sun.com/j2se/1.4/docs/api/java/util/WeakHashMap.html">
WeakHashMap
. However, you can also specify hard keys and weak values, or any other combination. The default constructor uses hard keys and soft values, providing a memory-sensitive cache.
This map is similar to {@link org.apache.commons.collections.map.ReferenceIdentityMap ReferenceIdentityMap}. It differs in that keys and values in this class are compared using equals()
.
This {@link Map} implementation does not allow null elements.Attempting to add a null key or value to the map will raise a NullPointerException
.
This implementation is not synchronized. You can use {@link java.util.Collections#synchronizedMap} to provide synchronized access to a ReferenceMap
. Remember that synchronization will not stop the garbage collecter removing entries.
All the available iterators can be reset back to the start by casting to ResettableIterator
and calling reset()
.
NOTE: As from Commons Collections 3.1 this map extends AbstractReferenceMap
(previously it extended AbstractMap). As a result, the implementation is now extensible and provides a MapIterator
.
@see java.lang.ref.Reference
@since Commons Collections 3.0 (previously in main package v2.1)
@version $Revision: 1.13 $ $Date: 2004/04/27 21:35:23 $
@author Paul Jack
@author Stephen Colebourne