001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.shared.ldap.schema.comparators;
021    
022    
023    import java.util.Comparator;
024    
025    import javax.naming.NamingException;
026    
027    import org.apache.directory.shared.i18n.I18n;
028    import org.apache.directory.shared.ldap.schema.LdapComparator;
029    import org.apache.directory.shared.ldap.schema.SchemaManager;
030    
031    
032    /**
033     * A serializable wrapper around a Comparator which uses delayed initialization
034     * of the underlying wrapped comparator which is JIT resolved from a static
035     * global registry.
036     *
037     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
038     * @version $Rev: 912436 $
039     */
040    public class SerializableComparator<E> extends LdapComparator<E>
041    {
042        private static final long serialVersionUID = 3257566226288162870L;
043    
044        /** the OID of the matchingRule for this comparator */
045        private String matchingRuleOid;
046        
047        /** the transient wrapped comparator */
048        private transient Comparator<E> wrapped;
049    
050        /** A reference to the schema manager */ 
051        private transient SchemaManager schemaManager;
052        
053        // ------------------------------------------------------------------------
054        // C O N T R U C T O R S
055        // ------------------------------------------------------------------------
056        public SerializableComparator( String matchingRuleOid )
057        {
058            super( matchingRuleOid );
059            this.matchingRuleOid = matchingRuleOid;
060        }
061    
062    
063        // ------------------------------------------------------------------------
064        // C O M P A R A T O R   I M P L E M E N T A T I O N S
065        // ------------------------------------------------------------------------
066    
067        /**
068         * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
069         */
070        @SuppressWarnings("unchecked")
071        public int compare( E o1, E o2 )
072        {
073            if ( wrapped == null )
074            {
075                try
076                {
077                    wrapped = (Comparator<E>)schemaManager.lookupComparatorRegistry( matchingRuleOid );
078                }
079                catch ( NamingException e )
080                {
081                    throw new RuntimeException( I18n.err( I18n.ERR_04221, matchingRuleOid ) );
082                }
083            }
084    
085            return wrapped.compare( o1, o2 );
086        }
087    
088    
089        /**
090         * @param schemaManager the schemaManager to set
091         */
092        public void setSchemaManager( SchemaManager schemaManager )
093        {
094            if ( wrapped == null )
095            {
096                try
097                {
098                    wrapped = (Comparator<E>)schemaManager.lookupComparatorRegistry( matchingRuleOid );
099                }
100                catch ( NamingException ne )
101                {
102                    // Not found : get the default comparator
103                    wrapped = (Comparator<E>)new ComparableComparator<Comparable<E>>( matchingRuleOid );
104                }
105            }
106    
107            ((LdapComparator<E>)wrapped).setSchemaManager( schemaManager );
108            super.setSchemaManager( schemaManager );
109        }
110    }