Package org.castor.cache.hashbelt.container

Class WeakReferenceContainer

java.lang.Object
org.castor.cache.hashbelt.container.WeakReferenceContainer
All Implemented Interfaces:
Map<Object,Object>, Container
public final class WeakReferenceContainer extends Object implements Container
An implementation of a container that uses weak references for storing values in the map, so that values can be removed from the map by the system when the system is under memory pressure. Keys, however, are kept strong - so contains() may well find an element, but the value may have been lost. Make sure you test for null returns from put.

Note that keys are hard references; in a situation where OutOfMemory will occur, the JVM will first wipe out all unreferenced objects whose only link is a weak reference. An out of memory will wipe all values from the maps which are currently unreferenced. The keys remain until the hashbelt containers are garbage collected, an put is called with that key or when the value should be accessed through any operation of the Container interface.

Since:
1.0
Version:
$Revision: 8102 $ $Date: 2006-04-25 16:09:10 -0600 (Tue, 25 Apr 2006) $
Author:
Gregory Block, Ralf Joachim