001    /*
002      Copyright (C) 2004 Laurent Martelli <laurent@aopsys.com>
003    
004      This program is free software; you can redistribute it and/or modify
005      it under the terms of the GNU Lesser General Public License as
006      published by the Free Software Foundation; either version 2 of the
007      License, or (at your option) any later version.
008    
009      This program is distributed in the hope that it will be useful,
010      but WITHOUT ANY WARRANTY; without even the implied warranty of
011      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
012      GNU Lesser General Public License for more details.
013    
014      You should have received a copy of the GNU Lesser General Public License
015      along with this program; if not, write to the Free Software
016      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
017    
018    package org.objectweb.jac.aspects.timestamp;
019    
020    import java.util.Hashtable;
021    import java.util.Iterator;
022    import java.util.Map.Entry;
023    import java.io.File;
024    
025    public class Timestamps {
026        Hashtable stamps = new Hashtable();
027    
028        /**
029         * Set the stamp of an object to current time
030         * @see #touch(Object)
031         */
032        public void touch(Object object) {
033            stamps.put(object,new Long(System.currentTimeMillis()));
034        }
035    
036        /**
037         * Gets the time an object was last modified, or 0.
038         *
039         * @param object the object whose timestamp you request
040         * @return if object is a file, obect.lastModified(), otherwise
041         * the stored timestamp for that object, or if 0 no timestamp is
042         * stored for it.
043         *
044         * @see #touch(Object) 
045         */
046        public long getStamp(Object object) {
047            if (object instanceof File) {
048                return ((File)object).lastModified();
049            } else {
050                Long stamp = (Long)stamps.get(object);
051                if (stamp!=null) {
052                    return stamp.longValue();
053                } else {
054                    return 0;
055                }
056            }
057        }
058    
059        /**
060         * Delete all timestamps
061         */
062        public void touchAll() {
063            Long time = new Long(System.currentTimeMillis());
064            Iterator i = stamps.entrySet().iterator();
065            while (i.hasNext()) {
066                Entry entry = (Entry)i.next();
067                entry.setValue(time);
068            }
069        }
070    }