1 /* ====================================================================
2 * Copyright (c) 2006 J.T. Beetstra
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 * ====================================================================
23 */
24 package com.beetstra.jutf7;
25
26
27 /**
28 * <p>The character set specified in RFC 3501 to use for IMAP4rev1 mailbox name encoding.</p>
29 *
30 * @see <a href="http://tools.ietf.org/html/rfc3501">RFC 3501</a>
31 * @author Jaap Beetstra
32 */
33 class ModifiedUTF7Charset extends UTF7StyleCharset {
34 private static final String MODIFIED_BASE64_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
35 + "abcdefghijklmnopqrstuvwxyz" + "0123456789+,";
36
37 ModifiedUTF7Charset(String name, String[] aliases) {
38 super(name, aliases, MODIFIED_BASE64_ALPHABET, true);
39 }
40
41 boolean canEncodeDirectly(char ch) {
42 if (ch == shift())
43 return false;
44 return ch >= 0x20 && ch <= 0x7E;
45 }
46
47 byte shift() {
48 return '&';
49 }
50
51 byte unshift() {
52 return '-';
53 }
54 }