Java Program to add two binary numbers

Program

import java.util.Scanner;
public class AddTwoBinaryNumbers {
    public void addBinaryNumbers(long binaryNum1, long binaryNum2)
    {
        int i = 0;
        int  carry = 0;
        int[] sum = new int[20];
        while (binaryNum1 != 0 || binaryNum2 != 0) 
        {
          sum[i++] = (int)((binaryNum1 % 10 + binaryNum2 % 10 + carry) % 2);
          carry = (int)((binaryNum1 % 10 + binaryNum2 % 10 + carry) / 2);
          binaryNum1 = binaryNum1 / 10;
          binaryNum2 = binaryNum2 / 10;
        }
        if (carry != 0) {
        sum[i++] = carry;
        }
        --i;
        while (i >= 0) {
            System.out.print(sum[i--]);
        }
    }
    public static void main(String[] args)
    {
        AddTwoBinaryNumbers addTwoBinaryNumbers = new AddTwoBinaryNumbers();
        Scanner reader = new Scanner(System.in);
        System.out.print("Enter the first binary number: ");
        long binaryNum1 = reader.nextLong();
        System.out.print("Enter the second binary number: ");
        long binaryNum21 = reader.nextLong();
        System.out.println("Sum of two binary numbers is: ");
        addTwoBinaryNumbers.addBinaryNumbers(binaryNum1,binaryNum21);
    }
}

Output

$ javac AddTwoBinaryNumbers.java
$ java AddTwoBinaryNumbers
Enter the first binary number: 100101
Enter the second binary number: 101101
Sum of two binary numbers is:
1010010