Package com.vividsolutions.jump.util

Class CollectionUtil

java.lang.Object

com.vividsolutions.jump.util.CollectionUtil

public class CollectionUtil
extends Object

Constructor Summary

Constructors

Constructor	Description
CollectionUtil()

Method Summary

Modifier and Type	Method	Description
static void	addIfNotNull(Object item, Collection collection)
static <T,R> Collection<R>	collect(Collection<T> collection, Block block)	The Smalltalk #collect method.
static <T> List<List<T>>	combinations(List<T> original)	Returns a List of Lists: all combinations of the elements of the given List.
static <T> List<List<T>>	combinations(List<T> original, int maxCombinationSize, T mandatoryItem)	Returns a List of Lists: all combinations of the elements of the given List.
static List	combinations(List original, int maxCombinationSize)	Returns a List of Lists: all combinations of the elements of the given List.
static <T> Collection<T>	concatenate(Collection<? extends Collection<T>> collections)
static <T> Collection<T>	concatenate(Collection<T> a, Collection<T> b)
static boolean	containsReference(Object[] objects, Object o)
static Map<Object,Object>	createMap(Class mapClass, Object[] alternatingKeysAndValues)
static Map	createMap(Object[] alternatingKeysAndValues)
static Collection	filterByClass(Collection collection, Class c)	Modifies and returns the collection.
static Object	get(Class<?> c, Map<Class<?>,? extends Object> map)	Search an object associated to the class c or one of its parent in the associative map
static Object	ifNotIn(Object o, Collection c, Object alternative)
static int	indexOf(Object o, Object[] objects)
static <U,V> Map<V,U>	inverse(Map<U,V> map)
static List[]	keysAndCorrespondingValues(Map map)	The nth key corresponds to the nth value
static <T> List<T>	list(T a, T b)
static Object	randomElement(List list)
static <T> Collection<T>	removeDuplicates(Collection<T> original)	Brute force, for when HashSet and TreeSet won't work (e.g.
static <U,V> void	removeKeys(Collection<U> keys, Map<U,V> map)
static void	resize(List list, int newSize)
static List	reverse(List list)
static SortedSet<Integer>	reverseSortedSet(int[] ints)
static <T> Collection<T>	select(Collection<T> collection, Block block)	The Smalltalk #select method.
static void	setIfNull(int i, List<String> list, String value)
static <T> Collection	stretch(Collection<T> source, Collection<T> destination, int destinationSize)	Data is evenly discarded or duplicated to attain the new size

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionUtil

public CollectionUtil()

Method Detail

concatenate

public static <T> Collection<T> concatenate(Collection<T> a,
                                            Collection<T> b)

list

public static <T> List<T> list(T a,
                               T b)

combinations

public static List combinations(List original,
                                int maxCombinationSize)

Returns a List of Lists: all combinations of the elements of the given List.

Parameters:

maxCombinationSize - combinations larger than this value are discarded

inverse

public static <U,V> Map<V,U> inverse(Map<U,V> map)

combinations

public static <T> List<List<T>> combinations(List<T> original,
                                             int maxCombinationSize,
                                             T mandatoryItem)

Returns a List of Lists: all combinations of the elements of the given List.

Parameters:

maxCombinationSize - combinations larger than this value are discarded

mandatoryItem - an item that all returned combinations must contain, or null to leave unspecified

combinations

public static <T> List<List<T>> combinations(List<T> original)

Returns a List of Lists: all combinations of the elements of the given List.

removeKeys

public static <U,V> void removeKeys(Collection<U> keys,
                                          Map<U,V> map)

keysAndCorrespondingValues

public static List[] keysAndCorrespondingValues(Map map)

The nth key corresponds to the nth value

concatenate

public static <T> Collection<T> concatenate(Collection<? extends Collection<T>> collections)

randomElement

public static Object randomElement(List list)

reverseSortedSet

public static SortedSet<Integer> reverseSortedSet(int[] ints)

reverse

public static List reverse(List list)

stretch

public static <T> Collection stretch(Collection<T> source,
                                     Collection<T> destination,
                                     int destinationSize)

Data is evenly discarded or duplicated to attain the new size

ifNotIn

public static Object ifNotIn(Object o,
                             Collection c,
                             Object alternative)

setIfNull

public static void setIfNull(int i,
                             List<String> list,
                             String value)

resize

public static void resize(List list,
                          int newSize)

containsReference

public static boolean containsReference(Object[] objects,
                                        Object o)

indexOf

public static int indexOf(Object o,
                          Object[] objects)

removeDuplicates

public static <T> Collection<T> removeDuplicates(Collection<T> original)

Brute force, for when HashSet and TreeSet won't work (e.g. #hashCode implementation isn't appropriate). The original Collection is not modified.

addIfNotNull

public static void addIfNotNull(Object item,
                                Collection collection)

filterByClass

public static Collection filterByClass(Collection collection,
                                       Class c)

Modifies and returns the collection.

createMap

public static Map createMap(Object[] alternatingKeysAndValues)

createMap

public static Map<Object,Object> createMap(Class mapClass,
                                                 Object[] alternatingKeysAndValues)

collect

public static <T,R> Collection<R> collect(Collection<T> collection,
                                                Block block)

The Smalltalk #collect method.

select

public static <T> Collection<T> select(Collection<T> collection,
                                       Block block)

The Smalltalk #select method.

get

public static Object get(Class<?> c,
                         Map<Class<?>,? extends Object> map)

Search an object associated to the class c or one of its parent in the associative map

Parameters:

c - the class used as a key

map - the associative map in which the research is made

Returns:

an object or null if no object is associated to class c or one of its parent