Package org.kuali.coeus.s2sgen.impl.util

Class CollectionUtils

java.lang.Object

org.kuali.coeus.s2sgen.impl.util.CollectionUtils

public final class CollectionUtils
extends Object

Yet another collection utility. Contains methods that are not found in the apache util classes or the jdk util classes.

Method Summary

Modifier and Type	Method	Description
static <K, U> Collector<Map.Entry<K,U>,?,Map<K,U>>	entriesToMap()	Convenience method to a return a Collector that converts an Map.Entry to a Map.
static <K, U, M extends Map<K, U>> Collector<Map.Entry<K,U>,?,M>	entriesToMap(Supplier<M> mapSupplier)	Convenience method to a return a Collector that converts an Map.Entry to a Map which type is provided as a mapSupplier.
static <K, U> Collector<Map.Entry<K,U>,?,Map<K,U>>	entriesToMapWithReplacing()	Convenience method to a return a Collector that converts an Map.Entry to a Map.
static <K, V> Map.Entry<K,V>	entry(K key, V value)	Creates an entry from a key and value.
static <K, U> Collector<Map.Entry<K,U>,?,Map<K,U>>	nullSafeEntriesToMap()	Convenience method to a return a Collector that converts an Map.Entry to a Map.
static <T, K, U> Collector<T,?,Map<K,U>>	nullSafeToMap(Function<? super T,? extends K> keyMapper, Function<? super T,? extends U> valueMapper)	Null-safe replacement for Collectors.toMap.

Methods inherited from class java.lang.Object

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

Method Details

entry

public static <K,
V> Map.Entry<K,V> entry(K key,
 V value)

Creates an entry from a key and value.

Type Parameters:

K - the key type

V - the value type

Parameters:

key - the key. Can be null.

value - the value. Can be null.

Returns:

a Map.Entry

entriesToMap

public static <K,
U,
M extends Map<K,
U>>
Collector<Map.Entry<K,U>,?,M> entriesToMap(Supplier<M> mapSupplier)

Convenience method to a return a Collector that converts an Map.Entry to a Map which type is provided as a mapSupplier.

Type Parameters:

K - the key type

U - the value type

M - the map type

Parameters:

mapSupplier - supplies a new instance of a Map. cannot be null.

Returns:

A Collector from Map.Entry to Map as defined by the mapSupplier

entriesToMap

public static <K,
U>
Collector<Map.Entry<K,U>,?,Map<K,U>> entriesToMap()

Convenience method to a return a Collector that converts an Map.Entry to a Map.

Type Parameters:

K - the key type

U - the value type

Returns:

A Collector from Map.Entry to Map

entriesToMapWithReplacing

public static <K,
U>
Collector<Map.Entry<K,U>,?,Map<K,U>> entriesToMapWithReplacing()

Convenience method to a return a Collector that converts an Map.Entry to a Map. If a duplicate key is detected, the value is replaced rather throwing an exception as is the default behavior.

Type Parameters:

K - the key type

U - the value type

Returns:

A Collector from Map.Entry to Map

nullSafeEntriesToMap

public static <K,
U>
Collector<Map.Entry<K,U>,?,Map<K,U>> nullSafeEntriesToMap()

Convenience method to a return a Collector that converts an Map.Entry to a Map.

Type Parameters:

K - the key type

U - the value type

Returns:

A Collector from Map.Entry to Map

nullSafeToMap

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

Null-safe replacement for Collectors.toMap. Allows null keys and values. If a duplicate key is found, throws IllegalStateException

Parameters:

keyMapper - function to get the key from the items

valueMapper - function to get the value from the items

Returns:

A Collector from List to Map