Package uk.gov.gchq.gaffer.commonutil.stream

Class GafferCollectors

java.lang.Object

uk.gov.gchq.gaffer.commonutil.stream.GafferCollectors

public final class GafferCollectors
extends Object

Java 8 Collectors for Gaffer, based on the Collectors class. Please note that using a Collector to gather together the items contained in a Stream will result in those items being loaded into memory.

Method Summary

Modifier and Type	Method	Description
static <T> Collector<T,LimitedInMemorySortedIterable<T>,LimitedInMemorySortedIterable<T>>	toLimitedInMemorySortedIterable(Comparator<T> comparator, Integer limit, boolean deduplicate)	Returns a Collector that accumulates the input items into a LimitedInMemorySortedIterable.
static <T> Collector<T,?,Set<T>>	toLinkedHashSet()	Returns a Collector that accumulates the input items into a LinkedHashSet.

Methods inherited from class java.lang.Object

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

Method Detail

toLinkedHashSet

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

Returns a Collector that accumulates the input items into a LinkedHashSet.

Type Parameters:

T - the type of the input items

Returns:

a Collector which collects all the input elements into a LinkedHashSet

toLimitedInMemorySortedIterable

public static <T> Collector<T,LimitedInMemorySortedIterable<T>,LimitedInMemorySortedIterable<T>> toLimitedInMemorySortedIterable(Comparator<T> comparator,
                                                                                                                                             Integer limit,
                                                                                                                                             boolean deduplicate)

Returns a Collector that accumulates the input items into a LimitedInMemorySortedIterable.

The usage of a LimitedInMemorySortedIterable ensures that only relevant results are stored in memory, as the output is built up incrementally.

Type Parameters:

T - the type of input items

Parameters:

comparator - the Comparator to use when comparing items

limit - the maximum number of items to collect

deduplicate - true if the results should be deduplicated based the items hashcode/equals methods

Returns:

a Collector which collects all the input elements into a LimitedInMemorySortedIterable