001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.graph.cache;
023    
024    import java.io.Serializable;
025    import org.jboss.dna.graph.properties.DateTime;
026    
027    /**
028     * Interface defining an object that can be cached according to a {@link CachePolicy}.
029     * 
030     * @author Randall Hauch
031     */
032    public interface Cacheable extends Serializable {
033    
034        /**
035         * Get the time that this node data was originally loaded.
036         * 
037         * @return the system time (in milliseconds) that the node data was loaded
038         */
039        DateTime getTimeLoaded();
040    
041        /**
042         * Get the caching policy to be used for this object.
043         * <p>
044         * Note that the values of the policy are relative to the {@link #getTimeLoaded() time the node was loaded}, so the same
045         * instance can be used for many nodes.
046         * </p>
047         * 
048         * @return cachePolicy the caching policy, which may not be null
049         */
050        public CachePolicy getCachePolicy();
051    
052        /**
053         * Set the caching policy for this object.
054         * 
055         * @param cachePolicy the caching policy to use for this object
056         * @throws IllegalArgumentException if the cachePolicy is null
057         */
058        public void setCachePolicy( CachePolicy cachePolicy );
059    
060    }