001/* java.lang.ref.SoftReference 002 Copyright (C) 1999, 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.lang.ref; 040 041/** 042 * A soft reference will be cleared, if the object is only softly 043 * reachable and the garbage collection needs more memory. The garbage 044 * collection will use an intelligent strategy to determine which soft 045 * references it should clear. This makes a soft reference ideal for 046 * caches.<br> 047 * 048 * @author Jochen Hoenicke 049 */ 050public class SoftReference<T> 051 extends Reference<T> 052{ 053 /** 054 * Create a new soft reference, that is not registered to any queue. 055 * @param referent the object we refer to. 056 */ 057 public SoftReference(T referent) 058 { 059 super(referent); 060 } 061 062 /** 063 * Create a new soft reference. 064 * @param referent the object we refer to. 065 * @param q the reference queue to register on. 066 * @exception NullPointerException if q is null. 067 */ 068 public SoftReference(T referent, ReferenceQueue<? super T> q) 069 { 070 super(referent, q); 071 } 072 073 /** 074 * Returns the object, this reference refers to. 075 * @return the object, this reference refers to, or null if the 076 * reference was cleared. 077 */ 078 public T get() 079 { 080 /* Why is this overloaded??? 081 * Maybe for a kind of LRU strategy. */ 082 return super.get(); 083 } 084}