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 org.apache.directory.api.i18n.I18n;
024import org.apache.directory.api.ldap.model.exception.LdapException;
025import org.apache.directory.api.ldap.model.exception.LdapInvalidDnException;
026import org.apache.directory.api.ldap.model.name.Dn;
027import org.apache.directory.api.ldap.model.schema.LdapComparator;
028import org.apache.directory.api.ldap.model.schema.SchemaManager;
029
030
031/**
032 * Compare two DNs
033 * 
034 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035 */
036public class DnComparator extends LdapComparator<Object>
037{
038    /** The serial version UID */
039    private static final long serialVersionUID = 2L;
040
041    /** A reference to the schema manager */
042    private SchemaManager schemaManager;
043
044    /**
045     * Creates a new instance of DnComparator.
046     *
047     * @param oid The Comparator's OID
048     */
049    public DnComparator( String oid )
050    {
051        super( oid );
052    }
053
054
055    /**
056     * {@inheritDoc}
057     */
058    @Override
059    public int compare( Object obj0, Object obj1 )
060    {
061        Dn dn0 = null;
062        Dn dn1 = null;
063
064        try
065        {
066            dn0 = getDn( obj0 );
067            dn1 = getDn( obj1 );
068        }
069        catch ( LdapException e )
070        {
071            // -- what do we do here ?
072            return -1;
073        }
074
075        int dn0Size = dn0.getRdns().size();
076        int dn1Size = dn1.getRdns().size();
077        
078        // check the equality first, cause
079        // when both DNs are equal checking isAncestorOf() returns true
080        if ( dn0.equals( dn1 ) )
081        {
082            return 0;
083        }
084        else if ( dn0Size > dn1Size )
085        {
086            return -1;
087        }
088        else if ( dn1Size > dn0Size )
089        {
090            return 1;
091        }
092
093        return dn0.getNormName().compareTo( dn1.getNormName() );
094    }
095
096
097    private Dn getDn( Object obj ) throws LdapInvalidDnException
098    {
099        Dn dn;
100
101        if ( obj instanceof Dn )
102        {
103            dn = ( Dn ) obj;
104
105            dn = dn.isSchemaAware() ? dn : dn.apply( schemaManager );
106        }
107        else if ( obj instanceof String )
108        {
109            dn = new Dn( schemaManager, ( String ) obj );
110        }
111        else
112        {
113            throw new IllegalStateException( I18n.err( I18n.ERR_04218, obj == null ? null : obj.getClass() ) );
114        }
115
116        return dn;
117    }
118
119
120    /**
121     * {@inheritDoc}
122     */
123    @Override
124    public void setSchemaManager( SchemaManager schemaManager )
125    {
126        this.schemaManager = schemaManager;
127    }
128}