de.alpharogroup.collections

Class CollectionExtensions

java.lang.Object

de.alpharogroup.collections.CollectionExtensions

public final class CollectionExtensions
extends Object

The class CollectionExtensions is an extension class for use with Collection objects.

Constructor Summary

Constructors

Constructor and Description
CollectionExtensions()

Method Summary

Modifier and Type	Method and Description
static <T> void	difference(Collection<T> one, Collection<T> other) Removes all of the first given collection's elements that are also contained in the second given collection.
static <T> int	hashCode(Collection<T[]> arrayObjects) Returns a hash code based on the contents of the collection that contains array objects.
static <T> Collection<T>	intersection(Collection<T>... toIntersect) Intersection of the given collections.
static <T> boolean	isEmpty(Collection<T> collection) Checks if the given Collection is null or empty.
static <T> boolean	isEqualCollection(Collection<T> one, Collection<T> other) Compare the given two Collection objects in equality.
static <T> boolean	isNotEmpty(Collection<T> collection) Checks if the given Collection is not null or empty
static <T> Collection<List<T>>	partition(Collection<T> collection, int size) Groups the given Collection to parts from the specified size.
static <T> Optional<Boolean>	preconditionOfEqualCollection(Collection<T> one, Collection<T> other) Checks the given two Collection objects if there are null and return the appropriate Optional boolean value

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionExtensions

public CollectionExtensions()

Method Detail

isEqualCollection

public static <T> boolean isEqualCollection(Collection<T> one,
                                            Collection<T> other)

Compare the given two Collection objects in equality.

Type Parameters:

T - the generic type of the elements

Parameters:

one - the one

other - the other

Returns:

true, if the given two Collection objects are equal otherwise false

preconditionOfEqualCollection

public static <T> Optional<Boolean> preconditionOfEqualCollection(Collection<T> one,
                                                                  Collection<T> other)

Checks the given two Collection objects if there are null and return the appropriate Optional boolean value

Type Parameters:

T - the generic type of the elements

Parameters:

one - the one

other - the other

Returns:

the Optional boolean if value is true both are null, if value is false given two Collection objects are not equal otherwise the Optional is empty

difference

public static <T> void difference(Collection<T> one,
                                  Collection<T> other)

Removes all of the first given collection's elements that are also contained in the second given collection.

Type Parameters:

T - the generic type

Parameters:

one - the collection where the element will be removed if any containing elements exists

other - collection containing elements to be removed from the first given collection

intersection

@SafeVarargs
public static <T> Collection<T> intersection(Collection<T>... toIntersect)

Intersection of the given collections. Internally this method uses the Collection.retainAll(Collection) for come to the result.

Type Parameters:

T - the generic type

Parameters:

toIntersect - the to intersect

Returns:

the result of the intersection. This will be the first collection that contains the result.

isNotEmpty

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

Checks if the given Collection is not null or empty

Type Parameters:

T - the generic type

Parameters:

collection - The collection to check

Returns:

true if the given Collection is null or empty otherwise false

isEmpty

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

Checks if the given Collection is null or empty.

Type Parameters:

T - the generic type

Parameters:

collection - The collection to check

Returns:

true if the given Collection is null or empty otherwise false.

hashCode

public static <T> int hashCode(Collection<T[]> arrayObjects)

Returns a hash code based on the contents of the collection that contains array objects.

Type Parameters:

T - the generic type of the array objects

Parameters:

arrayObjects - the collection that contains array objects whose content-based hash code to compute

Returns:

the content-based hash code for the given collection that contains array objects

partition

public static <T> Collection<List<T>> partition(Collection<T> collection,
                                                int size)

Groups the given Collection to parts from the specified size.

Type Parameters:

T - the generic type

Parameters:

collection - the collection

size - the size

Returns:

the collection