K,T>> toMap(Function<? super T,? extends K> keyMapper)

toLinkedMap

public static <T,K> Collector<T,?,Map<K,T>> toLinkedMap(Function<? super T,? extends K> keyMapper)

toLinkedSet

public static <T> Collector<T,?,Set<T>> toLinkedSet()

forEachBatch

public static <T> Collector<T,?,Void> forEachBatch(Consumer<List<T>> batchConsumer,
                                                               int batchSize)

combine

public static <T,R1,R2> Collector<T,?,Map.Entry<R1,R2>> combine(Collector<T,?,R1> collector1,
                                                                                              Collector<T,?,R2> collector2)

reversedStream

public static <T> Collector<T,?,Stream<T>> reversedStream()

Returns a collector which takes the elements of the current stream and returns a new stream with the same elements in reverse order.

This collector will collect all elements from a stream into memory in order to return the reversed stream. As a result this collector may not be suitable for extremely large or infinite streams.

Type Parameters:

T - The type of the elements

Returns:

A Collector that returns the elements of a stream in reverse order.

findLast

public static <T> Collector<T,?,Optional<T>> findLast()

Returns a collector which will return the last element of a stream, if present.

Type Parameters:

T - The type of the elements

Returns:

An Optional containing the last element of the stream or Optional.empty() if the stream is empty.

summary

public static <T extends Comparable<T>> Collector<T,?,Summary<T>> summary()

summaryBy

public static <T> Collector<T,?,Summary<T>> summaryBy(Comparator<? super T> comparator)