001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027 028package org.apache.http.message; 029 030import org.apache.http.HeaderElement; 031import org.apache.http.NameValuePair; 032import org.apache.http.ParseException; 033import org.apache.http.util.CharArrayBuffer; 034 035/** 036 * Interface for parsing header values into elements. 037 * Instances of this interface are expected to be stateless and thread-safe. 038 * 039 * @since 4.0 040 */ 041public interface HeaderValueParser { 042 043 /** 044 * Parses a header value into elements. 045 * Parse errors are indicated as {@code RuntimeException}. 046 * <p> 047 * Some HTTP headers (such as the set-cookie header) have values that 048 * can be decomposed into multiple elements. In order to be processed 049 * by this parser, such headers must be in the following form: 050 * </p> 051 * <pre> 052 * header = [ element ] *( "," [ element ] ) 053 * element = name [ "=" [ value ] ] *( ";" [ param ] ) 054 * param = name [ "=" [ value ] ] 055 * 056 * name = token 057 * value = ( token | quoted-string ) 058 * 059 * token = 1*<any char except "=", ",", ";", <"> and 060 * white space> 061 * quoted-string = <"> *( text | quoted-char ) <"> 062 * text = any char except <"> 063 * quoted-char = "\" char 064 * </pre> 065 * <p> 066 * Any amount of white space is allowed between any part of the 067 * header, element or param and is ignored. A missing value in any 068 * element or param will be stored as the empty {@link String}; 069 * if the "=" is also missing <var>null</var> will be stored instead. 070 * </p> 071 * 072 * @param buffer buffer holding the header value to parse 073 * @param cursor the parser cursor containing the current position and 074 * the bounds within the buffer for the parsing operation 075 * 076 * @return an array holding all elements of the header value 077 * 078 * @throws ParseException in case of a parsing error 079 */ 080 HeaderElement[] parseElements( 081 CharArrayBuffer buffer, 082 ParserCursor cursor) throws ParseException; 083 084 /** 085 * Parses a single header element. 086 * A header element consist of a semicolon-separate list 087 * of name=value definitions. 088 * 089 * @param buffer buffer holding the element to parse 090 * @param cursor the parser cursor containing the current position and 091 * the bounds within the buffer for the parsing operation 092 * 093 * @return the parsed element 094 * 095 * @throws ParseException in case of a parse error 096 */ 097 HeaderElement parseHeaderElement( 098 CharArrayBuffer buffer, 099 ParserCursor cursor) throws ParseException; 100 101 /** 102 * Parses a list of name-value pairs. 103 * These lists are used to specify parameters to a header element. 104 * Parse errors are indicated as {@code ParseException}. 105 * 106 * @param buffer buffer holding the name-value list to parse 107 * @param cursor the parser cursor containing the current position and 108 * the bounds within the buffer for the parsing operation 109 * 110 * @return an array holding all items of the name-value list 111 * 112 * @throws ParseException in case of a parse error 113 */ 114 NameValuePair[] parseParameters( 115 CharArrayBuffer buffer, 116 ParserCursor cursor) throws ParseException; 117 118 119 /** 120 * Parses a name=value specification, where the = and value are optional. 121 * 122 * @param buffer the buffer holding the name-value pair to parse 123 * @param cursor the parser cursor containing the current position and 124 * the bounds within the buffer for the parsing operation 125 * 126 * @return the name-value pair, where the value is {@code null} 127 * if no value is specified 128 */ 129 NameValuePair parseNameValuePair( 130 CharArrayBuffer buffer, 131 ParserCursor cursor) throws ParseException; 132 133} 134