Package org.opendaylight.yangtools.util

Class CollectionWrappers

java.lang.Object

org.opendaylight.yangtools.util.CollectionWrappers

@Beta
@NonNullByDefault
public final class CollectionWrappers
extends Object

Utility class for adapting a Collections to Sets and Lists.

Author:

Robert Varga

Method Summary

Modifier and Type	Method	Description
static <E> List<E>	wrapAsList(Collection<E> collection)	Wrap the specified Collection as a List.
static <E> Set<E>	wrapAsSet(Collection<E> collection)	Wrap the specified Collection as a Set.

Methods inherited from class java.lang.Object

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

Method Details

wrapAsList

public static <E> List<E> wrapAsList(Collection<E> collection)

Wrap the specified Collection as a List. If the collection is already a List, it is wrapped in a Collections.unmodifiableList(List) to prevent mutability leaking. If the collection is determined to be empty, an empty list is returned instead. If the collection is a known-immutable implementation of List interface, it is returned unwrapped. Backing collection is required to be effectively immutable. If this requirement is violated, the returned object may behave in unpredictable ways.

Type Parameters:

E - the type of elements in the collection

Parameters:

collection - Collection to be wrapped

Returns:

An effectively-immutable wrapper of the collection.

Throws:

NullPointerException - if collection is null

wrapAsSet

public static <E> Set<E> wrapAsSet(Collection<E> collection)

Wrap the specified Collection as a Set. If the collection is already a Set, it is wrapped in a Collections.unmodifiableSet(Set) to prevent mutability leaking. If the collection is determined to be empty, an empty set is returned instead. If the collection is a known-immutable implementation of Set interface, it is returned unwrapped. The collection is checked for duplicates at instantiation time, such that it effectively implements the Set contract. Backing collection is required to be effectively immutable. If this requirement is violated, the returned object may behave in unpredictable ways.

Type Parameters:

E - the type of elements in the collection

Parameters:

collection - Collection to be wrapped

Returns:

An effectively-immutable wrapper of the collection.

Throws:

NullPointerException - if collection is null or any of its elements is null

IllegalArgumentException - if the collection's contents do not conform to the Set contract