org.danilopianini.util.stream

Class SmallestN<T>

java.lang.Object

org.danilopianini.util.stream.SmallestN<T>

Type Parameters:

T -

All Implemented Interfaces:

Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

public class SmallestN<T>
extends Object
implements Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

A fast Collector that returns the desired number of the smallest elements of a Stream into a Guava's MinMaxPriorityQueue.

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.stream.Collector

Collector.Characteristics

Field Summary

Fields

Modifier and Type	Field and Description
private static Set<Collector.Characteristics>	CHARACT
private Comparator<T>	comparator
private int	max

Constructor Summary

Constructors

Constructor and Description
SmallestN(int maxElements) No comparator supplied: natural ordering is used.
SmallestN(int maxElements, Comparator<T> comparator)

Method Summary

Modifier and Type	Method and Description
BiConsumer<MinMaxPriorityQueue<T>,T>	accumulator()
Set<Collector.Characteristics>	characteristics()
BinaryOperator<MinMaxPriorityQueue<T>>	combiner()
Function<MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>	finisher()
Supplier<MinMaxPriorityQueue<T>>	supplier()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.stream.Collector

of, of

Field Detail

CHARACT

private static final Set<Collector.Characteristics> CHARACT

max

private final int max

comparator

private final Comparator<T> comparator

Constructor Detail

SmallestN

public SmallestN(int maxElements)

No comparator supplied: natural ordering is used.

Parameters:

maxElements - the maximum number of desired elements

SmallestN

public SmallestN(int maxElements,
                 Comparator<T> comparator)

Parameters:

maxElements - the maximum number of desired elements

comparator - the comparator to be used

Method Detail

supplier

public Supplier<MinMaxPriorityQueue<T>> supplier()

Specified by:

supplier in interface Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

accumulator

public BiConsumer<MinMaxPriorityQueue<T>,T> accumulator()

Specified by:

accumulator in interface Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

combiner

public BinaryOperator<MinMaxPriorityQueue<T>> combiner()

Specified by:

combiner in interface Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

finisher

public Function<MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>> finisher()

Specified by:

finisher in interface Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>

characteristics

public Set<Collector.Characteristics> characteristics()

Specified by:

characteristics in interface Collector<T,MinMaxPriorityQueue<T>,MinMaxPriorityQueue<T>>