Java 在一个数轴上的多个连续区间内产生随机数

 1 public class Randomer {
 2 
 3     public static void main(String[] args) {
 4         Random rand = new Random();
 5         System.out.println(rand.nextInt(3)+1);
 6         
 7         int[] a = {1, 1, 1, 1, 4, 4, 4, 5, 5, 7, 7, 7, 9};
 8         int start = 0;
 9         int position;
10         for (int i = 0; i < a.length; i++) {
11             if (a[i] != a[start]) {
12                 position = getRandomBetweenAB(start, i);
13                 System.out.println(position + " : " + a[position]);
14                 start = i;
15             }
16         }
17         position = getRandomBetweenAB(start, a.length);
18         System.out.println(position + " : " + a[position]);
19     }
20     
21     private static int getRandomBetweenAB(int a, int b) {
22         Random rand = new Random();
23         return (rand.nextInt(b - a) + a);
24     }
25 }