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.util.CharArrayBuffer; 033 034/** 035 * Interface for formatting elements of a header value. 036 * This is the complement to {@link HeaderValueParser}. 037 * Instances of this interface are expected to be stateless and thread-safe. 038 * 039 * <p> 040 * All formatting methods accept an optional buffer argument. 041 * If a buffer is passed in, the formatted element will be appended 042 * and the modified buffer is returned. If no buffer is passed in, 043 * a new buffer will be created and filled with the formatted element. 044 * In both cases, the caller is allowed to modify the returned buffer. 045 * </p> 046 * 047 * @since 4.0 048 */ 049public interface HeaderValueFormatter { 050 051 /** 052 * Formats an array of header elements. 053 * 054 * @param buffer the buffer to append to, or 055 * {@code null} to create a new buffer 056 * @param elems the header elements to format 057 * @param quote {@code true} to always format with quoted values, 058 * {@code false} to use quotes only when necessary 059 * 060 * @return a buffer with the formatted header elements. 061 * If the {@code buffer} argument was not {@code null}, 062 * that buffer will be used and returned. 063 */ 064 CharArrayBuffer formatElements(CharArrayBuffer buffer, 065 HeaderElement[] elems, 066 boolean quote); 067 068 /** 069 * Formats one header element. 070 * 071 * @param buffer the buffer to append to, or 072 * {@code null} to create a new buffer 073 * @param elem the header element to format 074 * @param quote {@code true} to always format with quoted values, 075 * {@code false} to use quotes only when necessary 076 * 077 * @return a buffer with the formatted header element. 078 * If the {@code buffer} argument was not {@code null}, 079 * that buffer will be used and returned. 080 */ 081 CharArrayBuffer formatHeaderElement(CharArrayBuffer buffer, 082 HeaderElement elem, 083 boolean quote); 084 085 /** 086 * Formats the parameters of a header element. 087 * That's a list of name-value pairs, to be separated by semicolons. 088 * This method will <i>not</i> generate a leading semicolon. 089 * 090 * @param buffer the buffer to append to, or 091 * {@code null} to create a new buffer 092 * @param nvps the parameters (name-value pairs) to format 093 * @param quote {@code true} to always format with quoted values, 094 * {@code false} to use quotes only when necessary 095 * 096 * @return a buffer with the formatted parameters. 097 * If the {@code buffer} argument was not {@code null}, 098 * that buffer will be used and returned. 099 */ 100 CharArrayBuffer formatParameters(CharArrayBuffer buffer, 101 NameValuePair[] nvps, 102 boolean quote); 103 104 /** 105 * Formats one name-value pair, where the value is optional. 106 * 107 * @param buffer the buffer to append to, or 108 * {@code null} to create a new buffer 109 * @param nvp the name-value pair to format 110 * @param quote {@code true} to always format with a quoted value, 111 * {@code false} to use quotes only when necessary 112 * 113 * @return a buffer with the formatted name-value pair. 114 * If the {@code buffer} argument was not {@code null}, 115 * that buffer will be used and returned. 116 */ 117 CharArrayBuffer formatNameValuePair(CharArrayBuffer buffer, 118 NameValuePair nvp, 119 boolean quote); 120 121} 122