blob: e9da7df1f3c60b83585ddb411d643859edcd6aa6 (
plain)
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
|
/*
* Copyright (C) 2007 Esmertec AG.
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed 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.
*/
package com.android.mmscommon.mms.pdu;
import java.io.ByteArrayOutputStream;
public class QuotedPrintable {
private static byte ESCAPE_CHAR = '=';
/**
* Decodes an array quoted-printable characters into an array of original bytes.
* Escaped characters are converted back to their original representation.
*
* <p>
* This function implements a subset of
* quoted-printable encoding specification (rule #1 and rule #2)
* as defined in RFC 1521.
* </p>
*
* @param bytes array of quoted-printable characters
* @return array of original bytes,
* null if quoted-printable decoding is unsuccessful.
*/
public static final byte[] decodeQuotedPrintable(byte[] bytes) {
if (bytes == null) {
return null;
}
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
for (int i = 0; i < bytes.length; i++) {
int b = bytes[i];
if (b == ESCAPE_CHAR) {
try {
if('\r' == (char)bytes[i + 1] &&
'\n' == (char)bytes[i + 2]) {
i += 2;
continue;
}
int u = Character.digit((char) bytes[++i], 16);
int l = Character.digit((char) bytes[++i], 16);
if (u == -1 || l == -1) {
return null;
}
buffer.write((char) ((u << 4) + l));
} catch (ArrayIndexOutOfBoundsException e) {
return null;
}
} else {
buffer.write(b);
}
}
return buffer.toByteArray();
}
}
|
