Package org.zkoss.util

Class DualCollection<T>

java.lang.Object

java.util.AbstractCollection<T>

org.zkoss.util.DualCollection<T>

All Implemented Interfaces:

Serializable, Iterable<T>, Collection<T>

public class DualCollection<T>
extends AbstractCollection<T>
implements Serializable

A combination of two collections into a collection.

Since:

3.0.0

Author:

tomyeh

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
DualCollection(Collection<T> first, Collection<T> second)	Constructor.

Method Summary

Modifier and Type	Method	Description
static final <M> Collection<M>	combine(Collection<M> first, Collection<M> second)	Returns a collection by combining two collections.
Iterator<T>	iterator()
int	size()

Methods inherited from class java.util.AbstractCollection

add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Constructor Details

DualCollection

public DualCollection(Collection<T> first,
 Collection<T> second)

Constructor. It is better to use combine(java.util.Collection<M>, java.util.Collection<M>) instead of this method since it checks whether any of them is null or equals.

Method Details

combine

public static final <M> Collection<M> combine(Collection<M> first,
 Collection<M> second)

Returns a collection by combining two collections. It checks whether any of them is null, or equals. And, returns the non-null one if another is null. If both null, it returns null.

size

public int size()

Specified by:

size in interface Collection<T>

Specified by:

size in class AbstractCollection<T>

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Collection<T>

Specified by:

iterator in interface Iterable<T>

Specified by:

iterator in class AbstractCollection<T>