1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/ChunkedOutputStream.java $
* $Revision: 645081 $
* $Date: 2008-04-05 04:36:42 -0700 (Sat, 05 Apr 2008) $
*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.impl.io;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.http.io.SessionOutputBuffer;
/**
* Implements chunked transfer coding.
* See <a href="http://www.w3.org/Protocols/rfc2616/rfc2616.txt">RFC 2616</a>,
* <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.6">section 3.6.1</a>.
* Writes are buffered to an internal buffer (2048 default size).
*
* @author Mohammad Rezaei (Goldman, Sachs & Co.)
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*
* @since 4.0
*/
public class ChunkedOutputStream extends OutputStream {
// ----------------------------------------------------- Instance Variables
private final SessionOutputBuffer out;
private byte[] cache;
private int cachePosition = 0;
private boolean wroteLastChunk = false;
/** True if the stream is closed. */
private boolean closed = false;
// ----------------------------------------------------------- Constructors
/**
* Wraps a session output buffer and chunks the output.
* @param out the session output buffer to wrap
* @param bufferSize minimum chunk size (excluding last chunk)
* @throws IOException
*/
public ChunkedOutputStream(final SessionOutputBuffer out, int bufferSize)
throws IOException {
super();
this.cache = new byte[bufferSize];
this.out = out;
}
/**
* Wraps a session output buffer and chunks the output. The default buffer
* size of 2048 was chosen because the chunk overhead is less than 0.5%
*
* @param out the output buffer to wrap
* @throws IOException
*/
public ChunkedOutputStream(final SessionOutputBuffer out)
throws IOException {
this(out, 2048);
}
// ----------------------------------------------------------- Internal methods
/**
* Writes the cache out onto the underlying stream
* @throws IOException
*/
protected void flushCache() throws IOException {
if (this.cachePosition > 0) {
this.out.writeLine(Integer.toHexString(this.cachePosition));
this.out.write(this.cache, 0, this.cachePosition);
this.out.writeLine("");
this.cachePosition = 0;
}
}
/**
* Writes the cache and bufferToAppend to the underlying stream
* as one large chunk
* @param bufferToAppend
* @param off
* @param len
* @throws IOException
*/
protected void flushCacheWithAppend(byte bufferToAppend[], int off, int len) throws IOException {
this.out.writeLine(Integer.toHexString(this.cachePosition + len));
this.out.write(this.cache, 0, this.cachePosition);
this.out.write(bufferToAppend, off, len);
this.out.writeLine("");
this.cachePosition = 0;
}
protected void writeClosingChunk() throws IOException {
// Write the final chunk.
this.out.writeLine("0");
this.out.writeLine("");
}
// ----------------------------------------------------------- Public Methods
/**
* Must be called to ensure the internal cache is flushed and the closing chunk is written.
* @throws IOException
*/
public void finish() throws IOException {
if (!this.wroteLastChunk) {
flushCache();
writeClosingChunk();
this.wroteLastChunk = true;
}
}
// -------------------------------------------- OutputStream Methods
public void write(int b) throws IOException {
if (this.closed) {
throw new IOException("Attempted write to closed stream.");
}
this.cache[this.cachePosition] = (byte) b;
this.cachePosition++;
if (this.cachePosition == this.cache.length) flushCache();
}
/**
* Writes the array. If the array does not fit within the buffer, it is
* not split, but rather written out as one large chunk.
* @param b
* @throws IOException
*/
public void write(byte b[]) throws IOException {
write(b, 0, b.length);
}
public void write(byte src[], int off, int len) throws IOException {
if (this.closed) {
throw new IOException("Attempted write to closed stream.");
}
if (len >= this.cache.length - this.cachePosition) {
flushCacheWithAppend(src, off, len);
} else {
System.arraycopy(src, off, cache, this.cachePosition, len);
this.cachePosition += len;
}
}
/**
* Flushes the content buffer and the underlying stream.
* @throws IOException
*/
public void flush() throws IOException {
flushCache();
this.out.flush();
}
/**
* Finishes writing to the underlying stream, but does NOT close the underlying stream.
* @throws IOException
*/
public void close() throws IOException {
if (!this.closed) {
this.closed = true;
finish();
this.out.flush();
}
}
}
|
