1 /*
2 * ====================================================================
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * 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, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * ====================================================================
19 *
20 * This software consists of voluntary contributions made by many
21 * individuals on behalf of the Apache Software Foundation. For more
22 * information on the Apache Software Foundation, please see
23 * <http://www.apache.org/>.
24 *
25 */
26 package org.apache.http.client.entity;
27
28 import java.io.IOException;
29 import java.io.InputStream;
30 import java.io.OutputStream;
31
32 import org.apache.http.HttpEntity;
33 import org.apache.http.entity.HttpEntityWrapper;
34
35 /**
36 * Common base class for decompressing {@link HttpEntity} implementations.
37 *
38 * @since 4.1
39 */
40 abstract class DecompressingEntity extends HttpEntityWrapper {
41
42 /**
43 * Default buffer size.
44 */
45 private static final int BUFFER_SIZE = 1024 * 2;
46
47 /**
48 * {@link #getContent()} method must return the same {@link InputStream}
49 * instance when DecompressingEntity is wrapping a streaming entity.
50 */
51 private InputStream content;
52
53 /**
54 * Creates a new {@link DecompressingEntity}.
55 *
56 * @param wrapped
57 * the non-null {@link HttpEntity} to be wrapped
58 */
59 public DecompressingEntity(final HttpEntity wrapped) {
60 super(wrapped);
61 }
62
63 abstract InputStream decorate(final InputStream wrapped) throws IOException;
64
65 private InputStream getDecompressingStream() throws IOException {
66 InputStream in = wrappedEntity.getContent();
67 try {
68 return decorate(in);
69 } catch (IOException ex) {
70 in.close();
71 throw ex;
72 }
73 }
74
75 /**
76 * {@inheritDoc}
77 */
78 @Override
79 public InputStream getContent() throws IOException {
80 if (wrappedEntity.isStreaming()) {
81 if (content == null) {
82 content = getDecompressingStream();
83 }
84 return content;
85 } else {
86 return getDecompressingStream();
87 }
88 }
89
90 /**
91 * {@inheritDoc}
92 */
93 @Override
94 public void writeTo(OutputStream outstream) throws IOException {
95 if (outstream == null) {
96 throw new IllegalArgumentException("Output stream may not be null");
97 }
98 InputStream instream = getContent();
99 try {
100 byte[] buffer = new byte[BUFFER_SIZE];
101 int l;
102 while ((l = instream.read(buffer)) != -1) {
103 outstream.write(buffer, 0, l);
104 }
105 } finally {
106 instream.close();
107 }
108 }
109
110 }