| Scrambler.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 *
5 *
6 *
7 * The contents of this file are subject to the terms of the Liferay Enterprise
8 * Subscription License ("License"). You may not use this file except in
9 * compliance with the License. You can obtain a copy of the License by
10 * contacting Liferay, Inc. See the License for the specific language governing
11 * permissions and limitations under the License, including but not limited to
12 * distribution rights 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 public class Scrambler {
37
38 public Scrambler(String word) throws ScramblerException {
39 if (word == null || word.length() < 3) {
40 throw new ScramblerException();
41 }
42
43 _word = word;
44 _words = new TreeSet<String>(new WordComparator());
45 }
46
47 public String[] scramble() {
48 if (_word == null) {
49 return new String[0];
50 }
51
52 _scramble(0, _word.length(), _word.toCharArray());
53
54 return _words.toArray(new String[_words.size()]);
55 }
56
57 private void _rotate(char[] charArray, int start) {
58 char temp = charArray[start];
59
60 for (int i = charArray.length - start -1; i > 0; i--) {
61 charArray[start] = charArray[++start];
62 }
63
64 charArray[start] = temp;
65 }
66
67 private void _scramble(int start, int length, char[] charArray) {
68 if (length == 0) {
69 String word = new String(charArray);
70
71 for (int i = 3; i <= charArray.length; i++) {
72 _words.add(word.substring(0, i));
73 }
74 }
75 else {
76 for (int i = 0; i < length; i++) {
77 _scramble(start + 1, length - 1, charArray);
78 _rotate(charArray, start);
79 }
80 }
81 }
82
83 private String _word;
84 private Set<String> _words;
85
86 }