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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          StringBuilder buf = new StringBuilder();
    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          StringBuilder buf = new StringBuilder();
    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  }