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Diffstat (limited to 'libjava/java/lang/ref/WeakReference.java')
-rw-r--r-- | libjava/java/lang/ref/WeakReference.java | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/libjava/java/lang/ref/WeakReference.java b/libjava/java/lang/ref/WeakReference.java new file mode 100644 index 00000000000..32d5b132c7c --- /dev/null +++ b/libjava/java/lang/ref/WeakReference.java @@ -0,0 +1,68 @@ +/* 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); + } +} |