1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/entity/StrictContentLengthStrategy.java $ 3 * $Revision: 573949 $ 4 * $Date: 2007-09-08 22:46:25 -0700 (Sat, 08 Sep 2007) $ 5 * 6 * ==================================================================== 7 * Licensed to the Apache Software Foundation (ASF) under one 8 * or more contributor license agreements. See the NOTICE file 9 * distributed with this work for additional information 10 * regarding copyright ownership. The ASF licenses this file 11 * to you under the Apache License, Version 2.0 (the 12 * "License"); you may not use this file except in compliance 13 * with the License. You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, 18 * software distributed under the License is distributed on an 19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 20 * KIND, either express or implied. See the License for the 21 * specific language governing permissions and limitations 22 * under the License. 23 * ==================================================================== 24 * 25 * This software consists of voluntary contributions made by many 26 * individuals on behalf of the Apache Software Foundation. For more 27 * information on the Apache Software Foundation, please see 28 * <http://www.apache.org/>. 29 * 30 */ 31 32 package org.apache.http.impl.entity; 33 34 import org.apache.http.Header; 35 import org.apache.http.HttpException; 36 import org.apache.http.HttpMessage; 37 import org.apache.http.HttpVersion; 38 import org.apache.http.ProtocolException; 39 import org.apache.http.entity.ContentLengthStrategy; 40 import org.apache.http.protocol.HTTP; 41 42 /** 43 * The strict implementation of the content length strategy. 44 * <p> 45 * This entity generator comforms to the entity transfer rules outlined in the 46 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec4.4">Section 4.4</a>, 47 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.6">Section 3.6</a>, 48 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.41">Section 14.41</a> 49 * and <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec14.13">Section 14.13</a> 50 * of <a href="http://www.w3.org/Protocols/rfc2616/rfc2616.txt">RFC 2616</a> 51 * </p> 52 * <h>4.4 Message Length</h> 53 * <p> 54 * The transfer-length of a message is the length of the message-body as it appears in the 55 * message; that is, after any transfer-codings have been applied. When a message-body is 56 * included with a message, the transfer-length of that body is determined by one of the 57 * following (in order of precedence): 58 * </p> 59 * <p> 60 * 1.Any response message which "MUST NOT" include a message-body (such as the 1xx, 204, 61 * and 304 responses and any response to a HEAD request) is always terminated by the first 62 * empty line after the header fields, regardless of the entity-header fields present in the 63 * message. 64 * </p> 65 * <p> 66 * 2.If a Transfer-Encoding header field (section 14.41) is present and has any value other 67 * than "identity", then the transfer-length is defined by use of the "chunked" transfer- 68 * coding (section 3.6), unless the message is terminated by closing the connection. 69 * </p> 70 * <p> 71 * 3.If a Content-Length header field (section 14.13) is present, its decimal value in 72 * OCTETs represents both the entity-length and the transfer-length. The Content-Length 73 * header field MUST NOT be sent if these two lengths are different (i.e., if a 74 * Transfer-Encoding 75 * </p> 76 * <pre> 77 * header field is present). If a message is received with both a 78 * Transfer-Encoding header field and a Content-Length header field, 79 * the latter MUST be ignored. 80 * </pre> 81 * <p> 82 * 4.If the message uses the media type "multipart/byteranges", and the ransfer-length is not 83 * otherwise specified, then this self- elimiting media type defines the transfer-length. 84 * This media type UST NOT be used unless the sender knows that the recipient can arse it; the 85 * presence in a request of a Range header with ultiple byte- range specifiers from a 1.1 86 * client implies that the lient can parse multipart/byteranges responses. 87 * </p> 88 * <pre> 89 * A range header might be forwarded by a 1.0 proxy that does not 90 * understand multipart/byteranges; in this case the server MUST 91 * delimit the message using methods defined in items 1,3 or 5 of 92 * this section. 93 * </pre> 94 * <p> 95 * 5.By the server closing the connection. (Closing the connection cannot be used to indicate 96 * the end of a request body, since that would leave no possibility for the server to send back 97 * a response.) 98 * </p> 99 * <p> 100 * For compatibility with HTTP/1.0 applications, HTTP/1.1 requests containing a message-body 101 * MUST include a valid Content-Length header field unless the server is known to be HTTP/1.1 102 * compliant. If a request contains a message-body and a Content-Length is not given, the 103 * server SHOULD respond with 400 (bad request) if it cannot determine the length of the 104 * message, or with 411 (length required) if it wishes to insist on receiving a valid 105 * Content-Length. 106 * </p> 107 * <p>All HTTP/1.1 applications that receive entities MUST accept the "chunked" transfer-coding 108 * (section 3.6), thus allowing this mechanism to be used for messages when the message 109 * length cannot be determined in advance. 110 * </p> 111 * <h>3.6 Transfer Codings</h> 112 * <p> 113 * Transfer-coding values are used to indicate an encoding transformation that 114 * has been, can be, or may need to be applied to an entity-body in order to ensure 115 * "safe transport" through the network. This differs from a content coding in that 116 * the transfer-coding is a property of the message, not of the original entity. 117 * </p> 118 * <pre> 119 * transfer-coding = "chunked" | transfer-extension 120 * transfer-extension = token *( ";" parameter ) 121 * </pre> 122 * <p> 123 * Parameters are in the form of attribute/value pairs. 124 * </p> 125 * <pre> 126 * parameter = attribute "=" value 127 * attribute = token 128 * value = token | quoted-string 129 * </pre> 130 * <p> 131 * All transfer-coding values are case-insensitive. HTTP/1.1 uses transfer-coding values in 132 * the TE header field (section 14.39) and in the Transfer-Encoding header field (section 14.41). 133 * </p> 134 * <p> 135 * Whenever a transfer-coding is applied to a message-body, the set of transfer-codings MUST 136 * include "chunked", unless the message is terminated by closing the connection. When the 137 * "chunked" transfer-coding is used, it MUST be the last transfer-coding applied to the 138 * message-body. The "chunked" transfer-coding MUST NOT be applied more than once to a 139 * message-body. These rules allow the recipient to determine the transfer-length of the 140 * message (section 4.4). 141 * </p> 142 * <h>14.41 Transfer-Encoding</h> 143 * <p> 144 * The Transfer-Encoding general-header field indicates what (if any) type of transformation has 145 * been applied to the message body in order to safely transfer it between the sender and the 146 * recipient. This differs from the content-coding in that the transfer-coding is a property of 147 * the message, not of the entity. 148 * </p> 149 * <pre> 150 * Transfer-Encoding = "Transfer-Encoding" ":" 1#transfer-coding 151 * </pre> 152 * <p> 153 * If multiple encodings have been applied to an entity, the transfer- codings MUST be listed in 154 * the order in which they were applied. Additional information about the encoding parameters 155 * MAY be provided by other entity-header fields not defined by this specification. 156 * </p> 157 * <h>14.13 Content-Length</h> 158 * <p> 159 * The Content-Length entity-header field indicates the size of the entity-body, in decimal 160 * number of OCTETs, sent to the recipient or, in the case of the HEAD method, the size of 161 * the entity-body that would have been sent had the request been a GET. 162 * </p> 163 * <pre> 164 * Content-Length = "Content-Length" ":" 1*DIGIT 165 * </pre> 166 * <p> 167 * Applications SHOULD use this field to indicate the transfer-length of the message-body, 168 * unless this is prohibited by the rules in section 4.4. 169 * </p> 170 * 171 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a> 172 * 173 * @version $Revision: 573949 $ 174 * 175 * @since 4.0 176 */ 177 public class StrictContentLengthStrategy implements ContentLengthStrategy { 178 179 public StrictContentLengthStrategy() { 180 super(); 181 } 182 183 public long determineLength(final HttpMessage message) throws HttpException { 184 if (message == null) { 185 throw new IllegalArgumentException("HTTP message may not be null"); 186 } 187 // Although Transfer-Encoding is specified as a list, in practice 188 // it is either missing or has the single value "chunked". So we 189 // treat it as a single-valued header here. 190 Header transferEncodingHeader = message.getFirstHeader(HTTP.TRANSFER_ENCODING); 191 Header contentLengthHeader = message.getFirstHeader(HTTP.CONTENT_LEN); 192 if (transferEncodingHeader != null) { 193 String s = transferEncodingHeader.getValue(); 194 if (HTTP.CHUNK_CODING.equalsIgnoreCase(s)) { 195 if (message.getProtocolVersion().lessEquals(HttpVersion.HTTP_1_0)) { 196 throw new ProtocolException( 197 "Chunked transfer encoding not allowed for " + 198 message.getProtocolVersion()); 199 } 200 return CHUNKED; 201 } else if (HTTP.IDENTITY_CODING.equalsIgnoreCase(s)) { 202 return IDENTITY; 203 } else { 204 throw new ProtocolException( 205 "Unsupported transfer encoding: " + s); 206 } 207 } else if (contentLengthHeader != null) { 208 String s = contentLengthHeader.getValue(); 209 try { 210 long len = Long.parseLong(s); 211 return len; 212 } catch (NumberFormatException e) { 213 throw new ProtocolException("Invalid content length: " + s); 214 } 215 } else { 216 return IDENTITY; 217 } 218 } 219 220 } 221
