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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.protocol;
29  
30  import java.io.IOException;
31  
32  import org.apache.http.HttpEntity;
33  import org.apache.http.HttpEntityEnclosingRequest;
34  import org.apache.http.HttpException;
35  import org.apache.http.HttpRequest;
36  import org.apache.http.HttpRequestInterceptor;
37  import org.apache.http.HttpVersion;
38  import org.apache.http.ProtocolVersion;
39  import org.apache.http.ProtocolException;
40  import org.apache.http.annotation.Immutable;
41  
42  /**
43   * RequestContent is the most important interceptor for outgoing requests.
44   * It is responsible for delimiting content length by adding
45   * <code>Content-Length</code> or <code>Transfer-Content</code> headers based
46   * on the properties of the enclosed entity and the protocol version.
47   * This interceptor is required for correct functioning of client side protocol
48   * processors.
49   *
50   * @since 4.0
51   */
52  @Immutable
53  public class RequestContent implements HttpRequestInterceptor {
54  
55      private final boolean overwrite;
56  
57      /**
58       * Default constructor. The <code>Content-Length</code> or <code>Transfer-Encoding</code>
59       * will cause the interceptor to throw {@link ProtocolException} if already present in the
60       * response message.
61       */
62      public RequestContent() {
63          this(false);
64      }
65  
66      /**
67       * Constructor that can be used to fine-tune behavior of this interceptor.
68       *
69       * @param overwrite If set to <code>true</code> the <code>Content-Length</code> and
70       * <code>Transfer-Encoding</code> headers will be created or updated if already present.
71       * If set to <code>false</code> the <code>Content-Length</code> and
72       * <code>Transfer-Encoding</code> headers will cause the interceptor to throw
73       * {@link ProtocolException} if already present in the response message.
74       * 
75       * @since 4.2
76       */
77       public RequestContent(boolean overwrite) {
78           super();
79           this.overwrite = overwrite;
80      }
81  
82      public void process(final HttpRequest request, final HttpContext context)
83              throws HttpException, IOException {
84          if (request == null) {
85              throw new IllegalArgumentException("HTTP request may not be null");
86          }
87          if (request instanceof HttpEntityEnclosingRequest) {
88              if (this.overwrite) {
89                  request.removeHeaders(HTTP.TRANSFER_ENCODING);
90                  request.removeHeaders(HTTP.CONTENT_LEN);
91              } else {
92                  if (request.containsHeader(HTTP.TRANSFER_ENCODING)) {
93                      throw new ProtocolException("Transfer-encoding header already present");
94                  }
95                  if (request.containsHeader(HTTP.CONTENT_LEN)) {
96                      throw new ProtocolException("Content-Length header already present");
97                  }
98              }
99              ProtocolVersion ver = request.getRequestLine().getProtocolVersion();
100             HttpEntity entity = ((HttpEntityEnclosingRequest)request).getEntity();
101             if (entity == null) {
102                 request.addHeader(HTTP.CONTENT_LEN, "0");
103                 return;
104             }
105             // Must specify a transfer encoding or a content length
106             if (entity.isChunked() || entity.getContentLength() < 0) {
107                 if (ver.lessEquals(HttpVersion.HTTP_1_0)) {
108                     throw new ProtocolException(
109                             "Chunked transfer encoding not allowed for " + ver);
110                 }
111                 request.addHeader(HTTP.TRANSFER_ENCODING, HTTP.CHUNK_CODING);
112             } else {
113                 request.addHeader(HTTP.CONTENT_LEN, Long.toString(entity.getContentLength()));
114             }
115             // Specify a content type if known
116             if (entity.getContentType() != null && !request.containsHeader(
117                     HTTP.CONTENT_TYPE )) {
118                 request.addHeader(entity.getContentType());
119             }
120             // Specify a content encoding if known
121             if (entity.getContentEncoding() != null && !request.containsHeader(
122                     HTTP.CONTENT_ENCODING)) {
123                 request.addHeader(entity.getContentEncoding());
124             }
125         }
126     }
127 
128 }