File Name from User Input

import java.util.Scanner;
import java.io.*;

class NamedFileInOut
{
  public static void main (String[] args) throws IOException
  { 
    int num, square;    

    // Scanner for user input
    Scanner user = new Scanner( System.in ); 
    String  inputFileName, outputFileName;

    // prepare the input file
    System.out.print("Input File Name: ");
    inputFileName = user.nextLine().trim();
    File input = new File( inputFileName );      
    Scanner scan = new Scanner( input );      

    // prepare the output file
    System.out.print("Output File Name: ");
    outputFileName = user.nextLine().trim();
    PrintWriter output = new PrintWriter( outputFileName );      

    // processing loop
    while( scan.hasNextInt() )    
    {
      num = scan.nextInt();
      square = num * num ;      
      output.println("The square of " + num + " is " + square);
    }

    // close the output file
    output.close();
  }
}