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 */
020package org.apache.directory.api.ldap.model.schema.comparators;
021
022
023import java.io.Serializable;
024import java.util.Comparator;
025
026import org.apache.directory.api.i18n.I18n;
027import org.apache.directory.api.ldap.model.exception.LdapException;
028import org.apache.directory.api.ldap.model.schema.LdapComparator;
029import org.apache.directory.api.ldap.model.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 * @param <E> The type of object to compare
038 *
039 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
040 */
041public class SerializableComparator<E> extends LdapComparator<E> implements Serializable
042{
043    /** The serial version UID */
044    private static final long serialVersionUID = 2L;
045
046    /** the OID of the matchingRule for this comparator */
047    private String matchingRuleOid;
048
049    /** the transient wrapped comparator */
050    private transient Comparator<E> wrapped;
051
052    /** A reference to the schema manager */
053    private transient SchemaManager schemaManager;
054
055
056    /**
057     * Creates a new instance of SerializableComparator.
058     *
059     * @param matchingRuleOid The MatchingRule OID
060     */
061    public SerializableComparator( String matchingRuleOid )
062    {
063        super( matchingRuleOid );
064        this.matchingRuleOid = matchingRuleOid;
065    }
066
067
068    // ------------------------------------------------------------------------
069    // 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
070    // ------------------------------------------------------------------------
071
072    /**
073     * {@inheritDoc}
074     */
075    @SuppressWarnings("unchecked")
076    @Override
077    public int compare( E o1, E o2 )
078    {
079        if ( wrapped == null )
080        {
081            try
082            {
083                wrapped = ( Comparator<E> ) schemaManager.lookupComparatorRegistry( matchingRuleOid );
084            }
085            catch ( LdapException le )
086            {
087                throw new RuntimeException( I18n.err( I18n.ERR_04221, matchingRuleOid ), le );
088            }
089        }
090
091        return wrapped.compare( o1, o2 );
092    }
093
094
095    /**
096     * @param schemaManager the schemaManager to set
097     */
098    @SuppressWarnings("unchecked")
099    @Override
100    public void setSchemaManager( SchemaManager schemaManager )
101    {
102        if ( wrapped == null )
103        {
104            try
105            {
106                wrapped = ( Comparator<E> )
107                    schemaManager.lookupComparatorRegistry( matchingRuleOid );
108            }
109            catch ( LdapException ne )
110            {
111                // Not found : get the default comparator
112                wrapped = ( Comparator<E> )
113                    new ComparableComparator<>( matchingRuleOid );
114            }
115        }
116
117        ( ( LdapComparator<E> ) wrapped ).setSchemaManager( schemaManager );
118        this.schemaManager = schemaManager;
119    }
120}