org.apache.sshd.common.util

Class MapEntryUtils

java.lang.Object

org.apache.sshd.common.util.MapEntryUtils

public final class MapEntryUtils
extends Object

Represents an un-modifiable pair of values

Author:

Apache MINA SSHD Project

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MapEntryUtils.EnumMapBuilder<K extends Enum<K>,V>
static class	MapEntryUtils.GenericMapPopulator<K,V,M extends Map<K,V>>
static class	MapEntryUtils.MapBuilder<K,V>
static class	MapEntryUtils.NavigableMapBuilder<K,V>

Method Summary

Modifier and Type	Method and Description
static <K extends Comparable<K>,V> Comparator<Map.Entry<K,V>>	byKeyEntryComparator()
static <V> Supplier<NavigableMap<String,V>>	caseInsensitiveMap()
static <K,V,M extends Map<V,K>> M	flipMap(Map<? extends K,? extends V> map, Supplier<? extends M> mapCreator, boolean allowDuplicates) Flips between keys and values of an input map
static boolean	isEmpty(Map<?,?> m)
static boolean	isNotEmpty(Map<?,?> m)
static <K,V,M extends Map<K,V>> M	mapValues(Function<? super V,? extends K> keyMapper, Supplier<? extends M> mapCreator, Collection<? extends V> values) Creates a map out of a group of values
static <K,V,M extends Map<K,V>> M	mapValues(Function<? super V,? extends K> keyMapper, Supplier<? extends M> mapCreator, V... values)
static int	size(Map<?,?> m)
static <T> BinaryOperator<T>	throwingMerger()
static <T,K,U> Collector<T,?,NavigableMap<K,U>>	toSortedMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, Comparator<? super K> comparator)
static <T,K,U> NavigableMap<K,U>	toSortedMap(Iterable<? extends T> values, Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper, Comparator<? super K> comparator)

Methods inherited from class java.lang.Object

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

Method Detail

byKeyEntryComparator

public static <K extends Comparable<K>,V> Comparator<Map.Entry<K,V>> byKeyEntryComparator()

Type Parameters:

K - The Comparable key type

V - The associated entry value

Returns:

A Comparator for Map.Entry-ies that compares the key values

size

public static int size(Map<?,?> m)

isEmpty

public static boolean isEmpty(Map<?,?> m)

isNotEmpty

public static boolean isNotEmpty(Map<?,?> m)

caseInsensitiveMap

public static <V> Supplier<NavigableMap<String,V>> caseInsensitiveMap()

Type Parameters:

V - Type of mapped value

Returns:

A Supplier that returns a new NavigableMap whenever its get() method is invoked

flipMap

public static <K,V,M extends Map<V,K>> M flipMap(Map<? extends K,? extends V> map,
                                                 Supplier<? extends M> mapCreator,
                                                 boolean allowDuplicates)

Flips between keys and values of an input map

Type Parameters:

K - Original map key type

V - Original map value type

M - Flipped map type

Parameters:

map - The original map to flip

mapCreator - The creator of the target map

allowDuplicates - Whether to ignore duplicates on flip

Returns:

The flipped map result

Throws:

IllegalArgumentException - if allowDuplicates is false and a duplicate value found in the original map.

mapValues

@SafeVarargs
public static <K,V,M extends Map<K,V>> M mapValues(Function<? super V,? extends K> keyMapper,
                                                                Supplier<? extends M> mapCreator,
                                                                V... values)

mapValues

public static <K,V,M extends Map<K,V>> M mapValues(Function<? super V,? extends K> keyMapper,
                                                   Supplier<? extends M> mapCreator,
                                                   Collection<? extends V> values)

Creates a map out of a group of values

Type Parameters:

K - The key type

V - The value type

M - The result Map type

Parameters:

keyMapper - The Function that generates a key for a given value. If the returned key is null then the value is not mapped

mapCreator - The Supplier used to create/retrieve the result map - provided non-empty group of values

values - The values to be mapped

Returns:

The resulting Map - Note: no validation is made to ensure that 2 (or more) values are not mapped to the same key

toSortedMap

public static <T,K,U> NavigableMap<K,U> toSortedMap(Iterable<? extends T> values,
                                                    Function<? super T,? extends K> keyMapper,
                                                    Function<? super T,? extends U> valueMapper,
                                                    Comparator<? super K> comparator)

toSortedMap

public static <T,K,U> Collector<T,?,NavigableMap<K,U>> toSortedMap(Function<? super T,? extends K> keyMapper,
                                                                   Function<? super T,? extends U> valueMapper,
                                                                   Comparator<? super K> comparator)

throwingMerger

public static <T> BinaryOperator<T> throwingMerger()