JavaTM 2 Platform
Standard Edition

java.lang.ref
Class WeakReference

java.lang.Object
  |
  +--java.lang.ref.Reference
        |
        +--java.lang.ref.WeakReference

public class WeakReference
extends Reference

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.

Suppose that the garbage collector determines at a certain point in time that an object is weakly reachable. 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.

Since:
JDK1.2

Constructor Summary
WeakReference(Object referent)
          Creates a new weak reference that refers to the given object.
WeakReference(Object referent, ReferenceQueue q)
          Creates a new weak reference that refers to the given object and is registered with the given queue.
 
Methods inherited from class java.lang.ref.Reference
clear, enqueue, get, isEnqueued
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

WeakReference

public WeakReference(Object referent)
Creates a new weak reference that refers to the given object. The new reference is not registered with any queue.

WeakReference

public WeakReference(Object referent,
                     ReferenceQueue q)
Creates a new weak reference that refers to the given object and is registered with the given queue.
Throws:
NullPointerException - If the queue argument is null

JavaTM 2 Platform
Standard Edition

Submit a bug or feature
Java, Java 2D, and JDBC are a trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries.
Copyright 1993-1999 Sun Microsystems, Inc. 901 San Antonio Road,
Palo Alto, California, 94303, U.S.A. All Rights Reserved.