/* * $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 * . * */ 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. * * * * @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 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 {@link String}; * if the "=" is also missing null will be stored instead. *

* * @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 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
     * 
* * @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 null * if no value is specified */ NameValuePair parseNameValuePair( CharArrayBuffer buffer, ParserCursor cursor) throws ParseException; }