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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       * {@link #getContent()} method must return the same {@link InputStream}
52       * instance when DecompressingEntity is wrapping a streaming entity.
53       */
54      private InputStream content;
55  
56      /**
57       * Creates a new {@link DecompressingEntity}.
58       *
59       * @param wrapped the non-null {@link HttpEntity} to be wrapped
60       * @param inputStreamFactory factory to create decompressing stream.
61       */
62      public DecompressingEntity(
63              final HttpEntity wrapped,
64              final InputStreamFactory inputStreamFactory) {
65          super(wrapped);
66          this.inputStreamFactory = inputStreamFactory;
67      }
68  
69      private InputStream getDecompressingStream() throws IOException {
70          return new LazyDecompressingInputStream(super.getContent(), inputStreamFactory);
71      }
72  
73      @Override
74      public InputStream getContent() throws IOException {
75          if (super.isStreaming()) {
76              if (content == null) {
77                  content = getDecompressingStream();
78              }
79              return content;
80          }
81          return getDecompressingStream();
82      }
83  
84      @Override
85      public void writeTo(final OutputStream outStream) throws IOException {
86          Args.notNull(outStream, "Output stream");
87          try (InputStream inStream = getContent()) {
88              final byte[] buffer = new byte[BUFFER_SIZE];
89              int l;
90              while ((l = inStream.read(buffer)) != -1) {
91                  outStream.write(buffer, 0, l);
92              }
93          }
94      }
95  
96      @Override
97      public String getContentEncoding() {
98          /* Content encoding is now 'identity' */
99          return null;
100     }
101 
102     @Override
103     public long getContentLength() {
104         /* length of decompressed content is not known */
105         return -1;
106     }
107 
108 }