Java - Is there any way to break while loop while scanning integers in ArrayList without giving invalid input?

Question

The while loop breaks only if I give some non-integer input. What I want is to break it with blank input (just hit "Enter" without any input)

import java.util.ArrayList;
import java.util.Scanner;

public class SingleElement {

public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    ArrayList<Integer> list = new ArrayList<Integer>();
    int in = (Integer) null;
    while(scan.hasNextInt()){   
        list.add(scan.nextInt());
    }
  }
}

Thanks!

Answer 1

Not really.

The program has a hard coded expectation to only find a list of incoming numbers.

So you would have to define a special number to mean: stop looping.

To make things easier to control, you could read raw strings from the scanner. And then any non number means: stop looping.

Answer 2

You should parse the input as a String and then convert that into an int via code within a try/catch . If you get an exception in converting the String into int , you know you got a non-integer, and you can break the while loop from there.