Why does this random generator return the same result over and over?

Question

I wrote this to generate random Candidate objects to fill the ArrayList pop . Each Candidate holds an array, and this code its supposed to generate a different array for each Candidate :

ArrayList<Candidate> pop = new ArrayList<>();
int skinThicknes, attackDamage ,skinCoulor, canFly, canSwing, speed, flySpeed, swingSpeed, num = 0;
Random rnd;
rnd = new Random();
while(num < size) {

    skinThicknes = rnd.nextInt(101);
    attackDamage = rnd.nextInt(101);
    skinCoulor = rnd.nextInt(3);
    canFly = rnd.nextInt(1);
    canSwing = rnd.nextInt(1);
    speed = rnd.nextInt(1001);
    flySpeed = rnd.nextInt(1001);
    swingSpeed = rnd.nextInt(1001);
    if(canFly == 0){flySpeed = 0;}
    if(canSwing == 0){swingSpeed  = 0;}
    int[] array = {skinThicknes, attackDamage, skinCoulor, canFly, canSwing, speed, flySpeed, swingSpeed};
    Candidate can;
    can = new Candidate(array);
    pop.add(can);
    num++;
}
return pop;

Why are the arrays of every Candidate in pop equal?

---

This is the constructor for Candidate . All those variables ( skinTicknes , attackDamage , etc.) are private static int s.

public Candidate(int[] geno){
    skinTicknes = geno[0];
    attackDamage = geno[1];
    skinCoulor = geno[2];
    canFly = geno[3];
    canSwing = geno[4];
    speed = geno[5];
    flySpeed = geno[6];
    swingSpeed = geno[7];
}

Answer 1

If you read the API you'll note that rnd.nextInt(1) will always return zero (0). This means your canFly and canSwing values will always be the same, which in turn means your flySpeed and swingSpeed will always be the same.

After that, I think we need to see the definition of Candidate to see why the rest is always the same. What makes you believe all the elements of the ArrayList are the same? Can you show us the code for this too?