| Scrambler.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 * The contents of this file are subject to the terms of the Liferay Enterprise
5 * Subscription License ("License"). You may not use this file except in
6 * compliance with the License. You can obtain a copy of the License by
7 * contacting Liferay, Inc. See the License for the specific language governing
8 * permissions and limitations under the License, including but not limited to
9 * distribution rights of the Software.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
12 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
14 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
15 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 */
19
20 package com.liferay.portlet.words.util;
21
22 import com.liferay.portlet.words.ScramblerException;
23 import com.liferay.portlet.words.util.comparator.WordComparator;
24
25 import java.util.Set;
26 import java.util.TreeSet;
27
28 /**
29 * <a href="Scrambler.java.html"><b><i>View Source</i></b></a>
30 *
31 * @author Brian Wing Shun Chan
32 *
33 */
34 public class Scrambler {
35
36 public Scrambler(String word) throws ScramblerException {
37 if (word == null || word.length() < 3) {
38 throw new ScramblerException();
39 }
40
41 _word = word;
42 _words = new TreeSet<String>(new WordComparator());
43 }
44
45 public String[] scramble() {
46 if (_word == null) {
47 return new String[0];
48 }
49
50 _scramble(0, _word.length(), _word.toCharArray());
51
52 return _words.toArray(new String[_words.size()]);
53 }
54
55 private void _rotate(char[] charArray, int start) {
56 char temp = charArray[start];
57
58 for (int i = charArray.length - start -1; i > 0; i--) {
59 charArray[start] = charArray[++start];
60 }
61
62 charArray[start] = temp;
63 }
64
65 private void _scramble(int start, int length, char[] charArray) {
66 if (length == 0) {
67 String word = new String(charArray);
68
69 for (int i = 3; i <= charArray.length; i++) {
70 _words.add(word.substring(0, i));
71 }
72 }
73 else {
74 for (int i = 0; i < length; i++) {
75 _scramble(start + 1, length - 1, charArray);
76 _rotate(charArray, start);
77 }
78 }
79 }
80
81 private String _word;
82 private Set<String> _words;
83
84 }