org.argeo.app.api/src/org/argeo/app/api/IdRange.java

   1 package org.argeo.app.api;
   2
   3 /** A range of numerical IDs (typically numerical uid or gid). */
   4 public class IdRange {
   5
   6         private final long min;
   7         private final long max;
   8
   9         public IdRange(long min, long max) {
  10                 this.min = min;
  11                 this.max = max;
  12         }
  13
  14         public IdRange(long minPow10) {
  15                 this(minPow10, maxFromMinPow10(minPow10));
  16         }
  17
  18         public long getMin() {
  19                 return min;
  20         }
  21
  22         public long getMax() {
  23                 return max;
  24         }
  25
  26         private static long maxFromMinPow10(long minPow10) {
  27                 if ((minPow10 % 100) != 0) {
  28                         throw new IllegalArgumentException(minPow10 + " must at least ends with two zeroes");
  29                 }
  30                 int exp = 2;
  31                 exp: for (int i = exp + 1; i < 10; i++) {
  32                         if ((minPow10 % pow10(i)) != 0)
  33                                 break exp;
  34                         exp++;
  35                 }
  36                 System.out.println(exp);
  37
  38                 long max = minPow10 + pow10(exp) - 1;
  39                 return max;
  40         }
  41
  42         /** Power of 10. */
  43         private static long pow10(int exp) {
  44                 if (exp == 0)
  45                         return 1;
  46                 else
  47                         return 10 * pow10(exp - 1);
  48         }
  49
  50         public static void main(String... args) {
  51                 System.out.println(maxFromMinPow10(100));
  52                 System.out.println(maxFromMinPow10(78500));
  53                 System.out.println(maxFromMinPow10(716850000));
  54
  55 //              System.out.println(pow10(6));
  56 //              System.out.println(maxFromMinPow10(12));
  57 //              System.out.println(maxFromMinPow10(124));
  58 //              System.out.println(maxFromMinPow10(99814565));
  59         }
  60 }