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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *  http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.any23.http;
19  
20  import java.io.IOException;
21  import java.io.InputStream;
22  
23  /**
24   * Abstraction for opening an {@link InputStream} on an
25   * HTTP IRI.
26   *
27   * @author Richard Cyganiak (richard@cyganiak.de)
28   */
29  public interface HTTPClient {
30  
31      /**
32       * Initializes the HTTP client.
33       *
34       * @param configuration configuration for the HTTP Client.
35       */
36      void init(HTTPClientConfiguration configuration);
37  
38      /**
39       * Opens the input stream for the given target IRI.
40       *
41       * @param uri target IRI.
42       * @return input stream to access IRI content.
43       * @throws IOException if any error occurs while reading the IRI content.
44       */
45      InputStream openInputStream(String uri) throws IOException;
46  
47      /**
48       * Release all static resources help by the instance. Call this
49       * method only if you are sure you will not use it again in your
50       * application, like for example when shutting down a servlet
51       * context.
52       */
53      void close();
54  
55      /**
56       * The value of the Content-Type header reported by the server.
57       * Can be <tt>null</tt>.
58       *
59       * @return the content type as string.
60       */
61      String getContentType();
62  
63      /**
64       * @return content length in bytes.
65       */
66      long getContentLength();
67  
68      /**
69       * Returns the actual IRI from which the document was fetched.
70       * This might differ from the IRI passed to openInputStream()
71       * if a redirect was performed. A return value of <tt>null</tt>
72       * means that the IRI is unchanged and the original IRI was used.
73       *
74       * @return actual document IRI.
75       */
76      String getActualDocumentIRI();
77      
78  }