1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/entity/BufferedHttpEntity.java $
3 * $Revision: 496070 $
4 * $Date: 2007-01-14 04:18:34 -0800 (Sun, 14 Jan 2007) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.entity;
33
34import java.io.ByteArrayInputStream;
35import java.io.IOException;
36import java.io.InputStream;
37import java.io.OutputStream;
38
39import org.apache.http.HttpEntity;
40import org.apache.http.util.EntityUtils;
41
42/**
43 * A wrapping entity that buffers it content if necessary.
44 * The buffered entity is always repeatable.
45 * If the wrapped entity is repeatable itself, calls are passed through.
46 * If the wrapped entity is not repeatable, the content is read into a
47 * buffer once and provided from there as often as required.
48 *
49 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
50 *
51 * @version $Revision: 496070 $
52 *
53 * @since 4.0
54 */
55public class BufferedHttpEntity extends HttpEntityWrapper {
56
57    private final byte[] buffer;
58
59    public BufferedHttpEntity(final HttpEntity entity) throws IOException {
60        super(entity);
61        if (!entity.isRepeatable() || entity.getContentLength() < 0) {
62            this.buffer = EntityUtils.toByteArray(entity);
63        } else {
64            this.buffer = null;
65        }
66    }
67
68    public long getContentLength() {
69        if (this.buffer != null) {
70            return this.buffer.length;
71        } else {
72            return wrappedEntity.getContentLength();
73        }
74    }
75
76    public InputStream getContent() throws IOException {
77        if (this.buffer != null) {
78            return new ByteArrayInputStream(this.buffer);
79        } else {
80            return wrappedEntity.getContent();
81        }
82    }
83
84    /**
85     * Tells that this entity does not have to be chunked.
86     *
87     * @return  <code>false</code>
88     */
89    public boolean isChunked() {
90        return (buffer == null) && wrappedEntity.isChunked();
91    }
92
93    /**
94     * Tells that this entity is repeatable.
95     *
96     * @return  <code>true</code>
97     */
98    public boolean isRepeatable() {
99        return true;
100    }
101
102
103    public void writeTo(final OutputStream outstream) throws IOException {
104        if (outstream == null) {
105            throw new IllegalArgumentException("Output stream may not be null");
106        }
107        if (this.buffer != null) {
108            outstream.write(this.buffer);
109        } else {
110            wrappedEntity.writeTo(outstream);
111        }
112    }
113
114
115    // non-javadoc, see interface HttpEntity
116    public boolean isStreaming() {
117        return (buffer == null) && wrappedEntity.isStreaming();
118    }
119
120} // class BufferedHttpEntity
121