Package org.apache.http.message

Interface HeaderValueParser

All Known Implementing Classes:
BasicHeaderValueParser
public interface HeaderValueParser
Interface for parsing header values into elements. Instances of this interface are expected to be stateless and thread-safe.
Since:
4.0
Version:
$Revision: 589325 $ $Date: 2007-10-28 03:37:56 -0700 (Sun, 28 Oct 2007) $

  • Method Details

    • parseElements

      HeaderElement[] parseElements​(CharArrayBuffer buffer, ParserCursor cursor) throws ParseException
      Parses a header value into elements. Parse errors are indicated as RuntimeException.

      Some HTTP headers (such as the set-cookie header) have values that can be decomposed into multiple elements. In order to be processed by this parser, such headers must be in the following form: 

       header  = [ element ] *( "," [ element ] )
 element = name [ "=" [ value ] ] *( ";" [ param ] )
 param   = name [ "=" [ value ] ]

 name    = token
 value   = ( token | quoted-string )

 token         = 1*<any char except "=", ",", ";", <"> and
                       white space>
 quoted-string = <"> *( text | quoted-char ) <">
 text          = any char except <">
 quoted-char   = "\" char

      Any amount of white space is allowed between any part of the header, element or param and is ignored. A missing value in any element or param will be stored as the empty String; if the "=" is also missing null will be stored instead.

      Parameters:
      buffer - buffer holding the header value to parse
      cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation
      Returns:
      an array holding all elements of the header value
      Throws:
      ParseException - in case of a parse error

    • parseHeaderElement

      HeaderElement parseHeaderElement​(CharArrayBuffer buffer, ParserCursor cursor) throws ParseException
      Parses a single header element. A header element consist of a semicolon-separate list of name=value definitions.
      Parameters:
      buffer - buffer holding the element to parse
      cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation
      Returns:
      the parsed element
      Throws:
      ParseException - in case of a parse error

    • parseParameters

      NameValuePair[] parseParameters​(CharArrayBuffer buffer, ParserCursor cursor) throws ParseException
      Parses a list of name-value pairs. These lists are used to specify parameters to a header element. Parse errors are indicated as RuntimeException.

      This method comforms to the generic grammar and formatting rules outlined in the Section 2.2 and Section 3.6 of RFC 2616.

      2.2 Basic Rules

      The following rules are used throughout this specification to describe basic parsing constructs. The US-ASCII coded character set is defined by ANSI X3.4-1986. 

           OCTET          = 
     CHAR           = 
     UPALPHA        = 
     LOALPHA        = 
     ALPHA          = UPALPHA | LOALPHA
     DIGIT          = 
     CTL            = 
     CR             = 
     LF             = 
     SP             = 
     HT             = 
     <">            =

      Many HTTP/1.1 header field values consist of words separated by LWS or special characters. These special characters MUST be in a quoted string to be used within a parameter value (as defined in section 3.6). 

       token          = 1*
 separators     = "(" | ")" | "<" | ">" | "@"
                | "," | ";" | ":" | "\" | <">
                | "/" | "[" | "]" | "?" | "="
                | "{" | "}" | SP | HT

      A string of text is parsed as a single word if it is quoted using double-quote marks. 

       quoted-string  = ( <"> *(qdtext | quoted-pair ) <"> )
 qdtext         = >

      The backslash character ("\") MAY be used as a single-character quoting mechanism only within quoted-string and comment constructs. 

       quoted-pair    = "\" CHAR
      3.6 Transfer Codings

      Parameters are in the form of attribute/value pairs. 

       parameter               = attribute "=" value
 attribute               = token
 value                   = token | quoted-string
      Parameters:
      buffer - buffer holding the name-value list to parse
      cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation
      Returns:
      an array holding all items of the name-value list
      Throws:
      ParseException - in case of a parse error

    • parseNameValuePair

      NameValuePair parseNameValuePair​(CharArrayBuffer buffer, ParserCursor cursor) throws ParseException
      Parses a name=value specification, where the = and value are optional.
      Parameters:
      buffer - the buffer holding the name-value pair to parse
      cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation
      Returns:
      the name-value pair, where the value is null if no value is specified
      Throws:
      ParseException