Source code: org/apache/http/impl/io/AbstractHttpDataTransmitter.java
1 /*
2 * $HeadURL: https://svn.apache.org/repos/asf/jakarta/httpcomponents/httpcore/tags/4.0-alpha2/src/java/org/apache/http/impl/io/AbstractHttpDataTransmitter.java $
3 * $Revision: 390877 $
4 * $Date: 2006-04-02 20:12:59 +0200 (Sun, 02 Apr 2006) $
5 *
6 * ====================================================================
7 *
8 * Copyright 2002-2004 The Apache Software Foundation
9 *
10 * Licensed under the Apache License, Version 2.0 (the "License");
11 * you may not use this file except in compliance with the License.
12 * You may obtain a copy of the License at
13 *
14 * http://www.apache.org/licenses/LICENSE-2.0
15 *
16 * Unless required by applicable law or agreed to in writing, software
17 * distributed under the License is distributed on an "AS IS" BASIS,
18 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 * See the License for the specific language governing permissions and
20 * limitations under the License.
21 * ====================================================================
22 *
23 * This software consists of voluntary contributions made by many
24 * individuals on behalf of the Apache Software Foundation. For more
25 * information on the Apache Software Foundation, please see
26 * <http://www.apache.org/>.
27 *
28 */
29
30 package org.apache.http.impl.io;
31
32 import java.io.IOException;
33 import java.io.OutputStream;
34
35 import org.apache.http.io.ByteArrayBuffer;
36 import org.apache.http.io.CharArrayBuffer;
37 import org.apache.http.io.HttpDataTransmitter;
38 import org.apache.http.params.HttpParams;
39 import org.apache.http.params.HttpProtocolParams;
40 import org.apache.http.protocol.HTTP;
41
42 /**
43 * Abstract base class for data transmitters using traditional IO.
44 *
45 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
46 *
47 */
48 public abstract class AbstractHttpDataTransmitter implements HttpDataTransmitter {
49
50 private static final byte[] CRLF = new byte[] {HTTP.CR, HTTP.LF};
51
52 private static int MAX_CHUNK = 256;
53
54 private OutputStream outstream;
55 private ByteArrayBuffer buffer;
56
57 private String charset = HTTP.US_ASCII;
58 private boolean ascii = true;
59
60 protected void init(final OutputStream outstream, int buffersize) {
61 if (outstream == null) {
62 throw new IllegalArgumentException("Input stream may not be null");
63 }
64 if (buffersize <= 0) {
65 throw new IllegalArgumentException("Buffer size may not be negative or zero");
66 }
67 this.outstream = outstream;
68 this.buffer = new ByteArrayBuffer(buffersize);
69 }
70
71 protected void flushBuffer() throws IOException {
72 if (this.buffer.length() > 0) {
73 this.outstream.write(this.buffer.buffer(), 0, this.buffer.length());
74 this.buffer.clear();
75 }
76 }
77
78 public void flush() throws IOException {
79 flushBuffer();
80 this.outstream.flush();
81 }
82
83 public void write(final byte[] b, int off, int len) throws IOException {
84 if (b == null) {
85 return;
86 }
87 // Do not want to buffer largish chunks
88 // if the byte array is larger then MAX_CHUNK
89 // write it directly to the output stream
90 if (len > MAX_CHUNK || len > this.buffer.capacity()) {
91 // flush the buffer
92 flushBuffer();
93 // write directly to the out stream
94 this.outstream.write(b, off, len);
95 } else {
96 // Do not let the buffer grow unnecessarily
97 int freecapacity = this.buffer.capacity() - this.buffer.length();
98 if (len > freecapacity) {
99 // flush the buffer
100 flushBuffer();
101 }
102 // buffer
103 this.buffer.append(b, off, len);
104 }
105 }
106
107 public void write(final byte[] b) throws IOException {
108 if (b == null) {
109 return;
110 }
111 write(b, 0, b.length);
112 }
113
114 public void write(int b) throws IOException {
115 if (this.buffer.isFull()) {
116 flushBuffer();
117 }
118 this.buffer.append(b);
119 }
120
121 public void writeLine(final String s) throws IOException {
122 if (s == null) {
123 return;
124 }
125 if (s.length() > 0) {
126 write(s.getBytes(this.charset));
127 }
128 write(CRLF);
129 }
130
131 public void writeLine(final CharArrayBuffer s) throws IOException {
132 if (s == null) {
133 return;
134 }
135 if (this.ascii) {
136 int off = 0;
137 int remaining = s.length();
138 while (remaining > 0) {
139 int chunk = this.buffer.capacity() - this.buffer.length();
140 chunk = Math.min(chunk, remaining);
141 if (chunk > 0) {
142 this.buffer.append(s, off, chunk);
143 }
144 if (this.buffer.isFull()) {
145 flushBuffer();
146 }
147 off += chunk;
148 remaining -= chunk;
149 }
150 } else {
151 // This is VERY memory inefficient, BUT since non-ASCII charsets are
152 // NOT meant to be used anyway, there's no point optimizing it
153 byte[] tmp = s.toString().getBytes(this.charset);
154 write(tmp);
155 }
156 write(CRLF);
157 }
158
159 public void reset(final HttpParams params) {
160 this.charset = HttpProtocolParams.getHttpElementCharset(params);
161 this.ascii = this.charset.equalsIgnoreCase(HTTP.US_ASCII)
162 || this.charset.equalsIgnoreCase(HTTP.ASCII);
163 }
164
165 }