001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005  This file is part of Granite Data Services.
006
007  Granite Data Services is free software; you can redistribute it and/or modify
008  it under the terms of the GNU Library General Public License as published by
009  the Free Software Foundation; either version 2 of the License, or (at your
010  option) any later version.
011
012  Granite Data Services is distributed in the hope that it will be useful, but
013  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015  for more details.
016
017  You should have received a copy of the GNU Library General Public License
018  along with this library; if not, see <http://www.gnu.org/licenses/>.
019*/
020
021package org.granite.clustering;
022
023import java.io.Serializable;
024
025/**
026 * This class holds a <tt>transient</tt> reference to the object given to its
027 * constructor. When this class is serialized, the reference to the object is
028 * lost.
029 * 
030 * @author Franck WOLFF
031 * 
032 * @see org.granite.messaging.webapp.ServletGraniteContext
033 * @see TransientReference
034 */
035public final class TransientReferenceHolder implements Serializable {
036
037        private static final long serialVersionUID = 1L;
038        
039        private final transient Object object;
040        
041        public TransientReferenceHolder(Object object) {
042                this.object = object;
043        }
044
045        public Object get() {
046                return object;
047        }
048
049        @Override
050        public boolean equals(Object obj) {
051                if (this == obj)
052                        return true;
053                if (!(obj instanceof TransientReferenceHolder))
054                        return false;
055                Object reference = ((TransientReferenceHolder)obj).get();
056                if (reference == object)
057                        return true;
058                if (object == null)
059                        return false; 
060                return object.equals(reference);
061        }
062
063        @Override
064        public int hashCode() {
065                if (object != null)
066                        return object.hashCode();
067                return 0;
068        }
069
070        @Override
071        public String toString() {
072                return getClass().getName() + ": " + object;
073        }
074}