import java.io.*; class Demo { public static void main(String[] args) { BufferedReader in = null; PrintWriter out = null; int sum = 0; try { in = new BufferedReader(new FileReader(args[0])); out = new PrintWriter(new FileWriter(args[1])); String line; while ((line = in.readLine()) != null) { int n = 0; try { n = Integer.parseInt(line); } catch (NumberFormatException e) { System.out.println("invalid number"); } sum += n; out.println("The sum is " + sum); } out.println("The sum is " + sum); in.close(); // out.close(); } catch (IOException e) { System.out.println(e); } } }