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 WML_UTF_8 = createConstantUtf8(TEXT_TYPE, "vnd.wap.wml");
143 public static final MediaType XML_UTF_8 = createConstantUtf8(TEXT_TYPE, "xml");
144
145 /* image types */
146 public static final MediaType BMP = createConstant(IMAGE_TYPE, "bmp");
147 public static final MediaType GIF = createConstant(IMAGE_TYPE, "gif");
148 public static final MediaType ICO = createConstant(IMAGE_TYPE, "vnd.microsoft.icon");
149 public static final MediaType JPEG = createConstant(IMAGE_TYPE, "jpeg");
150 public static final MediaType PNG = createConstant(IMAGE_TYPE, "png");
151 public static final MediaType SVG_UTF_8 = createConstantUtf8(IMAGE_TYPE, "svg+xml");
152 public static final MediaType TIFF = createConstant(IMAGE_TYPE, "tiff");
153 public static final MediaType WEBP = createConstant(IMAGE_TYPE, "webp");
154
155 /* audio types */
156 public static final MediaType MP4_AUDIO = createConstant(AUDIO_TYPE, "mp4");
157 public static final MediaType MPEG_AUDIO = createConstant(AUDIO_TYPE, "mpeg");
158 public static final MediaType OGG_AUDIO = createConstant(AUDIO_TYPE, "ogg");
159 public static final MediaType WEBM_AUDIO = createConstant(AUDIO_TYPE, "webm");
160
161 /* video types */
162 public static final MediaType MP4_VIDEO = createConstant(VIDEO_TYPE, "mp4");
163 public static final MediaType MPEG_VIDEO = createConstant(VIDEO_TYPE, "mpeg");
164 public static final MediaType OGG_VIDEO = createConstant(VIDEO_TYPE, "ogg");
165 public static final MediaType QUICKTIME = createConstant(VIDEO_TYPE, "quicktime");
166 public static final MediaType WEBM_VIDEO = createConstant(VIDEO_TYPE, "webm");
167 public static final MediaType WMV = createConstant(VIDEO_TYPE, "x-ms-wmv");
168
169 /* application types */
170 public static final MediaType ATOM_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "atom+xml");
171 public static final MediaType BZIP2 = createConstant(APPLICATION_TYPE, "x-bzip2");
172 public static final MediaType FORM_DATA = createConstant(APPLICATION_TYPE,
173 "x-www-form-urlencoded");
174 public static final MediaType GZIP = createConstant(APPLICATION_TYPE, "x-gzip");
175 /**
176 * <a href="http://www.rfc-editor.org/rfc/rfc4329.txt">RFC 4329</a> declares this to be the
177 * correct media type for JavaScript, but {@link #TEXT_JAVASCRIPT_UTF_8 text/javascript} may be
178 * necessary in certain situations for compatibility.
179 */
180 public static final MediaType JAVASCRIPT_UTF_8 =
181 createConstantUtf8(APPLICATION_TYPE, "javascript");
182 public static final MediaType JSON_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "json");
183 public static final MediaType KML = createConstant(APPLICATION_TYPE, "vnd.google-earth.kml+xml");
184 public static final MediaType KMZ = createConstant(APPLICATION_TYPE, "vnd.google-earth.kmz");
185 public static final MediaType MBOX = createConstant(APPLICATION_TYPE, "mbox");
186 public static final MediaType MICROSOFT_EXCEL = createConstant(APPLICATION_TYPE, "vnd.ms-excel");
187 public static final MediaType MICROSOFT_POWERPOINT =
188 createConstant(APPLICATION_TYPE, "vnd.ms-powerpoint");
189 public static final MediaType MICROSOFT_WORD = createConstant(APPLICATION_TYPE, "msword");
190 public static final MediaType OCTET_STREAM = createConstant(APPLICATION_TYPE, "octet-stream");
191 public static final MediaType OGG_CONTAINER = createConstant(APPLICATION_TYPE, "ogg");
192 public static final MediaType OOXML_DOCUMENT = createConstant(APPLICATION_TYPE,
193 "vnd.openxmlformats-officedocument.wordprocessingml.document");
194 public static final MediaType OOXML_PRESENTATION = createConstant(APPLICATION_TYPE,
195 "vnd.openxmlformats-officedocument.presentationml.presentation");
196 public static final MediaType OOXML_SHEET =
197 createConstant(APPLICATION_TYPE, "vnd.openxmlformats-officedocument.spreadsheetml.sheet");
198 public static final MediaType OPENDOCUMENT_GRAPHICS =
199 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.graphics");
200 public static final MediaType OPENDOCUMENT_PRESENTATION =
201 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.presentation");
202 public static final MediaType OPENDOCUMENT_SPREADSHEET =
203 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.spreadsheet");
204 public static final MediaType OPENDOCUMENT_TEXT =
205 createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.text");
206 public static final MediaType PDF = createConstant(APPLICATION_TYPE, "pdf");
207 public static final MediaType POSTSCRIPT = createConstant(APPLICATION_TYPE, "postscript");
208 public static final MediaType RTF_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "rtf");
209 public static final MediaType SHOCKWAVE_FLASH = createConstant(APPLICATION_TYPE,
210 "x-shockwave-flash");
211 public static final MediaType SKETCHUP = createConstant(APPLICATION_TYPE, "vnd.sketchup.skp");
212 public static final MediaType TAR = createConstant(APPLICATION_TYPE, "x-tar");
213 public static final MediaType XHTML_UTF_8 = createConstantUtf8(APPLICATION_TYPE, "xhtml+xml");
214 public static final MediaType ZIP = createConstant(APPLICATION_TYPE, "zip");
215
216 private static final ImmutableMap<MediaType, MediaType> KNOWN_TYPES =
217 new ImmutableMap.Builder<MediaType, MediaType>()
218 .put(ANY_TYPE, ANY_TYPE)
219 .put(ANY_TEXT_TYPE, ANY_TEXT_TYPE)
220 .put(ANY_IMAGE_TYPE, ANY_IMAGE_TYPE)
221 .put(ANY_AUDIO_TYPE, ANY_AUDIO_TYPE)
222 .put(ANY_VIDEO_TYPE, ANY_VIDEO_TYPE)
223 .put(ANY_APPLICATION_TYPE, ANY_APPLICATION_TYPE)
224 /* text types */
225 .put(CACHE_MANIFEST_UTF_8, CACHE_MANIFEST_UTF_8)
226 .put(CSS_UTF_8, CSS_UTF_8)
227 .put(CSV_UTF_8, CSV_UTF_8)
228 .put(HTML_UTF_8, HTML_UTF_8)
229 .put(I_CALENDAR_UTF_8, I_CALENDAR_UTF_8)
230 .put(PLAIN_TEXT_UTF_8, PLAIN_TEXT_UTF_8)
231 .put(TEXT_JAVASCRIPT_UTF_8, TEXT_JAVASCRIPT_UTF_8)
232 .put(VCARD_UTF_8, VCARD_UTF_8)
233 .put(WML_UTF_8, WML_UTF_8)
234 .put(XML_UTF_8, XML_UTF_8)
235 /* image types */
236 .put(BMP, BMP)
237 .put(GIF, GIF)
238 .put(ICO, ICO)
239 .put(JPEG, JPEG)
240 .put(PNG, PNG)
241 .put(SVG_UTF_8, SVG_UTF_8)
242 .put(TIFF, TIFF)
243 .put(WEBP, WEBP)
244 /* audio types */
245 .put(MP4_AUDIO, MP4_AUDIO)
246 .put(MPEG_AUDIO, MPEG_AUDIO)
247 .put(OGG_AUDIO, OGG_AUDIO)
248 .put(WEBM_AUDIO, WEBM_AUDIO)
249 /* video types */
250 .put(MP4_VIDEO, MP4_VIDEO)
251 .put(MPEG_VIDEO, MPEG_VIDEO)
252 .put(OGG_VIDEO, OGG_VIDEO)
253 .put(QUICKTIME, QUICKTIME)
254 .put(WEBM_VIDEO, WEBM_VIDEO)
255 .put(WMV, WMV)
256 /* application types */
257 .put(ATOM_UTF_8, ATOM_UTF_8)
258 .put(BZIP2, BZIP2)
259 .put(FORM_DATA, FORM_DATA)
260 .put(GZIP, GZIP)
261 .put(JAVASCRIPT_UTF_8, JAVASCRIPT_UTF_8)
262 .put(JSON_UTF_8, JSON_UTF_8)
263 .put(KML, KML)
264 .put(KMZ, KMZ)
265 .put(MBOX, MBOX)
266 .put(MICROSOFT_EXCEL, MICROSOFT_EXCEL)
267 .put(MICROSOFT_POWERPOINT, MICROSOFT_POWERPOINT)
268 .put(MICROSOFT_WORD, MICROSOFT_WORD)
269 .put(OCTET_STREAM, OCTET_STREAM)
270 .put(OGG_CONTAINER, OGG_CONTAINER)
271 .put(OOXML_DOCUMENT, OOXML_DOCUMENT)
272 .put(OOXML_PRESENTATION, OOXML_PRESENTATION)
273 .put(OOXML_SHEET, OOXML_SHEET)
274 .put(OPENDOCUMENT_GRAPHICS, OPENDOCUMENT_GRAPHICS)
275 .put(OPENDOCUMENT_PRESENTATION, OPENDOCUMENT_PRESENTATION)
276 .put(OPENDOCUMENT_SPREADSHEET, OPENDOCUMENT_SPREADSHEET)
277 .put(OPENDOCUMENT_TEXT, OPENDOCUMENT_TEXT)
278 .put(PDF, PDF)
279 .put(POSTSCRIPT, POSTSCRIPT)
280 .put(RTF_UTF_8, RTF_UTF_8)
281 .put(SHOCKWAVE_FLASH, SHOCKWAVE_FLASH)
282 .put(SKETCHUP, SKETCHUP)
283 .put(TAR, TAR)
284 .put(XHTML_UTF_8, XHTML_UTF_8)
285 .put(ZIP, ZIP)
286 .build();
287
288 private final String type;
289 private final String subtype;
290 private final ImmutableListMultimap<String, String> parameters;
291
292 private MediaType(String type, String subtype,
293 ImmutableListMultimap<String, String> parameters) {
294 this.type = type;
295 this.subtype = subtype;
296 this.parameters = parameters;
297 }
298
299 private static MediaType createConstant(String type, String subtype) {
300 return new MediaType(type, subtype, ImmutableListMultimap.<String, String>of());
301 }
302
303 private static MediaType createConstantUtf8(String type, String subtype) {
304 return new MediaType(type, subtype, UTF_8_CONSTANT_PARAMETERS);
305 }
306
307 /** Returns the top-level media type. For example, {@code "text"} in {@code "text/plain"}. */
308 public String type() {
309 return type;
310 }
311
312 /** Returns the media subtype. For example, {@code "plain"} in {@code "text/plain"}. */
313 public String subtype() {
314 return subtype;
315 }
316
317 /** Returns a multimap containing the parameters of this media type. */
318 public ImmutableListMultimap<String, String> parameters() {
319 return parameters;
320 }
321
322 private Map<String, ImmutableMultiset<String>> parametersAsMap() {
323 return Maps.transformValues(parameters.asMap(),
324 new Function<Collection<String>, ImmutableMultiset<String>>() {
325 @Override public ImmutableMultiset<String> apply(Collection<String> input) {
326 return ImmutableMultiset.copyOf(input);
327 }
328 });
329 }
330
331 /**
332 * Returns an optional charset for the value of the charset parameter if it is specified.
333 *
334 * @throws IllegalStateException if multiple charset values have been set for this media type
335 * @throws IllegalCharsetNameException if a charset value is present, but illegal
336 * @throws UnsupportedCharsetException if a charset value is present, but no support is available
337 * in this instance of the Java virtual machine
338 */
339 public Optional<Charset> charset() {
340 ImmutableSet<String> charsetValues = ImmutableSet.copyOf(parameters.get(CHARSET_ATTRIBUTE));
341 switch (charsetValues.size()) {
342 case 0:
343 return Optional.absent();
344 case 1:
345 return Optional.of(Charset.forName(Iterables.getOnlyElement(charsetValues)));
346 default:
347 throw new IllegalStateException("Multiple charset values defined: " + charsetValues);
348 }
349 }
350
351 /**
352 * Returns a new instance with the same type and subtype as this instance, but without any
353 * parameters.
354 */
355 public MediaType withoutParameters() {
356 return parameters.isEmpty() ? this : create(type, subtype);
357 }
358
359 /**
360 * <em>Replaces</em> all parameters with the given parameters.
361 *
362 * @throws IllegalArgumentException if any parameter or value is invalid
363 */
364 public MediaType withParameters(Multimap<String, String> parameters) {
365 return create(type, subtype, parameters);
366 }
367
368 /**
369 * <em>Replaces</em> all parameters with the given attribute with a single parameter with the
370 * given value. If multiple parameters with the same attributes are necessary use
371 * {@link #withParameters}. Prefer {@link #withCharset} for setting the {@code charset} parameter
372 * when using a {@link Charset} object.
373 *
374 * @throws IllegalArgumentException if either {@code attribute} or {@code value} is invalid
375 */
376 public MediaType withParameter(String attribute, String value) {
377 checkNotNull(attribute);
378 checkNotNull(value);
379 String normalizedAttribute = normalizeToken(attribute);
380 ImmutableListMultimap.Builder<String, String> builder = ImmutableListMultimap.builder();
381 for (Entry<String, String> entry : parameters.entries()) {
382 String key = entry.getKey();
383 if (!normalizedAttribute.equals(key)) {
384 builder.put(key, entry.getValue());
385 }
386 }
387 builder.put(normalizedAttribute, normalizeParameterValue(normalizedAttribute, value));
388 MediaType mediaType = new MediaType(type, subtype, builder.build());
389 // Return one of the constants if the media type is a known type.
390 return Objects.firstNonNull(KNOWN_TYPES.get(mediaType), mediaType);
391 }
392
393 /**
394 * Returns a new instance with the same type and subtype as this instance, with the
395 * {@code charset} parameter set to the {@link Charset#name name} of the given charset. Only one
396 * {@code charset} parameter will be present on the new instance regardless of the number set on
397 * this one.
398 *
399 * <p>If a charset must be specified that is not supported on this JVM (and thus is not
400 * representable as a {@link Charset} instance, use {@link #withParameter}.
401 */
402 public MediaType withCharset(Charset charset) {
403 checkNotNull(charset);
404 return withParameter(CHARSET_ATTRIBUTE, charset.name());
405 }
406
407 /** Returns true if either the type or subtype is the wildcard. */
408 public boolean hasWildcard() {
409 return WILDCARD.equals(type) || WILDCARD.equals(subtype);
410 }
411
412 /**
413 * Returns {@code true} if this instance falls within the range (as defined by
414 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html">the HTTP Accept header</a>)
415 * given by the argument according to three criteria:
416 *
417 * <ol>
418 * <li>The type of the argument is the wildcard or equal to the type of this instance.
419 * <li>The subtype of the argument is the wildcard or equal to the subtype of this instance.
420 * <li>All of the parameters present in the argument are present in this instance.
421 * </ol>
422 *
423 * For example: <pre> {@code
424 * PLAIN_TEXT_UTF_8.is(PLAIN_TEXT_UTF_8) // true
425 * PLAIN_TEXT_UTF_8.is(HTML_UTF_8) // false
426 * PLAIN_TEXT_UTF_8.is(ANY_TYPE) // true
427 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE) // true
428 * PLAIN_TEXT_UTF_8.is(ANY_IMAGE_TYPE) // false
429 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE.withCharset(UTF_8)) // true
430 * PLAIN_TEXT_UTF_8.withoutParameters().is(ANY_TEXT_TYPE.withCharset(UTF_8)) // false
431 * PLAIN_TEXT_UTF_8.is(ANY_TEXT_TYPE.withCharset(UTF_16)) // false}</pre>
432 *
433 * <p>Note that while it is possible to have the same parameter declared multiple times within a
434 * media type this method does not consider the number of occurrences of a parameter. For
435 * example, {@code "text/plain; charset=UTF-8"} satisfies
436 * {@code "text/plain; charset=UTF-8; charset=UTF-8"}.
437 */
438 public boolean is(MediaType mediaTypeRange) {
439 return (mediaTypeRange.type.equals(WILDCARD) || mediaTypeRange.type.equals(this.type))
440 && (mediaTypeRange.subtype.equals(WILDCARD) || mediaTypeRange.subtype.equals(this.subtype))
441 && this.parameters.entries().containsAll(mediaTypeRange.parameters.entries());
442 }
443
444 /**
445 * Creates a new media type with the given type and subtype.
446 *
447 * @throws IllegalArgumentException if type or subtype is invalid or if a wildcard is used for the
448 * type, but not the subtype.
449 */
450 public static MediaType create(String type, String subtype) {
451 return create(type, subtype, ImmutableListMultimap.<String, String>of());
452 }
453
454 /**
455 * Creates a media type with the "application" type and the given subtype.
456 *
457 * @throws IllegalArgumentException if subtype is invalid
458 */
459 static MediaType createApplicationType(String subtype) {
460 return create(APPLICATION_TYPE, subtype);
461 }
462
463 /**
464 * Creates a media type with the "audio" type and the given subtype.
465 *
466 * @throws IllegalArgumentException if subtype is invalid
467 */
468 static MediaType createAudioType(String subtype) {
469 return create(AUDIO_TYPE, subtype);
470 }
471
472 /**
473 * Creates a media type with the "image" type and the given subtype.
474 *
475 * @throws IllegalArgumentException if subtype is invalid
476 */
477 static MediaType createImageType(String subtype) {
478 return create(IMAGE_TYPE, subtype);
479 }
480
481 /**
482 * Creates a media type with the "text" type and the given subtype.
483 *
484 * @throws IllegalArgumentException if subtype is invalid
485 */
486 static MediaType createTextType(String subtype) {
487 return create(TEXT_TYPE, subtype);
488 }
489
490 /**
491 * Creates a media type with the "video" type and the given subtype.
492 *
493 * @throws IllegalArgumentException if subtype is invalid
494 */
495 static MediaType createVideoType(String subtype) {
496 return create(VIDEO_TYPE, subtype);
497 }
498
499 private static MediaType create(String type, String subtype,
500 Multimap<String, String> parameters) {
501 checkNotNull(type);
502 checkNotNull(subtype);
503 checkNotNull(parameters);
504 String normalizedType = normalizeToken(type);
505 String normalizedSubtype = normalizeToken(subtype);
506 checkArgument(!WILDCARD.equals(normalizedType) || WILDCARD.equals(normalizedSubtype),
507 "A wildcard type cannot be used with a non-wildcard subtype");
508 ImmutableListMultimap.Builder<String, String> builder = ImmutableListMultimap.builder();
509 for (Entry<String, String> entry : parameters.entries()) {
510 String attribute = normalizeToken(entry.getKey());
511 builder.put(attribute, normalizeParameterValue(attribute, entry.getValue()));
512 }
513 MediaType mediaType = new MediaType(normalizedType, normalizedSubtype, builder.build());
514 // Return one of the constants if the media type is a known type.
515 return Objects.firstNonNull(KNOWN_TYPES.get(mediaType), mediaType);
516 }
517
518 private static String normalizeToken(String token) {
519 checkArgument(TOKEN_MATCHER.matchesAllOf(token));
520 return Ascii.toLowerCase(token);
521 }
522
523 private static String normalizeParameterValue(String attribute, String value) {
524 return CHARSET_ATTRIBUTE.equals(attribute) ? Ascii.toLowerCase(value) : value;
525 }
526
527 /**
528 * Parses a media type from its string representation.
529 *
530 * @throws IllegalArgumentException if the input is not parsable
531 */
532 public static MediaType parse(String input) {
533 checkNotNull(input);
534 Tokenizer tokenizer = new Tokenizer(input);
535 try {
536 String type = tokenizer.consumeToken(TOKEN_MATCHER);
537 tokenizer.consumeCharacter('/');
538 String subtype = tokenizer.consumeToken(TOKEN_MATCHER);
539 ImmutableListMultimap.Builder<String, String> parameters = ImmutableListMultimap.builder();
540 while (tokenizer.hasMore()) {
541 tokenizer.consumeCharacter(';');
542 tokenizer.consumeTokenIfPresent(LINEAR_WHITE_SPACE);
543 String attribute = tokenizer.consumeToken(TOKEN_MATCHER);
544 tokenizer.consumeCharacter('=');
545 final String value;
546 if ('"' == tokenizer.previewChar()) {
547 tokenizer.consumeCharacter('"');
548 StringBuilder valueBuilder = new StringBuilder();
549 while ('"' != tokenizer.previewChar()) {
550 if ('\\' == tokenizer.previewChar()) {
551 tokenizer.consumeCharacter('\\');
552 valueBuilder.append(tokenizer.consumeCharacter(ASCII));
553 } else {
554 valueBuilder.append(tokenizer.consumeToken(QUOTED_TEXT_MATCHER));
555 }
556 }
557 value = valueBuilder.toString();
558 tokenizer.consumeCharacter('"');
559 } else {
560 value = tokenizer.consumeToken(TOKEN_MATCHER);
561 }
562 parameters.put(attribute, value);
563 }
564 return create(type, subtype, parameters.build());
565 } catch (IllegalStateException e) {
566 throw new IllegalArgumentException(e);
567 }
568 }
569
570 private static final class Tokenizer {
571 final String input;
572 int position = 0;
573
574 Tokenizer(String input) {
575 this.input = input;
576 }
577
578 String consumeTokenIfPresent(CharMatcher matcher) {
579 checkState(hasMore());
580 int startPosition = position;
581 position = matcher.negate().indexIn(input, startPosition);
582 return hasMore() ? input.substring(startPosition, position) : input.substring(startPosition);
583 }
584
585 String consumeToken(CharMatcher matcher) {
586 int startPosition = position;
587 String token = consumeTokenIfPresent(matcher);
588 checkState(position != startPosition);
589 return token;
590 }
591
592 char consumeCharacter(CharMatcher matcher) {
593 checkState(hasMore());
594 char c = previewChar();
595 checkState(matcher.matches(c));
596 position++;
597 return c;
598 }
599
600 char consumeCharacter(char c) {
601 checkState(hasMore());
602 checkState(previewChar() == c);
603 position++;
604 return c;
605 }
606
607 char previewChar() {
608 checkState(hasMore());
609 return input.charAt(position);
610 }
611
612 boolean hasMore() {
613 return (position >= 0) && (position < input.length());
614 }
615 }
616
617 @Override public boolean equals(@Nullable Object obj) {
618 if (obj == this) {
619 return true;
620 } else if (obj instanceof MediaType) {
621 MediaType that = (MediaType) obj;
622 return this.type.equals(that.type)
623 && this.subtype.equals(that.subtype)
624 // compare parameters regardless of order
625 && this.parametersAsMap().equals(that.parametersAsMap());
626 } else {
627 return false;
628 }
629 }
630
631 @Override public int hashCode() {
632 return Objects.hashCode(type, subtype, parametersAsMap());
633 }
634
635 private static final MapJoiner PARAMETER_JOINER = Joiner.on("; ").withKeyValueSeparator("=");
636
637 /**
638 * Returns the string representation of this media type in the format described in <a
639 * href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>.
640 */
641 @Override public String toString() {
642 StringBuilder builder = new StringBuilder().append(type).append('/').append(subtype);
643 if (!parameters.isEmpty()) {
644 builder.append("; ");
645 Multimap<String, String> quotedParameters = Multimaps.transformValues(parameters,
646 new Function<String, String>() {
647 @Override public String apply(String value) {
648 return TOKEN_MATCHER.matchesAllOf(value) ? value : escapeAndQuote(value);
649 }
650 });
651 PARAMETER_JOINER.appendTo(builder, quotedParameters.entries());
652 }
653 return builder.toString();
654 }
655
656 private static String escapeAndQuote(String value) {
657 StringBuilder escaped = new StringBuilder(value.length() + 16).append('"');
658 for (char ch : value.toCharArray()) {
659 if (ch == '\r' || ch == '\\' || ch == '"') {
660 escaped.append('\\');
661 }
662 escaped.append(ch);
663 }
664 return escaped.append('"').toString();
665 }
666
667 }