关于 Java 的 util 中随机数的问题

最近看 java 的时候，碰到了一个问题，代码如下：

package com.company;

import java.util.Random;

public class Main {
    final static int MAX = 100;
    final static int MIN = 10;

    public static int gcd(int p, int q) {
        return (q == 0) ? p : gcd(q, p % q);
    }

    public static void main(String[] args) {
        // write your code here
        int p, q;
        Random r = new Random();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++) {
            p = r.nextInt(MAX) % (MAX - MIN + 1) + MIN;
            q = r.nextInt(MAX) % (MAX - MIN + 1) + MIN;
            while (p == q) {
                System.out.println("hit - " + p + ", " + q);
                q = r.nextInt(MAX) % (MAX - MIN + 1) + MIN;
            }
            sb.append("GCD of " + p + " and " + q + " is " + gcd(p, q));
            sb.append(System.getProperty("line.separator"));
        }
        System.out.println(sb);
        return;
    }
}

输出结果是:
hit - 15, 15
GCD of 31 and 30 is 1
GCD of 15 and 48 is 3
GCD of 78 and 44 is 2
GCD of 89 and 18 is 1
GCD of 60 and 17 is 1
GCD of 86 and 59 is 1
GCD of 73 and 18 is 1
GCD of 22 and 84 is 2
GCD of 75 and 66 is 3
GCD of 99 and 46 is 1

这里有一个问题,我本来的意思是,当 q 取到与 p 一样的随机值时,重取一次,直到与 p 不一致为止.在实际代码运行中,当 p 为 15 的时候,p 应该不重新取值,q 重新取值,第一次 hit 的时候,p 应该是保持 15,而 q 是新的随机值.但是执行结果却不是这样的,请问一下问题出在哪里?