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.MissingResourceException;
018import java.util.ResourceBundle;
019
020import org.apache.tapestry.engine.IPropertySource;
021
022/**
023 *  A property source that is based on a {@link java.util.ResourceBundle}.
024 *
025 *  @author Howard Lewis Ship
026 *  @since 3.0
027 *
028 **/
029
030public class ResourceBundlePropertySource implements IPropertySource
031{
032    private ResourceBundle _bundle;
033
034    public ResourceBundlePropertySource(ResourceBundle bundle)
035    {
036        _bundle = bundle;
037    }
038
039    /**
040     *  Gets the value from the bundle by invoking
041     *  {@link ResourceBundle#getString(java.lang.String)}.  If
042     *  the bundle does not contain the key (that is, it it
043     *  throws {@link java.util.MissingResourceException}), then
044     *  null is returned.
045     * 
046     **/
047    
048    public String getPropertyValue(String propertyName)
049    {
050        try
051        {
052            return _bundle.getString(propertyName);
053        }
054        catch (MissingResourceException ex)
055        {
056            return null;
057        }
058    }
059
060}