001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.web;
016    
017    import java.util.ArrayList;
018    import java.util.Collections;
019    import java.util.Enumeration;
020    import java.util.List;
021    
022    import org.apache.hivemind.util.Defense;
023    
024    /**
025     * @author Howard M. Lewis Ship
026     * @since 4.0
027     */
028    public class WebUtils
029    {
030        /**
031         * Converts an Enumeration of Strings into an unmodifiable List of Strings, sorted into
032         * ascending order.
033         */
034    
035        public static List toSortedList(Enumeration e)
036        {
037            Defense.notNull(e, "e");
038    
039            List list = new ArrayList();
040            while (e.hasMoreElements())
041                list.add(e.nextElement());
042    
043            if (list.isEmpty())
044                return Collections.EMPTY_LIST;
045    
046            Collections.sort(list);
047    
048            return Collections.unmodifiableList(list);
049        }
050    
051    }