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.connector.federation.contribution;
023    
024    import java.util.Iterator;
025    import net.jcip.annotations.Immutable;
026    import org.jboss.dna.graph.Location;
027    import org.jboss.dna.graph.properties.DateTime;
028    
029    /**
030     * The record of a source contributing only a single child to a node.
031     * 
032     * @author Randall Hauch
033     */
034    @Immutable
035    public class OneChildContribution extends NonEmptyContribution {
036    
037        /**
038         * This is the first version of this class. See the documentation of MergePlan.serialVersionUID.
039         */
040        private static final long serialVersionUID = 1L;
041    
042        private final Location child;
043    
044        /**
045         * Create a contribution of a single child from the source with the supplied name.
046         * 
047         * @param sourceName the name of the source, which may not be null or blank
048         * @param locationInSource the location in the source for this contributed information; may not be null
049         * @param expirationTime the time (in UTC) after which this contribution should be considered expired, or null if there is no
050         *        expiration time
051         * @param child the child contributed from the source; may not be null
052         */
053        public OneChildContribution( String sourceName,
054                                     Location locationInSource,
055                                     DateTime expirationTime,
056                                     Location child ) {
057            super(sourceName, locationInSource, expirationTime);
058            assert child != null;
059            this.child = child;
060            if (ContributionStatistics.RECORD) ContributionStatistics.record(0, 1);
061        }
062    
063        /**
064         * {@inheritDoc}
065         * 
066         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildren()
067         */
068        @Override
069        public Iterator<Location> getChildren() {
070            return new OneValueIterator<Location>(child);
071        }
072    
073        /**
074         * {@inheritDoc}
075         * 
076         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildrenCount()
077         */
078        @Override
079        public int getChildrenCount() {
080            return 1;
081        }
082    
083    }