An HttpHeaders
is not typically created directly, but rather
returned from an HttpRequest
or an
HttpResponse
. Specific HTTP headers can be
set for a request through one of the request
builder's headers
methods.
The methods of this class ( that accept a String header name ), and the
Map
returned by the map
method, operate without regard
to case when retrieving the header value(s).
An HTTP header name may appear more than once in the HTTP protocol. As
such, headers are represented as a name and a list of values. Each occurrence
of a header value is added verbatim, to the appropriate header name list,
without interpreting its value. In particular, HttpHeaders
does not
perform any splitting or joining of comma separated header value strings. The
order of elements in a header value list is preserved when building
a request. For
responses, the order of elements in a header value list is the order in which
they were received. The Map
returned by the map
method,
however, does not provide any guarantee with regard to the ordering of its
entries.
HttpHeaders
instances are immutable.
- Since:
- 11
-
Method Summary
Modifier and TypeMethodDescriptionReturns an unmodifiable List of all of the header string values of the given named header.final boolean
Tests this HTTP headers instance for equality with the given object.firstValue
(String name) Returns anOptional
containing the first header string value of the given named (and possibly multi-valued) header.firstValueAsLong
(String name) Returns anOptionalLong
containing the first header string value of the named header field.final int
hashCode()
Computes a hash code for this HTTP headers instance.map()
Returns an unmodifiable multi Map view of this HttpHeaders.static HttpHeaders
Returns an HTTP headers from the given map.toString()
Returns this HTTP headers as a string.
-
Method Details
-
firstValue
Returns anOptional
containing the first header string value of the given named (and possibly multi-valued) header. If the header is not present, then the returnedOptional
is empty.- Parameters:
name
- the header name- Returns:
- an
Optional<String>
containing the first named header string value, if present
-
firstValueAsLong
Returns anOptionalLong
containing the first header string value of the named header field. If the header is not present, then the Optional is empty. If the header is present but contains a value that does not parse as aLong
value, then an exception is thrown.- Parameters:
name
- the header name- Returns:
- an
OptionalLong
- Throws:
NumberFormatException
- if a value is found, but does not parse as a Long
-
allValues
-
map
-
equals
Tests this HTTP headers instance for equality with the given object.If the given object is not an
HttpHeaders
then this method returnsfalse
. Two HTTP headers are equal if each of their corresponding maps are equal.This method satisfies the general contract of the
Object.equals
method. -
hashCode
public final int hashCode()Computes a hash code for this HTTP headers instance.The hash code is based upon the components of the HTTP headers
map
, and satisfies the general contract of theObject.hashCode
method. -
toString
-
of
Returns an HTTP headers from the given map. The given map's key represents the header name, and its value the list of string header values for that header name.An HTTP header name may appear more than once in the HTTP protocol. Such, multi-valued, headers must be represented by a single entry in the given map, whose entry value is a list that represents the multiple header string values. Leading and trailing whitespaces are removed from all string values retrieved from the given map and its lists before processing. Only headers that, after filtering, contain at least one, possibly empty string, value will be added to the HTTP headers.
- API Note:
- The primary purpose of this method is for testing frameworks.
Per-request headers can be set through one of the
HttpRequest
headers
methods. - Parameters:
headerMap
- the map containing the header names and valuesfilter
- a filter that can be used to inspect each header-name-and-value pair in the given map to determine if it should, or should not, be added to the to the HTTP headers- Returns:
- an HTTP headers instance containing the given headers
- Throws:
NullPointerException
- if any of:headerMap
, a key or value in the given map, or an entry in the map's value list, orfilter
, isnull
IllegalArgumentException
- if the givenheaderMap
contains any two keys that are equal ( without regard to case ); or if the given map contains any key whose length, after trimming whitespaces, is0
-