001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.codec.language.bm; 019 020import java.io.InputStream; 021import java.util.Collections; 022import java.util.EnumMap; 023import java.util.HashSet; 024import java.util.Map; 025import java.util.NoSuchElementException; 026import java.util.Scanner; 027import java.util.Set; 028 029/** 030 * Language codes. 031 * <p> 032 * Language codes are typically loaded from resource files. These are UTF-8 encoded text files. They are 033 * systematically named following the pattern: 034 * <blockquote>org/apache/commons/codec/language/bm/${{@link NameType#getName()} languages.txt</blockquote> 035 * <p> 036 * The format of these resources is the following: 037 * <ul> 038 * <li><b>Language:</b> a single string containing no whitespace</li> 039 * <li><b>End-of-line comments:</b> Any occurrence of '//' will cause all text following on that line to be 040 * discarded as a comment.</li> 041 * <li><b>Multi-line comments:</b> Any line starting with '/*' will start multi-line commenting mode. 042 * This will skip all content until a line ending in '*' and '/' is found.</li> 043 * <li><b>Blank lines:</b> All blank lines will be skipped.</li> 044 * </ul> 045 * <p> 046 * Ported from language.php 047 * <p> 048 * This class is immutable and thread-safe. 049 * 050 * @since 1.6 051 * @version $Id$ 052 */ 053public class Languages { 054 // Implementation note: This class is divided into two sections. The first part is a static factory interface that 055 // exposes org/apache/commons/codec/language/bm/%s_languages.txt for %s in NameType.* as a list of supported 056 // languages, and a second part that provides instance methods for accessing this set for supported languages. 057 058 /** 059 * A set of languages. 060 */ 061 public static abstract class LanguageSet { 062 063 public static LanguageSet from(final Set<String> langs) { 064 return langs.isEmpty() ? NO_LANGUAGES : new SomeLanguages(langs); 065 } 066 067 public abstract boolean contains(String language); 068 069 public abstract String getAny(); 070 071 public abstract boolean isEmpty(); 072 073 public abstract boolean isSingleton(); 074 075 public abstract LanguageSet restrictTo(LanguageSet other); 076 077 abstract LanguageSet merge(LanguageSet other); 078 } 079 080 /** 081 * Some languages, explicitly enumerated. 082 */ 083 public static final class SomeLanguages extends LanguageSet { 084 private final Set<String> languages; 085 086 private SomeLanguages(final Set<String> languages) { 087 this.languages = Collections.unmodifiableSet(languages); 088 } 089 090 @Override 091 public boolean contains(final String language) { 092 return this.languages.contains(language); 093 } 094 095 @Override 096 public String getAny() { 097 return this.languages.iterator().next(); 098 } 099 100 public Set<String> getLanguages() { 101 return this.languages; 102 } 103 104 @Override 105 public boolean isEmpty() { 106 return this.languages.isEmpty(); 107 } 108 109 @Override 110 public boolean isSingleton() { 111 return this.languages.size() == 1; 112 } 113 114 @Override 115 public LanguageSet restrictTo(final LanguageSet other) { 116 if (other == NO_LANGUAGES) { 117 return other; 118 } else if (other == ANY_LANGUAGE) { 119 return this; 120 } else { 121 final SomeLanguages sl = (SomeLanguages) other; 122 final Set<String> ls = new HashSet<>(Math.min(languages.size(), sl.languages.size())); 123 for (final String lang : languages) { 124 if (sl.languages.contains(lang)) { 125 ls.add(lang); 126 } 127 } 128 return from(ls); 129 } 130 } 131 132 @Override 133 public LanguageSet merge(final LanguageSet other) { 134 if (other == NO_LANGUAGES) { 135 return this; 136 } else if (other == ANY_LANGUAGE) { 137 return other; 138 } else { 139 final SomeLanguages sl = (SomeLanguages) other; 140 final Set<String> ls = new HashSet<>(languages); 141 for (final String lang : sl.languages) { 142 ls.add(lang); 143 } 144 return from(ls); 145 } 146 } 147 148 @Override 149 public String toString() { 150 return "Languages(" + languages.toString() + ")"; 151 } 152 153 } 154 155 public static final String ANY = "any"; 156 157 private static final Map<NameType, Languages> LANGUAGES = new EnumMap<>(NameType.class); 158 159 static { 160 for (final NameType s : NameType.values()) { 161 LANGUAGES.put(s, getInstance(langResourceName(s))); 162 } 163 } 164 165 public static Languages getInstance(final NameType nameType) { 166 return LANGUAGES.get(nameType); 167 } 168 169 public static Languages getInstance(final String languagesResourceName) { 170 // read languages list 171 final Set<String> ls = new HashSet<>(); 172 final InputStream langIS = Languages.class.getClassLoader().getResourceAsStream(languagesResourceName); 173 174 if (langIS == null) { 175 throw new IllegalArgumentException("Unable to resolve required resource: " + languagesResourceName); 176 } 177 178 try (final Scanner lsScanner = new Scanner(langIS, ResourceConstants.ENCODING)) { 179 boolean inExtendedComment = false; 180 while (lsScanner.hasNextLine()) { 181 final String line = lsScanner.nextLine().trim(); 182 if (inExtendedComment) { 183 if (line.endsWith(ResourceConstants.EXT_CMT_END)) { 184 inExtendedComment = false; 185 } 186 } else { 187 if (line.startsWith(ResourceConstants.EXT_CMT_START)) { 188 inExtendedComment = true; 189 } else if (line.length() > 0) { 190 ls.add(line); 191 } 192 } 193 } 194 } 195 196 return new Languages(Collections.unmodifiableSet(ls)); 197 } 198 199 private static String langResourceName(final NameType nameType) { 200 return String.format("org/apache/commons/codec/language/bm/%s_languages.txt", nameType.getName()); 201 } 202 203 private final Set<String> languages; 204 205 /** 206 * No languages at all. 207 */ 208 public static final LanguageSet NO_LANGUAGES = new LanguageSet() { 209 @Override 210 public boolean contains(final String language) { 211 return false; 212 } 213 214 @Override 215 public String getAny() { 216 throw new NoSuchElementException("Can't fetch any language from the empty language set."); 217 } 218 219 @Override 220 public boolean isEmpty() { 221 return true; 222 } 223 224 @Override 225 public boolean isSingleton() { 226 return false; 227 } 228 229 @Override 230 public LanguageSet restrictTo(final LanguageSet other) { 231 return this; 232 } 233 234 @Override 235 public LanguageSet merge(final LanguageSet other) { 236 return other; 237 } 238 239 @Override 240 public String toString() { 241 return "NO_LANGUAGES"; 242 } 243 }; 244 245 /** 246 * Any/all languages. 247 */ 248 public static final LanguageSet ANY_LANGUAGE = new LanguageSet() { 249 @Override 250 public boolean contains(final String language) { 251 return true; 252 } 253 254 @Override 255 public String getAny() { 256 throw new NoSuchElementException("Can't fetch any language from the any language set."); 257 } 258 259 @Override 260 public boolean isEmpty() { 261 return false; 262 } 263 264 @Override 265 public boolean isSingleton() { 266 return false; 267 } 268 269 @Override 270 public LanguageSet restrictTo(final LanguageSet other) { 271 return other; 272 } 273 274 @Override 275 public LanguageSet merge(final LanguageSet other) { 276 return other; 277 } 278 279 @Override 280 public String toString() { 281 return "ANY_LANGUAGE"; 282 } 283 }; 284 285 private Languages(final Set<String> languages) { 286 this.languages = languages; 287 } 288 289 public Set<String> getLanguages() { 290 return this.languages; 291 } 292}