/* * Copyright (c) 1997, 2003, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.lang.ref; /** * Weak reference objects, which do not prevent their referents from being * made finalizable, finalized, and then reclaimed. Weak references are most * often used to implement canonicalizing mappings. * * <p> Suppose that the garbage collector determines at a certain point in time * that an object is <a href="package-summary.html#reachability">weakly * reachable</a>. At that time it will atomically clear all weak references to * that object and all weak references to any other weakly-reachable objects * from which that object is reachable through a chain of strong and soft * references. At the same time it will declare all of the formerly * weakly-reachable objects to be finalizable. At the same time or at some * later time it will enqueue those newly-cleared weak references that are * registered with reference queues. * * @author Mark Reinhold * @since 1.2 */ public class WeakReference<T> extends Reference<T> { /** * Creates a new weak reference that refers to the given object. The new * reference is not registered with any queue. * * @param referent object the new weak reference will refer to */ public WeakReference(T referent) { super(referent); } /** * Creates a new weak reference that refers to the given object and is * registered with the given queue. * * @param referent object the new weak reference will refer to * @param q the queue with which the reference is to be registered, * or <tt>null</tt> if registration is not required */ public WeakReference(T referent, ReferenceQueue<? super T> q) { super(referent, q); } }