| Scrambler.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 * SOFTWARE.
21 */
22
23 package com.liferay.portlet.words.util;
24
25 import com.liferay.portlet.words.ScramblerException;
26 import com.liferay.portlet.words.util.comparator.WordComparator;
27
28 import java.util.Set;
29 import java.util.TreeSet;
30
31 /**
32 * <a href="Scrambler.java.html"><b><i>View Source</i></b></a>
33 *
34 * @author Brian Wing Shun Chan
35 *
36 */
37 public class Scrambler {
38
39 public Scrambler(String word) throws ScramblerException {
40 if (word == null || word.length() < 3) {
41 throw new ScramblerException();
42 }
43
44 _word = word;
45 _words = new TreeSet<String>(new WordComparator());
46 }
47
48 public String[] scramble() {
49 if (_word == null) {
50 return new String[0];
51 }
52
53 _scramble(0, _word.length(), _word.toCharArray());
54
55 return _words.toArray(new String[_words.size()]);
56 }
57
58 private void _rotate(char[] charArray, int start) {
59 char temp = charArray[start];
60
61 for (int i = charArray.length - start -1; i > 0; i--) {
62 charArray[start] = charArray[++start];
63 }
64
65 charArray[start] = temp;
66 }
67
68 private void _scramble(int start, int length, char[] charArray) {
69 if (length == 0) {
70 String word = new String(charArray);
71
72 for (int i = 3; i <= charArray.length; i++) {
73 _words.add(word.substring(0, i));
74 }
75 }
76 else {
77 for (int i = 0; i < length; i++) {
78 _scramble(start + 1, length - 1, charArray);
79 _rotate(charArray, start);
80 }
81 }
82 }
83
84 private String _word;
85 private Set<String> _words;
86
87 }