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.io.Serializable;
024    import java.util.Comparator;
025    
026    
027    /**
028     * A comparator for the objectIdentifierMatch matchingRule.
029     * 
030     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
031     * @version $Rev: 736232 $
032     */
033    public class ObjectIdentifierComparator implements Comparator, Serializable
034    {
035        private static final long serialVersionUID = -2374941241008282707L;
036    
037    
038        public int compare( Object o1, Object o2 )
039        {
040            if ( o1 == null )
041            {
042                return ( o2 == null ) ? 0 : -1;
043            }
044            else if ( o2 == null )
045            {
046                return 1;
047            }
048    
049            if ( o1.equals( o2 ) )
050            {
051                return 0;
052            }
053    
054            if ( !( o1 instanceof String && o2 instanceof String ) )
055            {
056                if ( o1.equals( o2 ) )
057                {
058                    return 0;
059                }
060    
061                return -1;
062            }
063    
064            String s1 = ( ( String ) o1 ).trim().toLowerCase(), s2 = ( ( String ) o2 ).trim().toLowerCase();
065            return s1.compareTo( s2 );
066        }
067    }