Class PhantomReference<T>

public class PhantomReference<T>
extends Reference<T>

A phantom reference is useful, to get notified, when an object got finalized. You can't access that object though, since it is finalized. This is the reason, why get() always returns null.

Constructor Summary

PhantomReference(T referent, T> q)
Creates a new phantom reference.

Method Summary

Returns the object, this reference refers to.

Methods inherited from class java.lang.ref.Reference<T>

clear, enqueue, get, isEnqueued

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details


public PhantomReference(T referent,
                        T> q)
Creates a new phantom reference.
referent - the object that should be watched.
q - the queue that should be notified, if the referent was finalized. This mustn't be null.
NullPointerException - if q is null.

Method Details


public T get()
Returns the object, this reference refers to.
get in interface Reference<T>
null, since the refered object may be finalized and thus not accessible.

java.lang.ref.PhantomReference Copyright (C) 1999, 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.