001// Copyright 2006, 2012 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.tapestry5.commons.internal.util;
016
017import java.util.Enumeration;
018import java.util.Locale;
019import java.util.Map;
020import java.util.ResourceBundle;
021import java.util.Set;
022
023import org.apache.tapestry5.commons.Messages;
024import org.apache.tapestry5.commons.util.AbstractMessages;
025import org.apache.tapestry5.commons.util.CollectionFactory;
026
027/**
028 * Implementation of {@link org.apache.tapestry5.commons.Messages} based around a {@link java.util.ResourceBundle}.
029 */
030public class MessagesImpl extends AbstractMessages
031{
032    private final Map<String, String> properties = CollectionFactory.newCaseInsensitiveMap();
033
034    /**
035     * Finds the messages for a given Messages utility class. Strings the trailing "Messages" and replaces it with
036     * "Strings" to form the base path. Loads the bundle using the default locale, and the class' class loader.
037     *
038     * @param forClass
039     * @return Messages for the class
040     */
041    public static Messages forClass(Class forClass)
042    {
043        String className = forClass.getName();
044        String stringsClassName = className.replaceAll("Messages$", "Strings");
045
046        Locale locale = Locale.getDefault();
047
048        ResourceBundle bundle = ResourceBundle.getBundle(stringsClassName, locale, forClass.getClassLoader());
049
050        return new MessagesImpl(locale, bundle);
051    }
052
053    public MessagesImpl(Locale locale, ResourceBundle bundle)
054    {
055        super(locale);
056
057        // Our best (threadsafe) chance to determine all the available keys.
058        Enumeration<String> e = bundle.getKeys();
059        while (e.hasMoreElements())
060        {
061            String key = e.nextElement();
062            String value = bundle.getString(key);
063
064            properties.put(key, value);
065        }
066    }
067
068    @Override
069    protected String valueForKey(String key)
070    {
071        return properties.get(key);
072    }
073
074    @Override
075    public Set<String> getKeys()
076    {
077        return properties.keySet();
078    }
079}