Package org.jboss.weld.util.collections

Class WeldCollections

java.lang.Object

org.jboss.weld.util.collections.WeldCollections

public class WeldCollections
extends Object

Collection utilities.

Author:

Jozef Hartinger

Method Summary

Modifier and Type	Method	Description
static <T> boolean	addIfNotNull(Collection<T> collection, T element)
static <T> List<T>	immutableListView(List<T> list)	Returns an immutable view of a given list.
static <K,V> Map<K,V>	immutableMapView(Map<K,V> map)	Returns an immutable view of a given map.
static <T> Set<T>	immutableSetView(Set<T> set)	Returns an immutable view of a given set.
static <K,V> V	putIfAbsent(Map<K,V> map, K key, V value)	Utility method for working with maps.
static <T> List<T>	sort(List<T> list, Comparator<? super T> comparator)	Fluent version of Collections.sort(List, Comparator)
static String	toMultiRowString(Collection<?> collection)	Returns the supplied collection as a multi-row string with every toString() of every element of the collection in its own row.

Methods inherited from class java.lang.Object

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

Method Detail

immutableSetView

public static <T> Set<T> immutableSetView(Set<T> set)

Returns an immutable view of a given set. If the given set is empty, a shared instance is returned. If the given set is an instance of ArraySet, it is trimmed.

immutableListView

public static <T> List<T> immutableListView(List<T> list)

Returns an immutable view of a given list. If the given list is empty, a shared instance is returned. If the given list is an instance of ArrayList, it is trimmed.

immutableMapView

public static <K,V> Map<K,V> immutableMapView(Map<K,V> map)

Returns an immutable view of a given map.

sort

public static <T> List<T> sort(List<T> list,
                               Comparator<? super T> comparator)

Fluent version of Collections.sort(List, Comparator)

toMultiRowString

public static String toMultiRowString(Collection<?> collection)

Returns the supplied collection as a multi-row string with every toString() of every element of the collection in its own row. Example: toMultiRowString(Arrays.asList("aaa", "bbb", "ccc")) will return:

   - aaa,
   - bbb,
   - ccc
 

addIfNotNull

public static <T> boolean addIfNotNull(Collection<T> collection,
                                       T element)

putIfAbsent

public static <K,V> V putIfAbsent(Map<K,V> map,
                                        K key,
                                        V value)

Utility method for working with maps. Unlike Map.putIfAbsent(Object, Object) this method always returns the value that ends up store in the map which is either the old value (if any was present) or the new value (if it was stored in the map).

Parameters:

map - the map

key - the key

value - the value

Returns:

the value that ends up store in the map which is either the old value (if any was present) or the new value (if it was stored in the map)