1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * @(#)QPEncoderStream.java 1.6 02/03/27
28 */
29
30
31
32 package com.sun.xml.internal.messaging.saaj.packaging.mime.util;
33
34 import java.io.*;
35
36 /**
37 * This class implements a Quoted Printable Encoder. It is implemented as
38 * a FilterOutputStream, so one can just wrap this class around
39 * any output stream and write bytes into this filter. The Encoding
40 * is done as the bytes are written out.
41 *
42 * @author John Mani
43 */
44
45 public class QPEncoderStream extends FilterOutputStream {
46 private int count = 0; // number of bytes that have been output
47 private int bytesPerLine; // number of bytes per line
48 private boolean gotSpace = false;
49 private boolean gotCR = false;
50
51 /**
52 * Create a QP encoder that encodes the specified input stream
53 * @param out the output stream
54 * @param bytesPerLine the number of bytes per line. The encoder
55 * inserts a CRLF sequence after this many number
56 * of bytes.
57 */
58 public QPEncoderStream(OutputStream out, int bytesPerLine) {
59 super(out);
60 // Subtract 1 to account for the '=' in the soft-return
61 // at the end of a line
62 this.bytesPerLine = bytesPerLine - 1;
63 }
64
65 /**
66 * Create a QP encoder that encodes the specified input stream.
67 * Inserts the CRLF sequence after outputting 76 bytes.
68 * @param out the output stream
69 */
70 public QPEncoderStream(OutputStream out) {
71 this(out, 76);
72 }
73
74 /**
75 * Encodes <code>len</code> bytes from the specified
76 * <code>byte</code> array starting at offset <code>off</code> to
77 * this output stream.
78 *
79 * @param b the data.
80 * @param off the start offset in the data.
81 * @param len the number of bytes to write.
82 * @exception IOException if an I/O error occurs.
83 */
84 @Override
85 public void write(byte[] b, int off, int len) throws IOException {
86 for (int i = 0; i < len; i++)
87 write(b[off + i]);
88 }
89
90 /**
91 * Encodes <code>b.length</code> bytes to this output stream.
92 * @param b the data to be written.
93 * @exception IOException if an I/O error occurs.
94 */
95 @Override
96 public void write(byte[] b) throws IOException {
97 write(b, 0, b.length);
98 }
99
100 /**
101 * Encodes the specified <code>byte</code> to this output stream.
102 * @param c the <code>byte</code>.
103 * @exception IOException if an I/O error occurs.
104 */
105 @Override
106 public void write(int c) throws IOException {
107 c = c & 0xff; // Turn off the MSB.
108 if (gotSpace) { // previous character was <SPACE>
109 if (c == '\r' || c == '\n')
110 // if CR/LF, we need to encode the <SPACE> char
111 output(' ', true);
112 else // no encoding required, just output the char
113 output(' ', false);
114 gotSpace = false;
115 }
116
117 if (c == '\r') {
118 gotCR = true;
119 outputCRLF();
120 } else {
121 if (c == '\n') {
122 if (gotCR)
123 // This is a CRLF sequence, we already output the
124 // corresponding CRLF when we got the CR, so ignore this
125 ;
126 else
127 outputCRLF();
128 } else if (c == ' ') {
129 gotSpace = true;
130 } else if (c < 040 || c >= 0177 || c == '=')
131 // Encoding required.
132 output(c, true);
133 else // No encoding required
134 output(c, false);
135 // whatever it was, it wasn't a CR
136 gotCR = false;
137 }
138 }
139
140 /**
141 * Flushes this output stream and forces any buffered output bytes
142 * to be encoded out to the stream.
143 * @exception IOException if an I/O error occurs.
144 */
145 @Override
146 public void flush() throws IOException {
147 out.flush();
148 }
149
150 /**
151 * Forces any buffered output bytes to be encoded out to the stream
152 * and closes this output stream
153 */
154 @Override
155 public void close() throws IOException {
156 out.close();
157 }
158
159 private void outputCRLF() throws IOException {
160 out.write('\r');
161 out.write('\n');
162 count = 0;
163 }
164
165 // The encoding table
166 private final static char hex[] = {
167 '0','1', '2', '3', '4', '5', '6', '7',
168 '8','9', 'A', 'B', 'C', 'D', 'E', 'F'
169 };
170
171 protected void output(int c, boolean encode) throws IOException {
172 if (encode) {
173 if ((count += 3) > bytesPerLine) {
174 out.write('=');
175 out.write('\r');
176 out.write('\n');
177 count = 3; // set the next line's length
178 }
179 out.write('=');
180 out.write(hex[c >> 4]);
181 out.write(hex[c & 0xf]);
182 } else {
183 if (++count > bytesPerLine) {
184 out.write('=');
185 out.write('\r');
186 out.write('\n');
187 count = 1; // set the next line's length
188 }
189 out.write(c);
190 }
191 }
192
193 /**** begin TEST program ***
194 public static void main(String argv[]) throws Exception {
195 FileInputStream infile = new FileInputStream(argv[0]);
196 QPEncoderStream encoder = new QPEncoderStream(System.out);
197 int c;
198
199 while ((c = infile.read()) != -1)
200 encoder.write(c);
201 encoder.close();
202 }
203 *** end TEST program ***/
204 }