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.shared.ldap.model.schema.comparators;
021
022
023import java.io.Serializable;
024import java.util.Comparator;
025
026import org.apache.directory.shared.i18n.I18n;
027import org.apache.directory.shared.ldap.model.exception.LdapException;
028import org.apache.directory.shared.ldap.model.schema.LdapComparator;
029import org.apache.directory.shared.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 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
038 */
039public class SerializableComparator<E> extends LdapComparator<E> implements Serializable
040{
041    /** The serial version UID */
042    private static final long serialVersionUID = 2L;
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 ( LdapException 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    @SuppressWarnings("unchecked")
093    public void setSchemaManager( SchemaManager schemaManager )
094    {
095        if ( wrapped == null )
096        {
097            try
098            {
099                wrapped = ( Comparator<E> ) 
100                    schemaManager.lookupComparatorRegistry( matchingRuleOid );
101            }
102            catch ( LdapException ne )
103            {
104                // Not found : get the default comparator
105                wrapped = ( Comparator<E> ) 
106                    new ComparableComparator<Comparable<E>>( matchingRuleOid );
107            }
108        }
109
110        ((LdapComparator<E>)wrapped).setSchemaManager( schemaManager );
111        super.setSchemaManager( schemaManager );
112    }
113}