| // *************************************************************************************************************************** |
| // * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * |
| // * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * |
| // * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * |
| // * with the License. You may obtain a copy of the License at * |
| // * * |
| // * http://www.apache.org/licenses/LICENSE-2.0 * |
| // * * |
| // * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * |
| // * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * |
| // * specific language governing permissions and limitations under the License. * |
| // *************************************************************************************************************************** |
| package org.apache.juneau.http.header; |
| |
| import static org.apache.juneau.http.header.Constants.*; |
| |
| import java.util.function.*; |
| |
| import org.apache.juneau.http.annotation.*; |
| import org.apache.juneau.internal.*; |
| |
| /** |
| * Represents a parsed <l>Accept</l> HTTP request header. |
| * |
| * <p> |
| * Content-Types that are acceptable for the response. |
| * |
| * <h5 class='figure'>Example</h5> |
| * <p class='bcode w800'> |
| * Accept: text/plain |
| * </p> |
| * |
| * <h5 class='topic'>RFC2616 Specification</h5> |
| * |
| * The Accept request-header field can be used to specify certain media types which are acceptable for the response. |
| * Accept headers can be used to indicate that the request is specifically limited to a small set of desired types, as |
| * in the case of a request for an in-line image. |
| * |
| * <p class='bcode w800'> |
| * Accept = "Accept" ": |
| * #( media-range [ accept-params ] ) |
| * |
| * media-range = ( "* /*" |
| * | ( type "/" "*" ) |
| * | ( type "/" subtype ) |
| * ) *( ";" parameter ) |
| * accept-params = ";" "q" "=" qvalue *( accept-extension ) |
| * accept-extension = ";" token [ "=" ( token | quoted-string ) ] |
| * </p> |
| * |
| * <p> |
| * The asterisk "*" character is used to group media types into ranges, with "* /*" indicating all media types and |
| * "type/*" indicating all subtypes of that type. |
| * The media-range MAY include media type parameters that are applicable to that range. |
| * |
| * <p> |
| * Each media-range MAY be followed by one or more accept-params, beginning with the "q" parameter for indicating a |
| * relative quality factor. |
| * The first "q" parameter (if any) separates the media-range parameter(s) from the accept-params. |
| * Quality factors allow the user or user agent to indicate the relative degree of preference for that media-range, |
| * using the qvalue scale from 0 to 1 (section 3.9). |
| * The default value is q=1. |
| * |
| * <p> |
| * Note: Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to |
| * historical practice. |
| * Although this prevents any media type parameter named "q" from being used with a media range, such an event is |
| * believed to be unlikely given the lack of any "q" parameters in the IANA |
| * media type registry and the rare usage of any media type parameters in Accept. |
| * Future media types are discouraged from registering any parameter named "q". |
| * |
| * <p> |
| * The example |
| * <p class='bcode w800'> |
| * Accept: audio/*; q=0.2, audio/basic |
| * </p> |
| * <p> |
| * SHOULD be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% |
| * mark-down in quality." |
| * |
| * <p> |
| * If no Accept header field is present, then it is assumed that the client accepts all media types. |
| * |
| * <p> |
| * If an Accept header field is present, and if the server cannot send a response which is acceptable according to the |
| * combined Accept field value, then the server SHOULD send a 406 (not acceptable) response. |
| * |
| * <p> |
| * A more elaborate example is |
| * <p class='bcode w800'> |
| * Accept: text/plain; q=0.5, text/html, |
| * text/x-dvi; q=0.8, text/x-c |
| * </p> |
| * |
| * <p> |
| * Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not |
| * exist, then send the |
| * text/x-dvi entity, and if that does not exist, send the text/plain entity." |
| * |
| * <p> |
| * Media ranges can be overridden by more specific media ranges or specific media types. |
| * If more than one media range applies to a given type, the most specific reference has precedence. |
| * For example, |
| * <p class='bcode w800'> |
| * Accept: text/ *, text/html, text/html;level=1, * /* |
| * </p> |
| * <p> |
| * have the following precedence: |
| * <ol> |
| * <li>text/html;level=1 |
| * <li>text/html |
| * <li>text/* |
| * <li>* /* |
| * </ol> |
| * |
| * <p> |
| * The media type quality factor associated with a given type is determined by finding the media range with the highest |
| * precedence which matches that type. |
| * For example, |
| * <p class='bcode w800'> |
| * Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1, |
| * text/html;level=2;q=0.4, * /*;q=0.5 |
| * </p> |
| * <p> |
| * would cause the following values to be associated: |
| * <p class='bcode w800'> |
| * text/html;level=1 = 1 |
| * text/html = 0.7 |
| * text/plain = 0.3 |
| * image/jpeg = 0.5 |
| * text/html;level=2 = 0.4 |
| * text/html;level=3 = 0.7 |
| * </p> |
| * |
| * <p> |
| * Note: A user agent might be provided with a default set of quality values for certain media ranges. |
| * However, unless the user agent is a closed system which cannot interact with other rendering agents, this default |
| * set ought to be configurable by the user. |
| * |
| * <ul class='seealso'> |
| * <li class='extlink'>{@doc ExtRFC2616} |
| * </ul> |
| */ |
| @Header("Accept") |
| public class Accept extends BasicMediaRangeArrayHeader { |
| |
| private static final long serialVersionUID = 1L; |
| private static final String NAME = "Accept"; |
| |
| private static final Cache<String,Accept> CACHE = new Cache<>(NOCACHE, CACHE_MAX_SIZE); |
| |
| // Constants |
| @SuppressWarnings("javadoc") |
| public static final Accept |
| APPLICATION_ATOM_XML = of("application/atom+xml"), |
| APPLICATION_FORM_URLENCODED = of("application/x-www-form-urlencoded"), |
| APPLICATION_JSON = of("application/json"), |
| APPLICATION_OCTET_STREAM = of("application/octet-stream"), |
| APPLICATION_SOAP_XML = of("application/soap+xml"), |
| APPLICATION_SVG_XML = of("application/svg+xml"), |
| APPLICATION_XHTML_XML = of("application/xhtml+xml"), |
| APPLICATION_XML = of("application/xml"), |
| IMAGE_BMP = of("image/bmp"), |
| IMAGE_GIF = of("image/gif"), |
| IMAGE_JPEG = of("image/jpeg"), |
| IMAGE_PNG = of("image/png"), |
| IMAGE_SVG = of("image/svg+xml"), |
| IMAGE_TIFF = of("image/tiff"), |
| IMAGE_WEBP = of("image/webp"), |
| MULTIPART_FORM_DATA = of("multipart/form-data"), |
| TEXT_HTML = of("text/html"), |
| TEXT_PLAIN = of("text/plain"), |
| TEXT_XML = of("text/xml"), |
| WILDCARD = of("*/*"); |
| |
| /** |
| * Convenience creator. |
| * |
| * @param value |
| * The header value. |
| * <br>Must be parsable by {@link MediaRanges#of(String)}. |
| * <br>Can be <jk>null</jk>. |
| * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>. |
| */ |
| public static Accept of(String value) { |
| if (value == null) |
| return null; |
| Accept x = CACHE.get(value); |
| if (x == null) |
| x = CACHE.put(value, new Accept(value)); |
| return new Accept(value); |
| } |
| |
| /** |
| * Convenience creator. |
| * |
| * @param value |
| * The header value. |
| * <br>Can be <jk>null</jk>. |
| * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>. |
| */ |
| public static Accept of(MediaRanges value) { |
| if (value == null) |
| return null; |
| return new Accept(value); |
| } |
| |
| /** |
| * Convenience creator. |
| * |
| * @param value |
| * The header value. |
| * <br>Can be <jk>null</jk>. |
| * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>. |
| */ |
| public static Accept of(MediaType value) { |
| if (value == null) |
| return null; |
| return new Accept(value.toString()); |
| } |
| |
| /** |
| * Convenience creator with delayed value. |
| * |
| * <p> |
| * Header value is re-evaluated on each call to {@link #getValue()}. |
| * |
| * @param value |
| * The header value. |
| * <br>Can be <jk>null</jk>. |
| * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>. |
| */ |
| public static Accept of(Supplier<MediaRanges> value) { |
| if (value == null) |
| return null; |
| return new Accept(value); |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param value |
| * The header value. |
| * <br>Must be parsable by {@link MediaRanges#of(String)}. |
| * <br>Can be <jk>null</jk>. |
| */ |
| public Accept(String value) { |
| super(NAME, value); |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param value |
| * The header value. |
| * <br>Can be <jk>null</jk>. |
| */ |
| public Accept(MediaRanges value) { |
| super(NAME, value); |
| } |
| |
| /** |
| * Constructor with delayed value. |
| * |
| * <p> |
| * Header value is re-evaluated on each call to {@link #getValue()}. |
| * |
| * @param value |
| * The supplier of the header value. |
| * <br>Can be <jk>null</jk>. |
| */ |
| public Accept(Supplier<MediaRanges> value) { |
| super(NAME, value); |
| } |
| } |