001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors.
008     *
009     * Unless otherwise indicated, all code in JBoss DNA is licensed
010     * to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     * 
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.jcr;
025    
026    import java.util.UUID;
027    import net.jcip.annotations.Immutable;
028    import org.jboss.dna.common.util.HashCode;
029    import org.jboss.dna.graph.property.Name;
030    
031    /**
032     * An immutable identifier for a property, often used to reference information a property held within the {@link SessionCache}.
033     */
034    @Immutable
035    public final class PropertyId {
036    
037        private final UUID nodeId;
038        private final Name propertyName;
039        private final int hc;
040    
041        /**
042         * Create a new property identifier.
043         * 
044         * @param nodeId the UUID of the node that owns the property being reference; may not be null
045         * @param propertyName the name of the property being referenced; may not be null
046         */
047        public PropertyId( UUID nodeId,
048                           Name propertyName ) {
049            assert nodeId != null;
050            assert propertyName != null;
051            this.nodeId = nodeId;
052            this.propertyName = propertyName;
053            this.hc = HashCode.compute(this.nodeId, this.propertyName);
054        }
055    
056        /**
057         * Get the UUID of the node that owns the property.
058         * 
059         * @return the node's UUID; never null
060         */
061        public UUID getNodeId() {
062            return nodeId;
063        }
064    
065        /**
066         * Get the name of the property.
067         * 
068         * @return the property name; never null
069         */
070        public Name getPropertyName() {
071            return propertyName;
072        }
073    
074        /**
075         * {@inheritDoc}
076         * 
077         * @see java.lang.Object#hashCode()
078         */
079        @Override
080        public int hashCode() {
081            return hc;
082        }
083    
084        /**
085         * {@inheritDoc}
086         * 
087         * @see java.lang.Object#equals(java.lang.Object)
088         */
089        @Override
090        public boolean equals( Object obj ) {
091            if (obj == this) return true;
092            if (obj instanceof PropertyId) {
093                PropertyId that = (PropertyId)obj;
094                if (this.hc != that.hc) return false;
095                if (!this.nodeId.equals(that.nodeId)) return false;
096                return this.propertyName.equals(that.propertyName);
097            }
098            return false;
099        }
100    
101        /**
102         * {@inheritDoc}
103         * 
104         * @see java.lang.Object#toString()
105         */
106        @Override
107        public String toString() {
108            return this.nodeId.toString() + '@' + this.propertyName.toString();
109        }
110    
111    }