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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  package org.apache.hc.client5.http.entity;
28  
29  import java.io.IOException;
30  import java.io.InputStream;
31  import java.io.OutputStream;
32  
33  import org.apache.hc.core5.http.HttpEntity;
34  import org.apache.hc.core5.http.io.entity.HttpEntityWrapper;
35  import org.apache.hc.core5.util.Args;
36  
37  /**
38   * Common base class for decompressing {@link HttpEntity} implementations.
39   *
40   * @since 4.4
41   */
42  public class DecompressingEntity extends HttpEntityWrapper {
43  
44      /**
45       * Default buffer size.
46       */
47      private static final int BUFFER_SIZE = 1024 * 2;
48  
49      private final InputStreamFactory inputStreamFactory;
50  
51      /**
52       * {@link #getContent()} method must return the same {@link InputStream}
53       * instance when DecompressingEntity is wrapping a streaming entity.
54       */
55      private InputStream content;
56  
57      /**
58       * Constructs a new {@link DecompressingEntity}.
59       *
60       * @param wrapped the non-null {@link HttpEntity} to be wrapped
61       * @param inputStreamFactory factory to create decompressing stream.
62       */
63      public DecompressingEntity(
64              final HttpEntity wrapped,
65              final InputStreamFactory inputStreamFactory) {
66          super(wrapped);
67          this.inputStreamFactory = inputStreamFactory;
68      }
69  
70      private InputStream getDecompressingStream() throws IOException {
71          return new LazyDecompressingInputStream(super.getContent(), inputStreamFactory);
72      }
73  
74      @Override
75      public InputStream getContent() throws IOException {
76          if (super.isStreaming()) {
77              if (content == null) {
78                  content = getDecompressingStream();
79              }
80              return content;
81          }
82          return getDecompressingStream();
83      }
84  
85      @Override
86      public void writeTo(final OutputStream outStream) throws IOException {
87          Args.notNull(outStream, "Output stream");
88          try (InputStream inStream = getContent()) {
89              final byte[] buffer = new byte[BUFFER_SIZE];
90              int l;
91              while ((l = inStream.read(buffer)) != -1) {
92                  outStream.write(buffer, 0, l);
93              }
94          }
95      }
96  
97      @Override
98      public String getContentEncoding() {
99          /* Content encoding is now 'identity' */
100         return null;
101     }
102 
103     @Override
104     public long getContentLength() {
105         /* length of decompressed content is not known */
106         return -1;
107     }
108 
109 }