org.zkoss.util
Class DualCollection

java.lang.Object
  java.util.AbstractCollection
      org.zkoss.util.DualCollection

All Implemented Interfaces:

Serializable, Iterable, Collection

public class DualCollection
extends AbstractCollection
implements Serializable

A combination of two collections into a collection.

Since:

3.0.0

Author:

tomyeh

See Also:

Serialized Form

Constructor Summary

DualCollection(Collection first, Collection second)
Constructor.

Method Summary

static Collection	combine(Collection first, Collection second) Returns a collection by combining two collections.
Iterator	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

Constructor Detail

DualCollection

public DualCollection(Collection first,
                      Collection second)

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

Method Detail

combine

public static final Collection combine(Collection first,
                                       Collection 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

Specified by:

size in class AbstractCollection

iterator

public Iterator iterator()

Specified by:

iterator in interface Iterable

Specified by:

iterator in interface Collection

Specified by:

iterator in class AbstractCollection