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. 014 015 package org.apache.hivemind.impl; 016 017 import java.io.BufferedInputStream; 018 import java.io.IOException; 019 import java.io.InputStream; 020 import java.net.URL; 021 import java.util.ArrayList; 022 import java.util.Collections; 023 import java.util.HashMap; 024 import java.util.Iterator; 025 import java.util.List; 026 import java.util.Locale; 027 import java.util.Map; 028 import java.util.Properties; 029 030 import org.apache.hivemind.ApplicationRuntimeException; 031 import org.apache.hivemind.Resource; 032 import org.apache.hivemind.internal.MessageFinder; 033 import org.apache.hivemind.util.Defense; 034 import org.apache.hivemind.util.IOUtils; 035 import org.apache.hivemind.util.LocalizedNameGenerator; 036 037 /** 038 * @author Howard M. Lewis Ship 039 * @since 1.1 040 */ 041 public class MessageFinderImpl implements MessageFinder 042 { 043 private static final String EXTENSION = ".properties"; 044 045 private static class Localization 046 { 047 private Locale _locale; 048 049 private Resource _resource; 050 051 Localization(Locale locale, Resource resource) 052 { 053 _locale = locale; 054 _resource = resource; 055 } 056 057 public Locale getLocale() 058 { 059 return _locale; 060 } 061 062 public Resource getResource() 063 { 064 return _resource; 065 } 066 067 } 068 069 private Resource _baseResource; 070 071 private String _baseName; 072 073 private Map _propertiesMap = new HashMap(); 074 075 private Properties _emptyProperties = new Properties(); 076 077 public MessageFinderImpl(Resource baseResource) 078 { 079 Defense.notNull(baseResource, "baseResource"); 080 081 _baseResource = baseResource; 082 083 // Strip off the extension to form the base name 084 // when building new (localized) resources. 085 086 String name = _baseResource.getName(); 087 int dotx = name.lastIndexOf('.'); 088 089 _baseName = name.substring(0, dotx); 090 } 091 092 public String getMessage(String key, Locale locale) 093 { 094 return findProperties(locale).getProperty(key); 095 } 096 097 private synchronized Properties findProperties(Locale locale) 098 { 099 Properties result = (Properties) _propertiesMap.get(locale); 100 101 // If doesn't exist, build it (which will update the 102 // propertiesMap as a side effect. 103 104 if (result == null) 105 result = buildProperties(locale); 106 107 return result; 108 } 109 110 private Properties buildProperties(Locale locale) 111 { 112 Properties result = _emptyProperties; 113 114 List localizations = findLocalizations(locale); 115 116 Iterator i = localizations.iterator(); 117 while (i.hasNext()) 118 { 119 Localization l = (Localization) i.next(); 120 121 result = readProperties(l.getLocale(), l.getResource(), result); 122 } 123 124 return result; 125 } 126 127 /** 128 * Returns the properties, reading them if necessary. Properties may have been previously read 129 * for this locale, in which case the cached value is returned. Also, if the resource doesn't 130 * exist, then the parent is returned as is. Updates the propertiesMap cache. 131 */ 132 133 private Properties readProperties(Locale locale, Resource propertiesResource, Properties parent) 134 { 135 Properties result = (Properties) _propertiesMap.get(locale); 136 137 if (result != null) 138 return result; 139 140 URL url = propertiesResource.getResourceURL(); 141 142 if (url == null) 143 result = parent; 144 else 145 result = readPropertiesFile(url, parent); 146 147 _propertiesMap.put(locale, result); 148 149 return result; 150 } 151 152 private Properties readPropertiesFile(URL url, Properties parent) 153 { 154 InputStream stream = null; 155 156 Properties result = new Properties(parent); 157 158 try 159 { 160 stream = new BufferedInputStream(url.openStream()); 161 162 result.load(stream); 163 164 stream.close(); 165 166 stream = null; 167 } 168 catch (IOException ex) 169 { 170 throw new ApplicationRuntimeException(ImplMessages.unableToReadMessages(url), ex); 171 172 } 173 finally 174 { 175 IOUtils.close(stream); 176 } 177 178 return result; 179 } 180 181 /** 182 * Returns a List of Localizations, in order from most generic (i.e., hivemodule.properties) to 183 * most specific (i.e., hivemodule_en_US_yokel.properties). 184 */ 185 186 private List findLocalizations(Locale locale) 187 { 188 List result = new ArrayList(); 189 190 LocalizedNameGenerator g = new LocalizedNameGenerator(_baseName, locale, EXTENSION); 191 192 while (g.more()) 193 { 194 String name = g.next(); 195 196 Localization l = new Localization(g.getCurrentLocale(), _baseResource 197 .getRelativeResource(name)); 198 199 result.add(l); 200 } 201 202 Collections.reverse(result); 203 204 return result; 205 } 206 }