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    package org.apache.wiki.auth;
020    
021    import java.io.Serializable;
022    import java.security.Principal;
023    import java.text.Collator;
024    import java.util.Comparator;
025    
026    /**
027     * Comparator class for sorting objects of type Principal.
028     * Used for sorting arrays or collections of Principals.
029     * @since 2.3
030     */
031    public class PrincipalComparator
032        implements Comparator<Principal>, Serializable
033    {
034        private static final long serialVersionUID = 1L;
035    
036        /**
037         * Compares two Principal objects.
038         * @param o1 the first Principal
039         * @param o2 the second Principal
040         * @return the result of the comparison
041         * @see java.util.Comparator#compare(Object, Object)
042         */
043        public int compare( Principal o1, Principal o2 )
044        {
045            Collator collator = Collator.getInstance();
046            return collator.compare( o1.getName(), o2.getName() );
047        }
048    
049    }