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.entity;
28
29 import java.io.IOException;
30 import java.io.InputStream;
31 import java.io.OutputStream;
32
33 import org.apache.http.Header;
34 import org.apache.http.HttpEntity;
35 import org.apache.http.entity.HttpEntityWrapper;
36 import org.apache.http.util.Args;
37
38 /**
39 * Common base class for decompressing {@link HttpEntity} implementations.
40 *
41 * @since 4.4
42 */
43 public class DecompressingEntity extends HttpEntityWrapper {
44
45 /**
46 * Default buffer size.
47 */
48 private static final int BUFFER_SIZE = 1024 * 2;
49
50 private final InputStreamFactory inputStreamFactory;
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 * Creates 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 final InputStream in = wrappedEntity.getContent();
72 return new LazyDecompressingInputStream(in, inputStreamFactory);
73 }
74
75 @Override
76 public InputStream getContent() throws IOException {
77 if (wrappedEntity.isStreaming()) {
78 if (content == null) {
79 content = getDecompressingStream();
80 }
81 return content;
82 }
83 return getDecompressingStream();
84 }
85
86 @Override
87 public void writeTo(final OutputStream outStream) throws IOException {
88 Args.notNull(outStream, "Output stream");
89 final InputStream inStream = getContent();
90 try {
91 final byte[] buffer = new byte[BUFFER_SIZE];
92 int l;
93 while ((l = inStream.read(buffer)) != -1) {
94 outStream.write(buffer, 0, l);
95 }
96 } finally {
97 inStream.close();
98 }
99 }
100
101 @Override
102 public Header getContentEncoding() {
103 /* Content encoding is now 'identity' */
104 return null;
105 }
106
107 @Override
108 public long getContentLength() {
109 /* length of decompressed content is not known */
110 return -1;
111 }
112
113 }