      1  import java.io.File;

      2  import java.io.FileNotFoundException;

      3  import java.io.PrintWriter;

      4  import java.util.Scanner;

      5

      6  public class PopulationDensity

      7  {

      8     public static void main(String[] args) throws FileNotFoundException

      9     {

     10        // Open input files

     11        Scanner in1 = new Scanner(new File("worldpop.txt"));

     12        Scanner in2 = new Scanner(new File("worldarea.txt"));

     13

     14        // Open output file

     15        PrintWriter out = new PrintWriter("world_pop_density.txt");

     16

     17        // Read lines from each file

     18        while (in1.hasNextLine() && in2.hasNextLine())

     19        {

     20           CountryValue population = new CountryValue(in1.nextLine());

     21           CountryValue area = new CountryValue(in2.nextLine());

     22

     23           // Compute and print the population density

     24           double density = 0;

     25           if (area.getValue() != 0) // Protect against division by zero

     26           {

     27              density = population.getValue() / area.getValue();

     28           }

     29           out.printf("%-40s%15.2f\n", population.getCountry(), density);

     30        }

     31

     32        in1.close();

     33        in2.close();

     34        out.close();

     35     }

     36  }