Creating an array of random numbers with no duplicates I only need three random numbers within the range of 1-54 (deck of cards) and none of the three numbers can be a duplicate. I cannot use an ArrayList; I must use a standard array. Is the method I chose to check for duplicates good enough? 

public class Test {

public static int genRandom() {
    // generate random int value between 1 and 54
    int random = 1 + (int) (Math.random() * ((54 - 1) + 1));
    return random;
}

public static boolean containsDuplicates(int[] arr) {
    // check to see if positions have matching values
    if (arr[0] == arr[1] || arr[0] == arr[2] || arr[1] == arr[2]) {
        System.out.println("Duplicates Exist");
        // if matching value is found, randomize the array again
        shuffle(arr);
        return true;
    }
    System.out.println("No duplicates");
    return false;
}

public static void shuffle(int[] arr) {
    for (int i = 0; i &lt; arr.length; i++) {
        arr[i] = genRandom();
        System.out.println(arr[i]);
    }
    containsDuplicates(arr);
}

public static void main(String[] args) {

    int[] cards = new int[3];
    shuffle(cards);
}
}
No, not a good way at all.

shuffle and containsDuplicate recursively call each other without guarantee to ever stop doing that. That is the program has a certain probability to die because of stack overflow.

A similar non-recursive version

    public static boolean containsDuplicates(int[] arr) {
        return arr[0] == arr[1] || arr[0] == arr[2] || arr[1] == arr[2];
    }

    public static void shuffle(int[] arr) {
        for (int i = 0; i &lt; arr.length; i++) {
            arr[i] = genRandom();
        }
    }

    public static void main(String[] args) {
        do {
            shuffle();
        } while(containsDuplicates());
    }


doesn't suffer stack overflow, but still may run for indefinitely long time.

As Jerry Coffin mentioned in the comment, a Fisher-Yates algorithm is a way to go.