| /* java.lang.ref.WeakReference |
| Copyright (C) 1999 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| As a special exception, if you link this library with other files to |
| produce an executable, this library does not by itself cause the |
| resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why the |
| executable file might be covered by the GNU General Public License. */ |
| |
| |
| package java.lang.ref; |
| |
| /** |
| * A weak reference will be cleared, if the object is only weakly |
| * reachable. It is useful for lookup tables, where you aren't |
| * interested in an entry, if the key isn't reachable anymore. |
| * <code>WeakHashtable</code> is a complete implementation of such a |
| * table. <br> |
| * |
| * It is also useful to make objects unique: You create a set of weak |
| * references to those objects, and when you create a new object you |
| * look in this set, if the object already exists and return it. If |
| * an object is not referenced anymore, the reference will |
| * automatically cleared, and you may remove it from the set. <br> |
| * |
| * @author Jochen Hoenicke |
| * @see java.util.WeakHashtable |
| */ |
| public class WeakReference |
| extends Reference |
| { |
| /** |
| * Create a new weak reference, that is not registered to any queue. |
| * @param referent the object we refer to. |
| */ |
| public WeakReference(Object referent) |
| { |
| super(referent); |
| } |
| |
| /** |
| * Create a new weak reference. |
| * @param referent the object we refer to. |
| * @param q the reference queue to register on. |
| * @exception NullPointerException if q is null. |
| */ |
| public WeakReference(Object referent, ReferenceQueue q) |
| { |
| super(referent, q); |
| } |
| } |