Question

JAVA: Rewrite the following code to where the inputs are from a file. The file name will be from the input from the user scanner.

CODE:
import java.util.*;
public class Q1
{
public static int sumOD (int k)
{
int sumOD = 0;
int in = k;
while (in != 0)
{
int digitON = in % 10;
sumOD += digitON;
in /= 10;
}
return sumOD;
}
  
public static void main(String[] args)
{
int n, i, k;
System.out.println("Enter the number of integers: ");
Scanner keyboard = new Scanner(System.in);
n = keyboard.nextInt();
for (i = 0; i < n; i++)
{
System.out.println("Enter the number: ");
Scanner keyboard2 = new Scanner(System.in);
k = keyboard2.nextInt();
if (k < 0)
System.out.println("The integer is negative.");
else
System.out.println("The sum of digits is: " + sumOD(k));
}
}
}

Answer 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;

public class Q1 {
    public static int sumOD(int k) {
        int sumOD = 0;
        int in = k;
        while (in != 0) {
            int digitON = in % 10;
            sumOD += digitON;
            in /= 10;
        }
        return sumOD;
    }

    public static void main(String[] args) {
        int n, i, k;
        Scanner keyboard = new Scanner(System.in);
        System.out.print("Enter file name: ");
        File file = new File(keyboard.nextLine());
        try {
            Scanner fin = new Scanner(file);
            n = fin.nextInt();
            for (i = 0; i < n; i++) {
                k = fin.nextInt();
                if (k < 0)
                    System.out.println("The integer is negative.");
                else
                    System.out.println("The sum of digits is: " + sumOD(k));
            }
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " is not found!");
        }
    }
}