How do I make sure User input integer type only and integer that is greater than 0?

The problem with your current approach is you've already ready the value from the Scanner before it reaches int input = scan.nextInt();, meaning that by the time you use nextInt, there's nothing in the Scanner to be read and it will wait for the next input from user...

Instead, you could read the String from the Scanner using next, use Integer.parseInt to try and parse the result to an int and then check the result, for example...

Scanner scanner = new Scanner(System.in);
int intValue = -1;
do {
    System.out.print("Please enter a integer value greater than 0: ");
    String next = scanner.next();
    try {
        intValue = Integer.parseInt(next);
    } catch (NumberFormatException exp) {
    }
} while (intValue < 0);

System.out.println("You input " + intValue);

put an if statement inside your while loop like this

if(num <= 0){
   System.out.println("Enter a number greater than zero");
}
else{
   break;
}

You may use a condition in your code but not in the loop as. `

Scanner scan = new Scanner(System.in);
abc: 
while(!scanner.hasNextInt()) 
{
    scanner.next();
}
int input = scan.nextInt();
if(input <= 0){
   goto abc;
}

`

using .isDigit() method then checking to see if that number is greater than 0 if it is a digit