Grabbing int from string in Java

Question

What I want to do:

When the user types in a 3 digit int, it will list the integers and then add them. So the output should look like this

Please enter 3 digit number: 123
The first digit is: 1
The second digit is: 2
The third digit is: 3
The sum is: 6

Here is my code

//Author: Sean Cantwell
//Date: October 13, 2016
//Purpose: Grab ints and add them

import java.util.*;
import java.io.*;
public class MathChallenge
{
    public static void main(String args[])
    {
        Scanner kbReader1 = new Scanner(System.in);
        System.out.print("Enter a three digit number: ");
        number = kbReader1.next();
        String firstNum = number.substring(0,1);
        String secondNum = number.substring(1,2);
        String thirdNum = number.substring(2,3);
        System.out.println("The first digit is " + firstNum);
        System.out.println("The second digit is " + secondNum);
        System.out.println("The third digit is " + thirdNum);
        //ADD DIGITS TOGETHER HERE

    }
}

Answer 1

Use Integer.parseInt():

int firstInt = Integer.parseInt(firstNum);

etc, and then add them.

For added benefit, handle the NumberFormatException properly in case the user enters something that is not all digits.