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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.HttpException;
32  import org.apache.http.HttpMessage;
33  import org.apache.http.HttpVersion;
34  import org.apache.http.ProtocolException;
35  import org.apache.http.annotation.Immutable;
36  import org.apache.http.entity.ContentLengthStrategy;
37  import org.apache.http.protocol.HTTP;
38  import org.apache.http.util.Args;
39  
40  /**
41   * The strict implementation of the content length strategy. This class
42   * will throw {@link ProtocolException} if it encounters an unsupported
43   * transfer encoding or a malformed {@code Content-Length} header
44   * value.
45   * <p>
46   * This class recognizes "chunked" and "identitiy" transfer-coding only.
47   *
48   * @since 4.0
49   */
50  @Immutable
51  public class StrictContentLengthStrategy implements ContentLengthStrategy {
52  
53      public static final StrictContentLengthStrategy INSTANCE = new StrictContentLengthStrategy();
54  
55      private final int implicitLen;
56  
57      /**
58       * Creates {@code StrictContentLengthStrategy} instance with the given length used per default
59       * when content length is not explicitly specified in the message.
60       *
61       * @param implicitLen implicit content length.
62       *
63       * @since 4.2
64       */
65      public StrictContentLengthStrategy(final int implicitLen) {
66          super();
67          this.implicitLen = implicitLen;
68      }
69  
70      /**
71       * Creates {@code StrictContentLengthStrategy} instance. {@link ContentLengthStrategy#IDENTITY}
72       * is used per default when content length is not explicitly specified in the message.
73       */
74      public StrictContentLengthStrategy() {
75          this(IDENTITY);
76      }
77  
78      @Override
79      public long determineLength(final HttpMessage message) throws HttpException {
80          Args.notNull(message, "HTTP message");
81          // Although Transfer-Encoding is specified as a list, in practice
82          // it is either missing or has the single value "chunked". So we
83          // treat it as a single-valued header here.
84          final Header transferEncodingHeader = message.getFirstHeader(HTTP.TRANSFER_ENCODING);
85          if (transferEncodingHeader != null) {
86              final String s = transferEncodingHeader.getValue();
87              if (HTTP.CHUNK_CODING.equalsIgnoreCase(s)) {
88                  if (message.getProtocolVersion().lessEquals(HttpVersion.HTTP_1_0)) {
89                      throw new ProtocolException(
90                              "Chunked transfer encoding not allowed for " +
91                              message.getProtocolVersion());
92                  }
93                  return CHUNKED;
94              } else if (HTTP.IDENTITY_CODING.equalsIgnoreCase(s)) {
95                  return IDENTITY;
96              } else {
97                  throw new ProtocolException(
98                          "Unsupported transfer encoding: " + s);
99              }
100         }
101         final Header contentLengthHeader = message.getFirstHeader(HTTP.CONTENT_LEN);
102         if (contentLengthHeader != null) {
103             final String s = contentLengthHeader.getValue();
104             try {
105                 final long len = Long.parseLong(s);
106                 if (len < 0) {
107                     throw new ProtocolException("Negative content length: " + s);
108                 }
109                 return len;
110             } catch (final NumberFormatException e) {
111                 throw new ProtocolException("Invalid content length: " + s);
112             }
113         }
114         return this.implicitLen;
115     }
116 
117 }