Package org.silverpeas.core.util

Class CollectionUtil

java.lang.Object

org.silverpeas.core.util.CollectionUtil

public class CollectionUtil
extends Object

Author:

Yohann Chastagnier

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CollectionUtil.RuptureContext<T>	Handles the context of a rupture treatment. It must by initialized by calling CollectionUtil.RuptureContext.newOne(List) after using findNextRupture(RuptureContext, Predicate). Callers can verify if it is no more possible to get an element from the rupture by calling CollectionUtil.RuptureContext.isTerminated().

Method Summary

Modifier and Type	Method	Description
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> Optional<T>	findFirst(List<T> list, Predicate<T> predicate)	Gets the optional first element in the given List which matches the given predicate.
static <T> Optional<T>	findFirst(List<T> list, Predicate<T> predicate, int firstIndex)	Gets the optional first element in the given List which matches the given predicate and the position is at or after the first given index.
static <T> Optional<T>	findNextRupture(CollectionUtil.RuptureContext<T> context, Predicate<T> predicate)	Gets the optional next element in the given ordered List which matches the given CollectionUtil.RuptureContext which must be intialized by calling CollectionUtil.RuptureContext.newOne(List).
static <T> int	indexOf(List<T> list, Predicate<T> predicate)	Finds the first index in the given List which matches the given predicate.
static <T> int	indexOf(List<T> list, Predicate<T> predicate, int firstIndex)	Finds the first index in the given List which matches the given predicate.
static <T> Collection<T>	intersection(Collection<T> col1, Collection<T> col2)	Makes an intersection between both of the given collections. The result contains unique values.
static <T> Collection<T>	intersection(Collection<T> col1, Collection<T> col2, Function<T,Object> discriminator)	Makes an intersection between both of the given collections. The result contains unique values.
static <T> List<T>	intersection(List<T> list1, List<T> list2)	Makes an intersection between both of the given lists. The result contains unique values.
static <T> List<T>	intersection(List<T> list1, List<T> list2, Function<T,Object> discriminator)	Makes an intersection between both of the given lists. The result contains unique values.
static <T> boolean	isEmpty(Collection<T> collection)	Checks if the given collection is not instanced or empty
static <T> boolean	isNotEmpty(Collection<T> collection)	Checks if the given collection is instanced and not empty
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<List<T>>	splitList(List<T> collection)	Splits a collection into several collections.
static <T> Collection<T>	union(Collection<T> col1, Collection<T> col2)	Makes an union between both of the given collections. The result contains unique values.
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.

Methods inherited from class java.lang.Object

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

Method Detail

reverse

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

Reverse the given list and returns it.

Type Parameters:

T - the type of the instance contained into the specified list

Parameters:

list - the list to reverse

Returns:

the specified list that has been reversed (same instance)

isEmpty

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

Checks if the given collection is not instanced or empty

Type Parameters:

T - the type of the instance contained into the specified collection

Parameters:

collection - the collection to verify

Returns:

true if specified collection is empty, false otherwise

isNotEmpty

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

Checks if the given collection is instanced and not empty

Type Parameters:

T - the type of the instance contained into the specified collection

Parameters:

collection - the collection to verify

Returns:

true if specified collection is not empty, false otherwise

splitList

public static <T> List<List<T>> splitList(List<T> collection)

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

Type Parameters:

T - the concrete type of the items in the list.

Parameters:

collection - the collection to split

Returns:

the slices of the specified collection

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)

Type Parameters:

T - the concrete type of the items in the collection.

Parameters:

collection - the collection to split

Returns:

the slices of the specified collection

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)

Type Parameters:

T - the concrete type of the items in the collection.

Parameters:

collection - the collection to split

collectionSizeMax - the maximum elements in slice

Returns:

the slices of the specified collection

asList

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

asSet

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

addAllIgnoreNull

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

Null elements are not taking into account.

Type Parameters:

T - the concrete type of the items.

Parameters:

c - collection in which the items will be added

elements - the items to add

Returns:

true of the items are added, false otherwise.

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 - the type of the items in the list.

Parameters:

list1 - the first list.

list2 - the second list.

Returns:

the union between the two lists.

union

public static <T> Collection<T> union(Collection<T> col1,
                                      Collection<T> col2)

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

Type Parameters:

T - the type of the items in the list

Parameters:

col1 - the first collection.

col2 - the second collection.

Returns:

the union between the two collections.

intersection

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

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

Type Parameters:

T - the type of the items in the list

Parameters:

list1 - the first list.

list2 - the second list.

Returns:

the intersection between the two lists.

intersection

public static <T> Collection<T> intersection(Collection<T> col1,
                                             Collection<T> col2)

Makes an intersection between both of the given collections.
The result contains unique values.

Type Parameters:

T - the type of the items in the list

Parameters:

col1 - the first collection.

col2 - the second collection.

Returns:

the intersection between the two collections.

intersection

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

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

Type Parameters:

T - the type of the items in the list

Parameters:

list1 - the first list.

list2 - the second list.

discriminator - get the discriminator data.

Returns:

the intersection between the two lists.

intersection

public static <T> Collection<T> intersection(Collection<T> col1,
                                             Collection<T> col2,
                                             Function<T,Object> discriminator)

Makes an intersection between both of the given collections.
The result contains unique values.

Type Parameters:

T - the type of the items in the list

Parameters:

col1 - the first collection.

col2 - the second collection.

discriminator - get the discriminator data.

Returns:

the intersection between the two collections.

indexOf

public static <T> int indexOf(List<T> list,
                              Predicate<T> predicate)

Finds the first index in the given List which matches the given predicate.

Type Parameters:

T - the type of the items in the list

Parameters:

list - the List to search, may not be null.

predicate - the predicate to use, may not be null.

Returns:

the first index of an Object in the List which matches the predicate.

indexOf

public static <T> int indexOf(List<T> list,
                              Predicate<T> predicate,
                              int firstIndex)

Finds the first index in the given List which matches the given predicate.

Type Parameters:

T - the type of the items in the list

Parameters:

list - the List to search, may not be null.

predicate - the predicate to use, may not be null.

firstIndex - an integer representing the first index from which the search starts.

Returns:

the first index of an Object in the List which matches the predicate.

findFirst

public static <T> Optional<T> findFirst(List<T> list,
                                        Predicate<T> predicate)

Gets the optional first element in the given List which matches the given predicate.

Type Parameters:

T - the type of the items in the list

Parameters:

list - the List to search, may not be null.

predicate - the predicate to use, may not be null.

Returns:

the optional Object in the List which matches the predicate.

findFirst

public static <T> Optional<T> findFirst(List<T> list,
                                        Predicate<T> predicate,
                                        int firstIndex)

Gets the optional first element in the given List which matches the given predicate and the position is at or after the first given index.

Type Parameters:

T - the type of the items in the list

Parameters:

list - the List to search, may not be null.

predicate - the predicate to use, may not be null.

firstIndex - an integer representing the first index from which the search starts.

Returns:

the optional Object in the List which matches the predicate.

findNextRupture

public static <T> Optional<T> findNextRupture(CollectionUtil.RuptureContext<T> context,
                                              Predicate<T> predicate)

Gets the optional next element in the given ordered List which matches the given CollectionUtil.RuptureContext which must be intialized by calling CollectionUtil.RuptureContext.newOne(List).

Type Parameters:

T - the type of the items in the list

Parameters:

context - the context of the rupture.

predicate - the predicate to use, may not be null.

Returns:

the first index of an Object in the List which matches the predicate.