1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.impl.entity;
29
30 import org.apache.http.Header;
31 import org.apache.http.HeaderElement;
32 import org.apache.http.HttpException;
33 import org.apache.http.HttpMessage;
34 import org.apache.http.ParseException;
35 import org.apache.http.ProtocolException;
36 import org.apache.http.annotation.ThreadingBehavior;
37 import org.apache.http.annotation.Contract;
38 import org.apache.http.entity.ContentLengthStrategy;
39 import org.apache.http.protocol.HTTP;
40 import org.apache.http.util.Args;
41
42 /**
43 * The lax implementation of the content length strategy. This class will ignore
44 * unrecognized transfer encodings and malformed {@code Content-Length}
45 * header values.
46 * <p>
47 * This class recognizes "chunked" and "identitiy" transfer-coding only.
48 *
49 * @since 4.0
50 */
51 @Contract(threading = ThreadingBehavior.IMMUTABLE)
52 public class LaxContentLengthStrategy implements ContentLengthStrategy {
53
54 public static final LaxContentLengthStrategytrategy.html#LaxContentLengthStrategy">LaxContentLengthStrategy INSTANCE = new LaxContentLengthStrategy();
55
56 private final int implicitLen;
57
58 /**
59 * Creates {@code LaxContentLengthStrategy} instance with the given length used per default
60 * when content length is not explicitly specified in the message.
61 *
62 * @param implicitLen implicit content length.
63 *
64 * @since 4.2
65 */
66 public LaxContentLengthStrategy(final int implicitLen) {
67 super();
68 this.implicitLen = implicitLen;
69 }
70
71 /**
72 * Creates {@code LaxContentLengthStrategy} instance. {@link ContentLengthStrategy#IDENTITY}
73 * is used per default when content length is not explicitly specified in the message.
74 */
75 public LaxContentLengthStrategy() {
76 this(IDENTITY);
77 }
78
79 @Override
80 public long determineLength(final HttpMessage message) throws HttpException {
81 Args.notNull(message, "HTTP message");
82
83 final Header transferEncodingHeader = message.getFirstHeader(HTTP.TRANSFER_ENCODING);
84 // We use Transfer-Encoding if present and ignore Content-Length.
85 // RFC2616, 4.4 item number 3
86 if (transferEncodingHeader != null) {
87 final HeaderElement[] encodings;
88 try {
89 encodings = transferEncodingHeader.getElements();
90 } catch (final ParseException px) {
91 throw new ProtocolException
92 ("Invalid Transfer-Encoding header value: " +
93 transferEncodingHeader, px);
94 }
95 // The chunked encoding must be the last one applied RFC2616, 14.41
96 final int len = encodings.length;
97 if (HTTP.IDENTITY_CODING.equalsIgnoreCase(transferEncodingHeader.getValue())) {
98 return IDENTITY;
99 } else if ((len > 0) && (HTTP.CHUNK_CODING.equalsIgnoreCase(
100 encodings[len - 1].getName()))) {
101 return CHUNKED;
102 } else {
103 return IDENTITY;
104 }
105 }
106 final Header contentLengthHeader = message.getFirstHeader(HTTP.CONTENT_LEN);
107 if (contentLengthHeader != null) {
108 long contentLen = -1;
109 final Header[] headers = message.getHeaders(HTTP.CONTENT_LEN);
110 for (int i = headers.length - 1; i >= 0; i--) {
111 final Header header = headers[i];
112 try {
113 contentLen = Long.parseLong(header.getValue());
114 break;
115 } catch (final NumberFormatException ignore) {
116 }
117 // See if we can have better luck with another header, if present
118 }
119 return contentLen >= 0 ? contentLen : IDENTITY;
120 }
121 return this.implicitLen;
122 }
123
124 }