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 */
019package org.apache.wiki.auth;
020
021import java.io.Serializable;
022import java.security.Principal;
023import java.text.Collator;
024import 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 */
031public 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}