Content-Types that are acceptable for the response.
Accept = "Accept" ": #( media-range [ accept-params ] ) media-range = ( "* /*" | ( type "/" "*" ) | ( type "/" subtype ) ) *( ";" parameter ) accept-params = ";" "q" "=" qvalue *( accept-extension ) accept-extension = ";" token [ "=" ( token | quoted-string ) ]
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.
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.
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".
Accept: audio/*; q=0.2, audio/basic
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."
If no Accept header field is present, then it is assumed that the client accepts all media types.
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.
A more elaborate example is
Accept: text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c
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."
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,
Accept: text/ *, text/html, text/html;level=1, * /*
have the following precedence:
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,
Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, * /*;q=0.5
would cause the following values to be associated:
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
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.
|Modifier and Type||Method and Description|
Returns the list of the media ranges that make up this header.
Given a list of media types, returns the best match for this
Returns a parsed
Convenience method for searching through all of the subtypes of all the media ranges in this header for the presence of a subtype fragment.
public List<MediaTypeRange> asRanges()
The media ranges in the list are sorted by their q-value in descending order.
Note that fuzzy matching is allowed on the media types where the
Accept header may
contain additional subtype parts.
For example, given identical q-values and an
Accept value of
The purpose for this is to allow serializers to match when artifacts such as
id properties are
present in the header.
mediaTypes- The media types to match against.
-1if no suitable matches could be found.
public boolean hasSubtypePart(String part)
For example, given the header
part- The media type subtype fragment.
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