1 /**
2 * Copyright 2005-2011 The Kuali Foundation
3 *
4 * Licensed under the Educational Community License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.opensource.org/licenses/ecl2.php
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.kuali.rice.kim.sesn;
17
18 import java.security.SecureRandom;
19
20 /**
21 * This class generates a random string for creating Distributed Session Tickets
22 *
23 * @author Kuali Rice Team (rice.collab@kuali.org)
24 *
25 */
26 public class SessionIdGenerator {
27
28 /** The array of printable characters to be used in our random string. */
29 private static final char[] PRINTABLE_CHARACTERS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ012345679"
30 .toCharArray();
31
32 private static final SecureRandom randomizer = new SecureRandom();
33
34 public static String getNewString() {
35 final byte[] random = getNewStringAsBytes();
36
37 return convertBytesToString(random);
38 }
39
40
41 private static byte[] getNewStringAsBytes() {
42 final byte[] random = new byte[40];
43
44 randomizer.nextBytes(random);
45
46 return random;
47 }
48
49 private static String convertBytesToString(final byte[] random) {
50 final char[] output = new char[random.length];
51 for (int i = 0; i < random.length; i++) {
52 final int index = Math.abs(random[i] % PRINTABLE_CHARACTERS.length);
53 output[i] = PRINTABLE_CHARACTERS[index];
54 }
55
56 return new String(output);
57 }
58 }