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1   /**
2    * Copyright (c) 2004-2011 QOS.ch
3    * All rights reserved.
4    *
5    * Permission is hereby granted, free  of charge, to any person obtaining
6    * a  copy  of this  software  and  associated  documentation files  (the
7    * "Software"), to  deal in  the Software without  restriction, including
8    * without limitation  the rights to  use, copy, modify,  merge, publish,
9    * distribute,  sublicense, and/or sell  copies of  the Software,  and to
10   * permit persons to whom the Software  is furnished to do so, subject to
11   * the following conditions:
12   *
13   * The  above  copyright  notice  and  this permission  notice  shall  be
14   * included in all copies or substantial portions of the Software.
15   *
16   * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
17   * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
18   * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
19   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21   * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
22   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23   *
24   */
25  package org.slf4j.migrator.helper;
26  
27  import java.util.Random;
28  
29  public class RandomHelper {
30  
31    private Random random = new Random(100);
32    final char folderSeparator;
33    
34    RandomHelper(char folderSeparator) {
35     this.folderSeparator = folderSeparator;
36    }
37    
38    private String randomString(int len) {
39      StringBuffer buf = new StringBuffer();
40      for (int i = 0; i < len; i++) {
41        int offset = random.nextInt(26);
42        char c = (char) ('a' + offset);
43        buf.append(c);
44      }
45      return buf.toString();
46    }
47  
48    int nextInt(int n) {
49      return random.nextInt(n);
50    }
51    
52    String buildRandomFileName(int averageNodeLength, int totalLength) {
53      StringBuffer buf = new StringBuffer();
54      int MAX_NODE_LENGTH = averageNodeLength * 2;
55      while (buf.length() < totalLength) {
56        int remaining = totalLength - buf.length();
57        int currentNodeLength;
58        if (remaining > MAX_NODE_LENGTH) {
59          currentNodeLength = random.nextInt(MAX_NODE_LENGTH) + 1;
60          buf.append(randomString(currentNodeLength));
61          buf.append('/');
62        } else {
63          currentNodeLength = remaining;
64          buf.append(randomString(currentNodeLength));
65        }
66      }
67      return buf.toString();
68    }
69  
70  }