View Javadoc

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  package org.apache.http.client.protocol;
28  
29  import java.io.IOException;
30  
31  import org.apache.http.HttpException;
32  import org.apache.http.HttpRequest;
33  import org.apache.http.HttpRequestInterceptor;
34  import org.apache.http.annotation.Immutable;
35  import org.apache.http.protocol.HttpContext;
36  
37  /**
38   * Class responsible for handling Content Encoding requests in HTTP.
39   * <p>
40   * Instances of this class are stateless, therefore they're thread-safe and immutable.
41   *
42   * @see "http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.5"
43   *
44   * @since 4.1
45   */
46  @Immutable
47  public class RequestAcceptEncoding implements HttpRequestInterceptor {
48  
49      /**
50       * Adds the header {@code "Accept-Encoding: gzip,deflate"} to the request.
51       */
52      public void process(
53              final HttpRequest request,
54              final HttpContext context) throws HttpException, IOException {
55  
56          /* Signal support for Accept-Encoding transfer encodings. */
57          if (!request.containsHeader("Accept-Encoding")) {
58              request.addHeader("Accept-Encoding", "gzip,deflate");
59          }
60      }
61  
62  }