How to do unit test of 16 digit Generated Random number [closed]

Question

Here i'm facing one problem that i have to do unit testing of 16 Digits of Generated Random( 9872 5432 8765 0987, 9852 7412 6587 2365.........n) number so these Random Number are generated from Sql queries, i have to check uniqueness How to do unit testing for this scenario is there any approach, or code or tool to perform this operation please tell me with simple demo

Thanks in advance

Answer 1

You do not need any special tool. Just pure Java and some maths (or minimal search-over-the-internet-or-at-least-over-the-stackexchange skills).

Here is your demo.

You only need to rework it for your input and for Assertion mechanism of your unit-test framework.

public class TestNumbers {

    final static int numberLength = 3;

    public static void main(String[] args) {

        int[] testArrayOk = new int[]{
            123,
            321,
            111,
        };
        int[] testArrayWithNoUnique = new int[]{
            123,
            321,
            123,
        };
        int[] testArrayWithWrongLength = new int[]{
                123,
                321,
                12,
        };

        testAll(testArrayOk);
        testAll(testArrayWithNoUnique);
        testAll(testArrayWithWrongLength);
        
    }

    static void testAll(int[] inputArray){
        testForDups(inputArray);
        testForLength(inputArray);
    }
    
    static boolean testForDups(int[] inputArray){
        Set<Integer> findDupsSet = new HashSet<Integer>();
        for (int item : inputArray)
        {
            if (findDupsSet.contains(item)) {
                System.out.println("Dup detected in array: " + Arrays.toString(inputArray));
                return true;
            }
            findDupsSet.add(item);
        }
        return false;
    }

    static boolean testForLength(int[] inputArray){
        for(int i: inputArray){
            if(1 + (int)Math.log10(i) != numberLength){
                System.out.println("Item of improper length detected in array: " + Arrays.toString(inputArray));
                return true;
            }
        }
        return false;
    }
}

Output:

Dup detected in array: [123, 321, 123]

Item of improper length detected in array: [123, 321, 12]

Solutions are taken from:

• Check for duplicates in array: https://stackoverflow.com/questions/3951547/java-array-finding-duplicates
• Check for number length: https://stackoverflow.com/questions/1306727/way-to-get-number-of-digits-in-an-int