生成第一个为零的随机数

public static void main (String[] args) throws java.lang.Exception
    {
        int x = -1;
        long seed = 0;
        int xxx = 100;
        while(x!=0){

            Random s = new Random(seed++);
            x = s.nextInt(xxx);

        }
        System.out.println("seed " + (seed-1) + " gives " + new Random(seed-1).nextInt(xxx));

    }

这将找到一个种子,对于给定的模数,下一个int将为零。(本例中恰好是18)。

无需破解随机类,只需编写自己的:

public class RandomGenerator {

    private int bound;
    private Random random;
    private boolean firstCall = true;

    public RandomGenerator(int bound, long seed) {
        this.bound = bound;
        random = new Random(seed)
    }

    public int next() {
        if (firstCall) {
            firstCall = false;
            return 0;
        }
        return random.nextInt(bound);
    }
}