Java File

import java.io.*;
public class ReadFile{
    public static void main(String[] args) throws Exception {
        int sum=0;
        File f = new File("C:/numbers.txt");
            FileReader fr = new FileReader(f);
            BufferedReader reader = new BufferedReader(fr);
            String st = "";
            while((st = reader.readLine()) != null) {
                int num=Integer.parseInt(st);
                sum+=num;
            }
            File out=new File("C:/total.txt");
            BufferedWriter bw=new BufferedWriter(new FileWriter(out));
            bw.write(Integer.toString(sum));
            bw.close();
            System.out.println("File is created.");
        }
    }