/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/message/HeaderValueParser.java $
* $Revision: 589325 $
* $Date: 2007-10-28 03:37:56 -0700 (Sun, 28 Oct 2007) $
*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.message;
import org.apache.http.HeaderElement;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.util.CharArrayBuffer;
/**
* Interface for parsing header values into elements.
* Instances of this interface are expected to be stateless and thread-safe.
*
*
* <!-- empty lines above to avoid 'svn diff' context problems -->
* @version $Revision: 589325 $ $Date: 2007-10-28 03:37:56 -0700 (Sun, 28 Oct 2007) $
*
* @since 4.0
*/
public interface HeaderValueParser {
/**
* Parses a header value into elements.
* Parse errors are indicated as <code>RuntimeException</code>.
* <p>
* 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:
* </p>
* <pre>
* 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
* </pre>
* <p>
* 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 {@link String};
* if the "=" is also missing <var>null</var> will be stored instead.
* </p>
*
* @param buffer buffer holding the header value to parse
* @param cursor the parser cursor containing the current position and
* the bounds within the buffer for the parsing operation
*
* @return an array holding all elements of the header value
*
* @throws ParseException in case of a parse error
*/
HeaderElement[] parseElements(
CharArrayBuffer buffer,
ParserCursor cursor) throws ParseException;
/**
* Parses a single header element.
* A header element consist of a semicolon-separate list
* of name=value definitions.
*
* @param buffer buffer holding the element to parse
* @param cursor the parser cursor containing the current position and
* the bounds within the buffer for the parsing operation
*
* @return the parsed element
*
* @throws ParseException in case of a parse error
*/
HeaderElement parseHeaderElement(
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 <code>RuntimeException</code>.
* <p>
* This method comforms to the generic grammar and formatting rules
* outlined in the
* <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2"
* >Section 2.2</a>
* and
* <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.6"
* >Section 3.6</a>
* of
* <a href="http://www.w3.org/Protocols/rfc2616/rfc2616.txt">RFC 2616</a>.
* </p>
* <h>2.2 Basic Rules</h>
* <p>
* 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.
* </p>
* <pre>
* OCTET = <any 8-bit sequence of data>
* CHAR = <any US-ASCII character (octets 0 - 127)>
* UPALPHA = <any US-ASCII uppercase letter "A".."Z">
* LOALPHA = <any US-ASCII lowercase letter "a".."z">
* ALPHA = UPALPHA | LOALPHA
* DIGIT = <any US-ASCII digit "0".."9">
* CTL = <any US-ASCII control character
* (octets 0 - 31) and DEL (127)>
* CR = <US-ASCII CR, carriage return (13)>
* LF = <US-ASCII LF, linefeed (10)>
* SP = <US-ASCII SP, space (32)>
* HT = <US-ASCII HT, horizontal-tab (9)>
* <"> = <US-ASCII double-quote mark (34)>
* </pre>
* <p>
* 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).
* <p>
* <pre>
* token = 1*<any CHAR except CTLs or separators>
* separators = "(" | ")" | "<" | ">" | "@"
* | "," | ";" | ":" | "\" | <">
* | "/" | "[" | "]" | "?" | "="
* | "{" | "}" | SP | HT
* </pre>
* <p>
* A string of text is parsed as a single word if it is quoted using
* double-quote marks.
* </p>
* <pre>
* quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
* qdtext = <any TEXT except <">>
* </pre>
* <p>
* The backslash character ("\") MAY be used as a single-character
* quoting mechanism only within quoted-string and comment constructs.
* </p>
* <pre>
* quoted-pair = "\" CHAR
* </pre>
* <h>3.6 Transfer Codings</h>
* <p>
* Parameters are in the form of attribute/value pairs.
* </p>
* <pre>
* parameter = attribute "=" value
* attribute = token
* value = token | quoted-string
* </pre>
*
* @param buffer buffer holding the name-value list to parse
* @param cursor the parser cursor containing the current position and
* the bounds within the buffer for the parsing operation
*
* @return an array holding all items of the name-value list
*
* @throws ParseException in case of a parse error
*/
NameValuePair[] parseParameters(
CharArrayBuffer buffer,
ParserCursor cursor) throws ParseException;
/**
* Parses a name=value specification, where the = and value are optional.
*
* @param buffer the buffer holding the name-value pair to parse
* @param cursor the parser cursor containing the current position and
* the bounds within the buffer for the parsing operation
*
* @return the name-value pair, where the value is <code>null</code>
* if no value is specified
*/
NameValuePair parseNameValuePair(
CharArrayBuffer buffer,
ParserCursor cursor) throws ParseException;
}