001// Copyright 2004, 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.util;
016
017import java.util.ArrayList;
018import java.util.Collections;
019import java.util.HashMap;
020import java.util.List;
021import java.util.Map;
022
023/**
024 *  Base class implementation for the {@link IPropertyHolder} interface.
025 *
026 *
027 *  @author Howard Lewis Ship
028 *
029 **/
030
031public class BasePropertyHolder implements IPropertyHolder
032{
033    private static final int MAP_SIZE = 7;
034    private Map properties;
035
036    public String getProperty(String name)
037    {
038        if (properties == null)
039            return null;
040
041        return (String) properties.get(name);
042    }
043
044    public void setProperty(String name, String value)
045    {
046        if (value == null)
047        {
048            removeProperty(name);
049            return;
050        }
051
052        if (properties == null)
053            properties = new HashMap(MAP_SIZE);
054
055        properties.put(name, value);
056    }
057
058    public void removeProperty(String name)
059    {
060        if (properties == null)
061            return;
062
063        properties.remove(name);
064    }
065
066    public List getPropertyNames()
067    {
068        if (properties == null)
069            return Collections.EMPTY_LIST;
070
071        List result = new ArrayList(properties.keySet());
072        
073        Collections.sort(result);
074        
075        return result;
076    }
077
078}