1 /* |
|
2 * Copyright (c) 1997, 2013, 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 * @(#)QPDecoderStream.java 1.9 02/04/02 |
|
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 QP Decoder. It is implemented as |
|
38 * a FilterInputStream, so one can just wrap this class around |
|
39 * any input stream and read bytes from this filter. The decoding |
|
40 * is done as the bytes are read out. |
|
41 * |
|
42 * @author John Mani |
|
43 */ |
|
44 |
|
45 public class QPDecoderStream extends FilterInputStream { |
|
46 protected byte[] ba = new byte[2]; |
|
47 protected int spaces = 0; |
|
48 |
|
49 /** |
|
50 * Create a Quoted Printable decoder that decodes the specified |
|
51 * input stream. |
|
52 * @param in the input stream |
|
53 */ |
|
54 public QPDecoderStream(InputStream in) { |
|
55 super(new PushbackInputStream(in, 2)); // pushback of size=2 |
|
56 } |
|
57 |
|
58 /** |
|
59 * Read the next decoded byte from this input stream. The byte |
|
60 * is returned as an <code>int</code> in the range <code>0</code> |
|
61 * to <code>255</code>. If no byte is available because the end of |
|
62 * the stream has been reached, the value <code>-1</code> is returned. |
|
63 * This method blocks until input data is available, the end of the |
|
64 * stream is detected, or an exception is thrown. |
|
65 * |
|
66 * @return the next byte of data, or <code>-1</code> if the end of the |
|
67 * stream is reached. |
|
68 * @exception IOException if an I/O error occurs. |
|
69 */ |
|
70 public int read() throws IOException { |
|
71 if (spaces > 0) { |
|
72 // We have cached space characters, return one |
|
73 spaces--; |
|
74 return ' '; |
|
75 } |
|
76 |
|
77 int c = in.read(); |
|
78 |
|
79 if (c == ' ') { |
|
80 // Got space, keep reading till we get a non-space char |
|
81 while ((c = in.read()) == ' ') |
|
82 spaces++; |
|
83 |
|
84 if (c == '\r' || c == '\n' || c == -1) |
|
85 // If the non-space char is CR/LF/EOF, the spaces we got |
|
86 // so far is junk introduced during transport. Junk 'em. |
|
87 spaces = 0; |
|
88 else { |
|
89 // The non-space char is NOT CR/LF, the spaces are valid. |
|
90 ((PushbackInputStream)in).unread(c); |
|
91 c = ' '; |
|
92 } |
|
93 return c; // return either <SPACE> or <CR/LF> |
|
94 } |
|
95 else if (c == '=') { |
|
96 // QP Encoded atom. Decode the next two bytes |
|
97 int a = in.read(); |
|
98 |
|
99 if (a == '\n') { |
|
100 /* Hmm ... not really confirming QP encoding, but lets |
|
101 * allow this as a LF terminated encoded line .. and |
|
102 * consider this a soft linebreak and recurse to fetch |
|
103 * the next char. |
|
104 */ |
|
105 return read(); |
|
106 } else if (a == '\r') { |
|
107 // Expecting LF. This forms a soft linebreak to be ignored. |
|
108 int b = in.read(); |
|
109 if (b != '\n') |
|
110 /* Not really confirming QP encoding, but |
|
111 * lets allow this as well. |
|
112 */ |
|
113 ((PushbackInputStream)in).unread(b); |
|
114 return read(); |
|
115 } else if (a == -1) { |
|
116 // Not valid QP encoding, but we be nice and tolerant here ! |
|
117 return -1; |
|
118 } else { |
|
119 ba[0] = (byte)a; |
|
120 ba[1] = (byte)in.read(); |
|
121 try { |
|
122 return ASCIIUtility.parseInt(ba, 0, 2, 16); |
|
123 } catch (NumberFormatException nex) { |
|
124 /* |
|
125 System.err.println( |
|
126 "Illegal characters in QP encoded stream: " + |
|
127 ASCIIUtility.toString(ba, 0, 2) |
|
128 ); |
|
129 */ |
|
130 |
|
131 ((PushbackInputStream)in).unread(ba); |
|
132 return c; |
|
133 } |
|
134 } |
|
135 } |
|
136 return c; |
|
137 } |
|
138 |
|
139 /** |
|
140 * Reads up to <code>len</code> decoded bytes of data from this input stream |
|
141 * into an array of bytes. This method blocks until some input is |
|
142 * available. |
|
143 * <p> |
|
144 * |
|
145 * @param buf the buffer into which the data is read. |
|
146 * @param off the start offset of the data. |
|
147 * @param len the maximum number of bytes read. |
|
148 * @return the total number of bytes read into the buffer, or |
|
149 * <code>-1</code> if there is no more data because the end of |
|
150 * the stream has been reached. |
|
151 * @exception IOException if an I/O error occurs. |
|
152 */ |
|
153 public int read(byte[] buf, int off, int len) throws IOException { |
|
154 int i, c; |
|
155 for (i = 0; i < len; i++) { |
|
156 if ((c = read()) == -1) { |
|
157 if (i == 0) // At end of stream, so we should |
|
158 i = -1; // return -1 , NOT 0. |
|
159 break; |
|
160 } |
|
161 buf[off+i] = (byte)c; |
|
162 } |
|
163 return i; |
|
164 } |
|
165 |
|
166 /** |
|
167 * Tests if this input stream supports marks. Currently this class |
|
168 * does not support marks |
|
169 */ |
|
170 public boolean markSupported() { |
|
171 return false; |
|
172 } |
|
173 |
|
174 /** |
|
175 * Returns the number of bytes that can be read from this input |
|
176 * stream without blocking. The QP algorithm does not permit |
|
177 * a priori knowledge of the number of bytes after decoding, so |
|
178 * this method just invokes the <code>available</code> method |
|
179 * of the original input stream. |
|
180 */ |
|
181 public int available() throws IOException { |
|
182 // This is bogus ! We don't really know how much |
|
183 // bytes are available *after* decoding |
|
184 return in.available(); |
|
185 } |
|
186 |
|
187 /**** begin TEST program |
|
188 public static void main(String argv[]) throws Exception { |
|
189 FileInputStream infile = new FileInputStream(argv[0]); |
|
190 QPDecoderStream decoder = new QPDecoderStream(infile); |
|
191 int c; |
|
192 |
|
193 while ((c = decoder.read()) != -1) |
|
194 System.out.print((char)c); |
|
195 System.out.println(); |
|
196 } |
|
197 *** end TEST program ****/ |
|
198 } |
|