com.silverpeas.util
Class CollectionUtil

java.lang.Object
  com.silverpeas.util.CollectionUtil

public class CollectionUtil
extends Object

Author:

Yohann Chastagnier

Constructor Summary

CollectionUtil()

Method Summary

static <T> boolean	addAllIgnoreNull(Collection<? super T> c, T... elements) Null elements are not taking into account.
static <T> List<T>	asList(T... values)
static <T> Set<T>	asSet(T... values)
static <T> Collection<T>	extractFrom(Class<T> aClass, Collection<?> collection, String propertyName) Extracting a property.
static <T> Collection<T>	extractFrom(Class<T> aClass, Collection<?> collection, String propertyNameToExtract, String propertyNameToCompare, Object givenValueToCompare, boolean nullValueExtracted) Extracting a property from elements that each has an other property with a given value
static <T> Collection<T>	extractFrom(Collection<?> collection, String propertyName) Extracting a property.
static <T> Collection<T>	extractFrom(Collection<?> collection, String propertyName, boolean isListOfArray, int numberColumn) Extracting a property.
static <T> List<T>	intersection(List<T> list1, List<T> list2) Makes an intersection betwwen both of the given lists.
static <T> boolean	isEmpty(Collection<T> collection) Checks if the given collection is not instancied or empty
static <T> boolean	isNotEmpty(Collection<T> collection) Checks if the given collection is instancied and not empty
static <T,K,V> HashMap<K,V>	listToMap(Collection<T> collection, ExtractionList<T,K,V> extractor) Transforming a collection into a map
static <T> List<T>	reverse(List<T> list) Reverse the given list and returns it.
static <T> Collection<Collection<T>>	split(Collection<T> collection) Splits a collection into several collections.
static <T> Collection<Collection<T>>	split(Collection<T> collection, int collectionSizeMax) Splits a collection into several collections.
static <T> List<T>	union(List<T> list1, List<T> list2) Makes an union between both of the given lists.

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

reverse

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

Reverse the given list and returns it.

Type Parameters:

T -

Parameters:

list -

Returns:

isEmpty

public static <T> boolean isEmpty(Collection<T> collection)

Checks if the given collection is not instancied or empty

Type Parameters:

T -

Parameters:

collection -

Returns:

isNotEmpty

public static <T> boolean isNotEmpty(Collection<T> collection)

Checks if the given collection is instancied and not empty

Type Parameters:

T -

Parameters:

collection -

Returns:

split

public static <T> Collection<Collection<T>> split(Collection<T> collection)

Splits a collection into several collections. (Particularly useful for limitations of database around the "in" clause)

Parameters:

collection -

Returns:

split

public static <T> Collection<Collection<T>> split(Collection<T> collection,
                                                  int collectionSizeMax)

Splits a collection into several collections. (Particularly useful for limitations of database around the "in" clause)

Parameters:

collection -

collectionSizeMax -

Returns:

listToMap

public static <T,K,V> HashMap<K,V> listToMap(Collection<T> collection,
                                             ExtractionList<T,K,V> extractor)

Transforming a collection into a map

Type Parameters:

T - collection type elements

K - map type key

V - map type value

Parameters:

collection -

extractor - extractor interface

Returns:

a map initialized from a list by an extractor

extractFrom

public static <T> Collection<T> extractFrom(Class<T> aClass,
                                            Collection<?> collection,
                                            String propertyName)

Extracting a property.

Parameters:

aClass - property class to extract

collection - collection from that to extract

propertyName - name of the property

Returns:

a collection with requested elements

extractFrom

public static <T> Collection<T> extractFrom(Collection<?> collection,
                                            String propertyName)

Extracting a property.

Parameters:

collection - collection from that to extract

propertyName - name of the property

Returns:

a collection with requested elements

extractFrom

public static <T> Collection<T> extractFrom(Collection<?> collection,
                                            String propertyName,
                                            boolean isListOfArray,
                                            int numberColumn)

Extracting a property.

Parameters:

collection - collection from that to extract

propertyName - name of the property

isListOfArray - indicates if the list is an array list

numberColumn - column index to extract from the array

Returns:

a collection with requested elements

extractFrom

public static <T> Collection<T> extractFrom(Class<T> aClass,
                                            Collection<?> collection,
                                            String propertyNameToExtract,
                                            String propertyNameToCompare,
                                            Object givenValueToCompare,
                                            boolean nullValueExtracted)

Extracting a property from elements that each has an other property with a given value

Parameters:

class - property class to extract

collection - element collection

propertyNameToExtract - name property to extract

propertyNameToCompare - name value to compare

givenValueToCompare - value to compare

nullValueExtracted - null value extracted

Returns:

a bean property collection

asList

public static <T> List<T> asList(T... values)

asSet

public static <T> Set<T> asSet(T... values)

addAllIgnoreNull

public static <T> boolean addAllIgnoreNull(Collection<? super T> c,
                                           T... elements)

Null elements are not taking into account.

See Also:

Collections.addAll(java.util.Collection, Object[])

union

public static <T> List<T> union(List<T> list1,
                                List<T> list2)

Makes an union between both of the given lists.
The result contains unique values.

Type Parameters:

T -

Parameters:

list1 - the first list.

list2 - the second list.

Returns:

the union between the two lists.

intersection

public static <T> List<T> intersection(List<T> list1,
                                       List<T> list2)

Makes an intersection betwwen both of the given lists.
The result contains unique values.

Type Parameters:

T -

Parameters:

list1 - the first list.

list2 - the second list.

Returns:

the intersection between the two lists.