001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.common.i18n;
023    
024    import java.net.URL;
025    import java.util.Locale;
026    
027    /**
028     * Implementation of a {@link LocalizationRepository} that loads a properties file from the classpath of the supplied
029     * {@link ClassLoader class loader}.
030     * <p>
031     * This repository for a property file by building locations of the form "path/to/class_locale.properties", where "path/to/class"
032     * is created from the fully-qualified classname and all "." replaced with "/" characters, "locale" is the a variant of the locale
033     * (first the full locale, then subsequently with the last segment removed). As soon as a property file is found, its URL is
034     * returned immediately.
035     * </p>
036     * named with a name that matches
037     * @author Randall Hauch
038     */
039    public class ClasspathLocalizationRepository implements LocalizationRepository {
040    
041        private final ClassLoader classLoader;
042    
043        /**
044         * Create a repository using the current thread's {@link Thread#getContextClassLoader() context class loader} or, if that is
045         * null, the same class loader that loaded this class.
046         */
047        public ClasspathLocalizationRepository() {
048            this(null);
049        }
050    
051        /**
052         * Create a repository using the supplied class loader. Null may be passed if the class loader should be obtained from the
053         * current thread's {@link Thread#getContextClassLoader() context class loader} or, if that is null, the same class loader
054         * that loaded this class.
055         * @param classLoader the class loader to use; may be null
056         */
057        public ClasspathLocalizationRepository( ClassLoader classLoader ) {
058            if (classLoader == null) classLoader = Thread.currentThread().getContextClassLoader();
059            if (classLoader == null) classLoader = this.getClass().getClassLoader();
060            this.classLoader = classLoader;
061        }
062    
063        /**
064         * {@inheritDoc}
065         */
066        public URL getLocalizationBundle( String bundleName, Locale locale ) {
067            URL url = null;
068            String pathPfx = bundleName.replaceAll("\\.", "/");
069            String variant = '_' + locale.toString();
070            do {
071                url = this.classLoader.getResource(pathPfx + variant + ".properties");
072                if (url == null) {
073                    int ndx = variant.lastIndexOf('_');
074                    if (ndx < 0) {
075                        break;
076                    }
077                    variant = variant.substring(0, ndx);
078                }
079            } while (url == null);
080            return url;
081        }
082    
083    }