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
015package org.apache.tapestry.web;
016
017import java.util.ArrayList;
018import java.util.Collections;
019import java.util.Enumeration;
020import java.util.List;
021
022import org.apache.hivemind.util.Defense;
023
024/**
025 * @author Howard M. Lewis Ship
026 * @since 4.0
027 */
028public 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}