001 /* 002 * Copyright (C) 2011 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017 package com.google.common.net; 018 019 import static com.google.common.base.CharMatcher.ASCII; 020 import static com.google.common.base.CharMatcher.JAVA_ISO_CONTROL; 021 import static com.google.common.base.Charsets.UTF_8; 022 import static com.google.common.base.Preconditions.checkArgument; 023 import static com.google.common.base.Preconditions.checkNotNull; 024 import static com.google.common.base.Preconditions.checkState; 025 026 import com.google.common.annotations.Beta; 027 import com.google.common.annotations.GwtCompatible; 028 import com.google.common.base.Ascii; 029 import com.google.common.base.CharMatcher; 030 import com.google.common.base.Function; 031 import com.google.common.base.Joiner; 032 import com.google.common.base.Joiner.MapJoiner; 033 import com.google.common.base.Objects; 034 import com.google.common.base.Optional; 035 import com.google.common.collect.ImmutableListMultimap; 036 import com.google.common.collect.ImmutableMap; 037 import com.google.common.collect.ImmutableMultiset; 038 import com.google.common.collect.ImmutableSet; 039 import com.google.common.collect.Iterables; 040 import com.google.common.collect.Maps; 041 import com.google.common.collect.Multimap; 042 import com.google.common.collect.Multimaps; 043 044 import java.nio.charset.Charset; 045 import java.nio.charset.IllegalCharsetNameException; 046 import java.nio.charset.UnsupportedCharsetException; 047 import java.util.Collection; 048 import java.util.Map; 049 import java.util.Map.Entry; 050 051 import javax.annotation.Nullable; 052 import javax.annotation.concurrent.Immutable; 053 054 /** 055 * Represents an <a href="http://en.wikipedia.org/wiki/Internet_media_type">Internet Media Type</a> 056 * (also known as a MIME Type or Content Type). This class also supports the concept of media ranges 057 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1">defined by HTTP/1.1</a>. 058 * As such, the {@code *} character is treated as a wildcard and is used to represent any acceptable 059 * type or subtype value. A media type may not have wildcard type with a declared subtype. The 060 * {@code *} character has no special meaning as part of a parameter. All values for type, subtype, 061 * parameter attributes or parameter values must be valid according to RFCs 062 * <a href="http://www.ietf.org/rfc/rfc2045.txt">2045</a> and 063 * <a href="http://www.ietf.org/rfc/rfc2046.txt">2046</a>. 064 * 065 * <p>All portions of the media type that are case-insensitive (type, subtype, parameter attributes) 066 * are normalized to lowercase. The value of the {@code charset} parameter is normalized to 067 * lowercase, but all others are left as-is. 068 * 069 * <p>Note that this specifically does <strong>not</strong> represent the value of the MIME 070 * {@code Content-Type} header and as such has no support for header-specific considerations such as 071 * line folding and comments. 072 * 073 * <p>For media types that take a charset the predefined constants default to UTF-8 and have a 074 * "_UTF_8" suffix. To get a version without a character set, use {@link #withoutParameters}. 075 * 076 * @since 12.0 077 * 078 * @author Gregory Kick 079 */ 080 @Beta 081 @GwtCompatible 082 @Immutable 083 public final class MediaType { 084 private static final String CHARSET_ATTRIBUTE = "charset"; 085 private static final ImmutableListMultimap<String, String> UTF_8_CONSTANT_PARAMETERS = 086 ImmutableListMultimap.of(CHARSET_ATTRIBUTE, Ascii.toLowerCase(UTF_8.name())); 087 088 /** Matcher for type, subtype and attributes. */ 089 private static final CharMatcher TOKEN_MATCHER = ASCII.and(JAVA_ISO_CONTROL.negate()) 090 .and(CharMatcher.isNot(' ')) 091 .and(CharMatcher.noneOf("()<>@,;:\\\"/[]?=")); 092 private static final CharMatcher QUOTED_TEXT_MATCHER = ASCII 093 .and(CharMatcher.noneOf("\"\\\r")); 094 /* 095 * This matches the same characters as linear-white-space from RFC 822, but we make no effort to 096 * enforce any particular rules with regards to line folding as stated in the class docs. 097 */ 098 private static final CharMatcher LINEAR_WHITE_SPACE = CharMatcher.anyOf(" \t\r\n"); 099 100 // TODO(gak): make these public? 101 private static final String APPLICATION_TYPE = "application"; 102 private static final String AUDIO_TYPE = "audio"; 103 private static final String IMAGE_TYPE = "image"; 104 private static final String TEXT_TYPE = "text"; 105 private static final String VIDEO_TYPE = "video"; 106 107 private static final String WILDCARD = "*"; 108 109 /* 110 * The following constants are grouped by their type and ordered alphabetically by the constant 111 * name within that type. The constant name should be a sensible identifier that is closest to the 112 * "common name" of the media. This is often, but not necessarily the same as the subtype. 113 * 114 * Be sure to declare all constants with the type and subtype in all lowercase. 115 * 116 * When adding constants, be sure to add an entry into the KNOWN_TYPES map. For types that 117 * take a charset (e.g. all text/* types), default to UTF-8 and suffix with "_UTF_8". 118 */ 119 120 public static final MediaType ANY_TYPE = createConstant(WILDCARD, WILDCARD); 121 public static final MediaType ANY_TEXT_TYPE = createConstant(TEXT_TYPE, WILDCARD); 122 public static final MediaType ANY_IMAGE_TYPE = createConstant(IMAGE_TYPE, WILDCARD); 123 public static final MediaType ANY_AUDIO_TYPE = createConstant(AUDIO_TYPE, WILDCARD); 124 public static final MediaType ANY_VIDEO_TYPE = createConstant(VIDEO_TYPE, WILDCARD); 125 public static final MediaType ANY_APPLICATION_TYPE = createConstant(APPLICATION_TYPE, WILDCARD); 126 127 /* text types */ 128 public static final MediaType CACHE_MANIFEST_UTF_8 = 129 createConstantUtf8(TEXT_TYPE, "cache-manifest"); 130 public static final MediaType CSS_UTF_8 = createConstantUtf8(TEXT_TYPE, "css"); 131 public static final MediaType CSV_UTF_8 = createConstantUtf8(TEXT_TYPE, "csv"); 132 public static final MediaType HTML_UTF_8 = createConstantUtf8(TEXT_TYPE, "html"); 133 public static final MediaType I_CALENDAR_UTF_8 = createConstantUtf8(TEXT_TYPE, "calendar"); 134 public static final MediaType PLAIN_TEXT_UTF_8 = createConstantUtf8(TEXT_TYPE, "plain"); 135 /** 136 * <a href="http://www.rfc-editor.org/rfc/rfc4329.txt">RFC 4329</a> declares 137 * {@link #JAVASCRIPT_UTF_8 application/javascript} to be the correct media type for JavaScript, 138 * but this may be necessary in certain situations for compatibility. 139 */ 140 public static final MediaType TEXT_JAVASCRIPT_UTF_8 = createConstantUtf8(TEXT_TYPE, "javascript"); 141 public static final MediaType VCARD_UTF_8 = createConstantUtf8(TEXT_TYPE, "vcard"); 142 public static final MediaType XML_UTF_8 = createConstantUtf8(TEXT_TYPE, "xml"); 143 144 /* image types */ 145 public static final MediaType GIF = createConstant(IMAGE_TYPE, "gif"); 146 public static final MediaType ICO = createConstant(IMAGE_TYPE, "vnd.microsoft.icon"); 147 public static final MediaType JPEG = createConstant(IMAGE_TYPE, "jpeg"); 148 public static final MediaType PNG = createConstant(IMAGE_TYPE, "png"); 149 public static final MediaType SVG_UTF_8 = createConstantUtf8(IMAGE_TYPE, "svg+xml"); 150 public static final MediaType TIFF = createConstant(IMAGE_TYPE, "tiff"); 151 152 /* audio types */ 153 public static final MediaType MP4_AUDIO = createConstant(AUDIO_TYPE, "mp4"); 154 public static final MediaType MPEG_AUDIO = createConstant(AUDIO_TYPE, "mpeg"); 155 public static final MediaType OGG_AUDIO = createConstant(AUDIO_TYPE, "ogg"); 156 public static final MediaType WEBM_AUDIO = createConstant(AUDIO_TYPE, "webm"); 157 158 /* video types */ 159 public static final MediaType MP4_VIDEO = createConstant(VIDEO_TYPE, "mp4"); 160 public static final MediaType MPEG_VIDEO = createConstant(VIDEO_TYPE, "mpeg"); 161 public static final MediaType OGG_VIDEO = createConstant(VIDEO_TYPE, "ogg"); 162 public static final MediaType QUICKTIME = createConstant(VIDEO_TYPE, "quicktime"); 163 public static final MediaType WEBM_VIDEO = createConstant(VIDEO_TYPE, "webm"); 164 public static final MediaType WMV = createConstant(VIDEO_TYPE, "x-ms-wmv"); 165 166 /* application types */ 167 public static final MediaType ATOM_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "atom+xml"); 168 public static final MediaType BZIP2 = createConstant(APPLICATION_TYPE, "x-bzip2"); 169 public static final MediaType FORM_DATA = createConstant(APPLICATION_TYPE, 170 "x-www-form-urlencoded"); 171 public static final MediaType GZIP = createConstant(APPLICATION_TYPE, "x-gzip"); 172 /** 173 * <a href="http://www.rfc-editor.org/rfc/rfc4329.txt">RFC 4329</a> declares this to be the 174 * correct media type for JavaScript, but {@link #TEXT_JAVASCRIPT_UTF_8 text/javascript} may be 175 * necessary in certain situations for compatibility. 176 */ 177 public static final MediaType JAVASCRIPT_UTF_8 = 178 createConstantUtf8(APPLICATION_TYPE, "javascript"); 179 public static final MediaType JSON_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "json"); 180 public static final MediaType KML = createConstant(APPLICATION_TYPE, "vnd.google-earth.kml+xml"); 181 public static final MediaType KMZ = createConstant(APPLICATION_TYPE, "vnd.google-earth.kmz"); 182 public static final MediaType MICROSOFT_EXCEL = createConstant(APPLICATION_TYPE, "vnd.ms-excel"); 183 public static final MediaType MICROSOFT_POWERPOINT = 184 createConstant(APPLICATION_TYPE, "vnd.ms-powerpoint"); 185 public static final MediaType MICROSOFT_WORD = createConstant(APPLICATION_TYPE, "msword"); 186 public static final MediaType OCTET_STREAM = createConstant(APPLICATION_TYPE, "octet-stream"); 187 public static final MediaType OGG_CONTAINER = createConstant(APPLICATION_TYPE, "ogg"); 188 public static final MediaType OOXML_DOCUMENT = createConstant(APPLICATION_TYPE, 189 "vnd.openxmlformats-officedocument.wordprocessingml.document"); 190 public static final MediaType OOXML_PRESENTATION = createConstant(APPLICATION_TYPE, 191 "vnd.openxmlformats-officedocument.presentationml.presentation"); 192 public static final MediaType OOXML_SHEET = 193 createConstant(APPLICATION_TYPE, "vnd.openxmlformats-officedocument.spreadsheetml.sheet"); 194 public static final MediaType OPENDOCUMENT_GRAPHICS = 195 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.graphics"); 196 public static final MediaType OPENDOCUMENT_PRESENTATION = 197 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.presentation"); 198 public static final MediaType OPENDOCUMENT_SPREADSHEET = 199 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.spreadsheet"); 200 public static final MediaType OPENDOCUMENT_TEXT = 201 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.text"); 202 public static final MediaType PDF = createConstant(APPLICATION_TYPE, "pdf"); 203 public static final MediaType POSTSCRIPT = createConstant(APPLICATION_TYPE, "postscript"); 204 public static final MediaType RTF_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "rtf"); 205 public static final MediaType SHOCKWAVE_FLASH = createConstant(APPLICATION_TYPE, 206 "x-shockwave-flash"); 207 public static final MediaType TAR = createConstant(APPLICATION_TYPE, "x-tar"); 208 public static final MediaType XHTML_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "xhtml+xml"); 209 public static final MediaType ZIP = createConstant(APPLICATION_TYPE, "zip"); 210 211 private static final ImmutableMap<MediaType, MediaType> KNOWN_TYPES = 212 new ImmutableMap.Builder<MediaType, MediaType>() 213 .put(ANY_TYPE, ANY_TYPE) 214 .put(ANY_TEXT_TYPE, ANY_TEXT_TYPE) 215 .put(ANY_IMAGE_TYPE, ANY_IMAGE_TYPE) 216 .put(ANY_AUDIO_TYPE, ANY_AUDIO_TYPE) 217 .put(ANY_VIDEO_TYPE, ANY_VIDEO_TYPE) 218 .put(ANY_APPLICATION_TYPE, ANY_APPLICATION_TYPE) 219 /* text types */ 220 .put(CACHE_MANIFEST_UTF_8, CACHE_MANIFEST_UTF_8) 221 .put(CSS_UTF_8, CSS_UTF_8) 222 .put(CSV_UTF_8, CSV_UTF_8) 223 .put(HTML_UTF_8, HTML_UTF_8) 224 .put(I_CALENDAR_UTF_8, I_CALENDAR_UTF_8) 225 .put(PLAIN_TEXT_UTF_8, PLAIN_TEXT_UTF_8) 226 .put(TEXT_JAVASCRIPT_UTF_8, TEXT_JAVASCRIPT_UTF_8) 227 .put(VCARD_UTF_8, VCARD_UTF_8) 228 .put(XML_UTF_8, XML_UTF_8) 229 /* image types */ 230 .put(GIF, GIF) 231 .put(ICO, ICO) 232 .put(JPEG, JPEG) 233 .put(PNG, PNG) 234 .put(SVG_UTF_8, SVG_UTF_8) 235 .put(TIFF, TIFF) 236 /* audio types */ 237 .put(MP4_AUDIO, MP4_AUDIO) 238 .put(MPEG_AUDIO, MPEG_AUDIO) 239 .put(OGG_AUDIO, OGG_AUDIO) 240 .put(WEBM_AUDIO, WEBM_AUDIO) 241 /* video types */ 242 .put(MP4_VIDEO, MP4_VIDEO) 243 .put(MPEG_VIDEO, MPEG_VIDEO) 244 .put(OGG_VIDEO, OGG_VIDEO) 245 .put(QUICKTIME, QUICKTIME) 246 .put(WEBM_VIDEO, WEBM_VIDEO) 247 .put(WMV, WMV) 248 /* application types */ 249 .put(ATOM_UTF_8, ATOM_UTF_8) 250 .put(BZIP2, BZIP2) 251 .put(FORM_DATA, FORM_DATA) 252 .put(GZIP, GZIP) 253 .put(JAVASCRIPT_UTF_8, JAVASCRIPT_UTF_8) 254 .put(JSON_UTF_8, JSON_UTF_8) 255 .put(KML, KML) 256 .put(KMZ, KMZ) 257 .put(MICROSOFT_EXCEL, MICROSOFT_EXCEL) 258 .put(MICROSOFT_POWERPOINT, MICROSOFT_POWERPOINT) 259 .put(MICROSOFT_WORD, MICROSOFT_WORD) 260 .put(OCTET_STREAM, OCTET_STREAM) 261 .put(OGG_CONTAINER, OGG_CONTAINER) 262 .put(OOXML_DOCUMENT, OOXML_DOCUMENT) 263 .put(OOXML_PRESENTATION, OOXML_PRESENTATION) 264 .put(OOXML_SHEET, OOXML_SHEET) 265 .put(OPENDOCUMENT_GRAPHICS, OPENDOCUMENT_GRAPHICS) 266 .put(OPENDOCUMENT_PRESENTATION, OPENDOCUMENT_PRESENTATION) 267 .put(OPENDOCUMENT_SPREADSHEET, OPENDOCUMENT_SPREADSHEET) 268 .put(OPENDOCUMENT_TEXT, OPENDOCUMENT_TEXT) 269 .put(PDF, PDF) 270 .put(POSTSCRIPT, POSTSCRIPT) 271 .put(RTF_UTF_8, RTF_UTF_8) 272 .put(SHOCKWAVE_FLASH, SHOCKWAVE_FLASH) 273 .put(TAR, TAR) 274 .put(XHTML_UTF_8, XHTML_UTF_8) 275 .put(ZIP, ZIP) 276 .build(); 277 278 private final String type; 279 private final String subtype; 280 private final ImmutableListMultimap<String, String> parameters; 281 282 private MediaType(String type, String subtype, 283 ImmutableListMultimap<String, String> parameters) { 284 this.type = type; 285 this.subtype = subtype; 286 this.parameters = parameters; 287 } 288 289 private static MediaType createConstant(String type, String subtype) { 290 return new MediaType(type, subtype, ImmutableListMultimap.<String, String>of()); 291 } 292 293 private static MediaType createConstantUtf8(String type, String subtype) { 294 return new MediaType(type, subtype, UTF_8_CONSTANT_PARAMETERS); 295 } 296 297 /** Returns the top-level media type. For example, {@code "text"} in {@code "text/plain"}. */ 298 public String type() { 299 return type; 300 } 301 302 /** Returns the media subtype. For example, {@code "plain"} in {@code "text/plain"}. */ 303 public String subtype() { 304 return subtype; 305 } 306 307 /** Returns a multimap containing the parameters of this media type. */ 308 public ImmutableListMultimap<String, String> parameters() { 309 return parameters; 310 } 311 312 private Map<String, ImmutableMultiset<String>> parametersAsMap() { 313 return Maps.transformValues(parameters.asMap(), 314 new Function<Collection<String>, ImmutableMultiset<String>>() { 315 @Override public ImmutableMultiset<String> apply(Collection<String> input) { 316 return ImmutableMultiset.copyOf(input); 317 } 318 }); 319 } 320 321 /** 322 * Returns an optional charset for the value of the charset parameter if it is specified. 323 * 324 * @throws IllegalStateException if multiple charset values have been set for this media type 325 * @throws IllegalCharsetNameException if a charset value is present, but illegal 326 * @throws UnsupportedCharsetException if a charset value is present, but no support is available 327 * in this instance of the Java virtual machine 328 */ 329 public Optional<Charset> charset() { 330 ImmutableSet<String> charsetValues = ImmutableSet.copyOf(parameters.get(CHARSET_ATTRIBUTE)); 331 switch (charsetValues.size()) { 332 case 0: 333 return Optional.absent(); 334 case 1: 335 return Optional.of(Charset.forName(Iterables.getOnlyElement(charsetValues))); 336 default: 337 throw new IllegalStateException("Multiple charset values defined: " + charsetValues); 338 } 339 } 340 341 /** 342 * Returns a new instance with the same type and subtype as this instance, but without any 343 * parameters. 344 */ 345 public MediaType withoutParameters() { 346 return parameters.isEmpty() ? this : create(type, subtype); 347 } 348 349 /** 350 * <em>Replaces</em> all parameters with the given parameters. 351 * 352 * @throws IllegalArgumentException if any parameter or value is invalid 353 */ 354 public MediaType withParameters(Multimap<String, String> parameters) { 355 return create(type, subtype, parameters); 356 } 357 358 /** 359 * <em>Replaces</em> all parameters with the given attribute with a single parameter with the 360 * given value. If multiple parameters with the same attributes are necessary use 361 * {@link #withParameters}. Prefer {@link #withCharset} for setting the {@code charset} parameter 362 * when using a {@link Charset} object. 363 * 364 * @throws IllegalArgumentException if either {@code attribute} or {@code value} is invalid 365 */ 366 public MediaType withParameter(String attribute, String value) { 367 checkNotNull(attribute); 368 checkNotNull(value); 369 String normalizedAttribute = normalizeToken(attribute); 370 ImmutableListMultimap.Builder<String, String> builder = ImmutableListMultimap.builder(); 371 for (Entry<String, String> entry : parameters.entries()) { 372 String key = entry.getKey(); 373 if (!normalizedAttribute.equals(key)) { 374 builder.put(key, entry.getValue()); 375 } 376 } 377 builder.put(normalizedAttribute, normalizeParameterValue(normalizedAttribute, value)); 378 MediaType mediaType = new MediaType(type, subtype, builder.build()); 379 // Return one of the constants if the media type is a known type. 380 return Objects.firstNonNull(KNOWN_TYPES.get(mediaType), mediaType); 381 } 382 383 /** 384 * Returns a new instance with the same type and subtype as this instance, with the 385 * {@code charset} parameter set to the {@link Charset#name name} of the given charset. Only one 386 * {@code charset} parameter will be present on the new instance regardless of the number set on 387 * this one. 388 * 389 * <p>If a charset must be specified that is not supported on this JVM (and thus is not 390 * representable as a {@link Charset} instance, use {@link #withParameter}. 391 */ 392 public MediaType withCharset(Charset charset) { 393 checkNotNull(charset); 394 return withParameter(CHARSET_ATTRIBUTE, charset.name()); 395 } 396 397 /** Returns true if either the type or subtype is the wildcard. */ 398 public boolean hasWildcard() { 399 return WILDCARD.equals(type) || WILDCARD.equals(subtype); 400 } 401 402 /** 403 * Returns {@code true} if this instance falls within the range (as defined by 404 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html">the HTTP Accept header</a>) 405 * given by the argument according to three criteria: 406 * 407 * <ol> 408 * <li>The type of the argument is the wildcard or equal to the type of this instance. 409 * <li>The subtype of the argument is the wildcard or equal to the subtype of this instance. 410 * <li>All of the parameters present in the argument are present in this instance. 411 * </ol> 412 * 413 * For example: <pre> {@code 414 * PLAIN_TEXT_UTF_8.is(PLAIN_TEXT_UTF_8) // true 415 * PLAIN_TEXT_UTF_8.is(HTML_UTF_8) // false 416 * PLAIN_TEXT_UTF_8.is(ANY_TYPE) // true 417 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE) // true 418 * PLAIN_TEXT_UTF_8.is(ANY_IMAGE_TYPE) // false 419 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE.withCharset(UTF_8)) // true 420 * PLAIN_TEXT_UTF_8.withoutParameters().is(ANY_TEXT_TYPE.withCharset(UTF_8)) // false 421 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE.withCharset(UTF_16)) // false}</pre> 422 * 423 * <p>Note that while it is possible to have the same parameter declared multiple times within a 424 * media type this method does not consider the number of occurrences of a parameter. For 425 * example, {@code "text/plain; charset=UTF-8"} satisfies 426 * {@code "text/plain; charset=UTF-8; charset=UTF-8"}. 427 */ 428 public boolean is(MediaType mediaTypeRange) { 429 return (mediaTypeRange.type.equals(WILDCARD) || mediaTypeRange.type.equals(this.type)) 430 && (mediaTypeRange.subtype.equals(WILDCARD) || mediaTypeRange.subtype.equals(this.subtype)) 431 && this.parameters.entries().containsAll(mediaTypeRange.parameters.entries()); 432 } 433 434 /** 435 * Creates a new media type with the given type and subtype. 436 * 437 * @throws IllegalArgumentException if type or subtype is invalid or if a wildcard is used for the 438 * type, but not the subtype. 439 */ 440 public static MediaType create(String type, String subtype) { 441 return create(type, subtype, ImmutableListMultimap.<String, String>of()); 442 } 443 444 /** 445 * Creates a media type with the "application" type and the given subtype. 446 * 447 * @throws IllegalArgumentException if subtype is invalid 448 */ 449 static MediaType createApplicationType(String subtype) { 450 return create(APPLICATION_TYPE, subtype); 451 } 452 453 /** 454 * Creates a media type with the "audio" type and the given subtype. 455 * 456 * @throws IllegalArgumentException if subtype is invalid 457 */ 458 static MediaType createAudioType(String subtype) { 459 return create(AUDIO_TYPE, subtype); 460 } 461 462 /** 463 * Creates a media type with the "image" type and the given subtype. 464 * 465 * @throws IllegalArgumentException if subtype is invalid 466 */ 467 static MediaType createImageType(String subtype) { 468 return create(IMAGE_TYPE, subtype); 469 } 470 471 /** 472 * Creates a media type with the "text" type and the given subtype. 473 * 474 * @throws IllegalArgumentException if subtype is invalid 475 */ 476 static MediaType createTextType(String subtype) { 477 return create(TEXT_TYPE, subtype); 478 } 479 480 /** 481 * Creates a media type with the "video" type and the given subtype. 482 * 483 * @throws IllegalArgumentException if subtype is invalid 484 */ 485 static MediaType createVideoType(String subtype) { 486 return create(VIDEO_TYPE, subtype); 487 } 488 489 private static MediaType create(String type, String subtype, 490 Multimap<String, String> parameters) { 491 checkNotNull(type); 492 checkNotNull(subtype); 493 checkNotNull(parameters); 494 String normalizedType = normalizeToken(type); 495 String normalizedSubtype = normalizeToken(subtype); 496 checkArgument(!WILDCARD.equals(normalizedType) || WILDCARD.equals(normalizedSubtype), 497 "A wildcard type cannot be used with a non-wildcard subtype"); 498 ImmutableListMultimap.Builder<String, String> builder = ImmutableListMultimap.builder(); 499 for (Entry<String, String> entry : parameters.entries()) { 500 String attribute = normalizeToken(entry.getKey()); 501 builder.put(attribute, normalizeParameterValue(attribute, entry.getValue())); 502 } 503 MediaType mediaType = new MediaType(normalizedType, normalizedSubtype, builder.build()); 504 // Return one of the constants if the media type is a known type. 505 return Objects.firstNonNull(KNOWN_TYPES.get(mediaType), mediaType); 506 } 507 508 private static String normalizeToken(String token) { 509 checkArgument(TOKEN_MATCHER.matchesAllOf(token)); 510 return Ascii.toLowerCase(token); 511 } 512 513 private static String normalizeParameterValue(String attribute, String value) { 514 return CHARSET_ATTRIBUTE.equals(attribute) ? Ascii.toLowerCase(value) : value; 515 } 516 517 /** 518 * Parses a media type from its string representation. 519 * 520 * @throws IllegalArgumentException if the input is not parsable 521 */ 522 public static MediaType parse(String input) { 523 checkNotNull(input); 524 Tokenizer tokenizer = new Tokenizer(input); 525 try { 526 String type = tokenizer.consumeToken(TOKEN_MATCHER); 527 tokenizer.consumeCharacter('/'); 528 String subtype = tokenizer.consumeToken(TOKEN_MATCHER); 529 ImmutableListMultimap.Builder<String, String> parameters = ImmutableListMultimap.builder(); 530 while (tokenizer.hasMore()) { 531 tokenizer.consumeCharacter(';'); 532 tokenizer.consumeTokenIfPresent(LINEAR_WHITE_SPACE); 533 String attribute = tokenizer.consumeToken(TOKEN_MATCHER); 534 tokenizer.consumeCharacter('='); 535 final String value; 536 if ('"' == tokenizer.previewChar()) { 537 tokenizer.consumeCharacter('"'); 538 StringBuilder valueBuilder = new StringBuilder(); 539 while ('"' != tokenizer.previewChar()) { 540 if ('\\' == tokenizer.previewChar()) { 541 tokenizer.consumeCharacter('\\'); 542 valueBuilder.append(tokenizer.consumeCharacter(ASCII)); 543 } else { 544 valueBuilder.append(tokenizer.consumeToken(QUOTED_TEXT_MATCHER)); 545 } 546 } 547 value = valueBuilder.toString(); 548 tokenizer.consumeCharacter('"'); 549 } else { 550 value = tokenizer.consumeToken(TOKEN_MATCHER); 551 } 552 parameters.put(attribute, value); 553 } 554 return create(type, subtype, parameters.build()); 555 } catch (IllegalStateException e) { 556 throw new IllegalArgumentException(e); 557 } 558 } 559 560 private static final class Tokenizer { 561 final String input; 562 int position = 0; 563 564 Tokenizer(String input) { 565 this.input = input; 566 } 567 568 String consumeTokenIfPresent(CharMatcher matcher) { 569 checkState(hasMore()); 570 int startPosition = position; 571 position = matcher.negate().indexIn(input, startPosition); 572 return hasMore() ? input.substring(startPosition, position) : input.substring(startPosition); 573 } 574 575 String consumeToken(CharMatcher matcher) { 576 int startPosition = position; 577 String token = consumeTokenIfPresent(matcher); 578 checkState(position != startPosition); 579 return token; 580 } 581 582 char consumeCharacter(CharMatcher matcher) { 583 checkState(hasMore()); 584 char c = previewChar(); 585 checkState(matcher.matches(c)); 586 position++; 587 return c; 588 } 589 590 char consumeCharacter(char c) { 591 checkState(hasMore()); 592 checkState(previewChar() == c); 593 position++; 594 return c; 595 } 596 597 char previewChar() { 598 checkState(hasMore()); 599 return input.charAt(position); 600 } 601 602 boolean hasMore() { 603 return (position >= 0) && (position < input.length()); 604 } 605 } 606 607 @Override public boolean equals(@Nullable Object obj) { 608 if (obj == this) { 609 return true; 610 } else if (obj instanceof MediaType) { 611 MediaType that = (MediaType) obj; 612 return this.type.equals(that.type) 613 && this.subtype.equals(that.subtype) 614 // compare parameters regardless of order 615 && this.parametersAsMap().equals(that.parametersAsMap()); 616 } else { 617 return false; 618 } 619 } 620 621 @Override public int hashCode() { 622 return Objects.hashCode(type, subtype, parametersAsMap()); 623 } 624 625 private static final MapJoiner PARAMETER_JOINER = Joiner.on("; ").withKeyValueSeparator("="); 626 627 /** 628 * Returns the string representation of this media type in the format described in <a 629 * href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>. 630 */ 631 @Override public String toString() { 632 StringBuilder builder = new StringBuilder().append(type).append('/').append(subtype); 633 if (!parameters.isEmpty()) { 634 builder.append("; "); 635 Multimap<String, String> quotedParameters = Multimaps.transformValues(parameters, 636 new Function<String, String>() { 637 @Override public String apply(String value) { 638 return TOKEN_MATCHER.matchesAllOf(value) ? value : escapeAndQuote(value); 639 } 640 }); 641 PARAMETER_JOINER.appendTo(builder, quotedParameters.entries()); 642 } 643 return builder.toString(); 644 } 645 646 private static String escapeAndQuote(String value) { 647 StringBuilder escaped = new StringBuilder(value.length() + 16).append('"'); 648 for (char ch : value.toCharArray()) { 649 if (ch == '\r' || ch == '\\' || ch == '"') { 650 escaped.append('\\'); 651 } 652 escaped.append(ch); 653 } 654 return escaped.append('"').toString(); 655 } 656 657 }