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  }