4-21 FileSum2

Post date: Mar 5, 2014 10:30:17 AM

//This version of the program confirms that the Numbers.txt file exists before opening it.

package filesum2;

import java.io.*;

import java.util.Scanner;

public class FileSum2

{

public static void main(String[] args)throws IOException

{

double sum = 0.0; // Accumulator, initialized to 0

// Make sure the file exists.

File file = new File( "Numbers.txt");

if (!file.exists())

{

System.out.println("The file Numbers.txt is not found.");

System.exit(0);

}

// Open the file for reading.

Scanner inputFile = new Scanner(file);

// Read all of the values from the file

// and calculate their total.

while (inputFile.hasNext())

{

// Read a value from the file.

double number = inputFile.nextDouble();

// Add the number to sum.

sum = sum + number;

}

// Close the file.

inputFile.close();

// Display the sum of the numbers.

System.out.println("The sum of the numbers in Numbers.txt is " + sum);

}

}