import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;

public class BinaryOutputDemo
{
   public static void main(String[] args)
   {
	  String fileName = "numbers.dat";
      try
      {
         ObjectOutputStream outputStream =
             new ObjectOutputStream(new FileOutputStream(fileName));
//              new ObjectOutputStream(new File(fileName));
        Scanner keyboard = new Scanner(System.in);
         System.out.println("Enter nonnegative integers.");
         System.out.println("Place a negative number at the end.");

         int anInteger;
         do
         {
            anInteger = keyboard.nextInt( );
            outputStream.writeInt(anInteger);
         } while (anInteger >= 0);
         System.out.println("Numbers and sentinel value");
         System.out.println("written to the file " + fileName);
         outputStream.close( );
      }
      catch(FileNotFoundException e)
      {
         System.out.println("Problem opening the file " + fileName);
      }
      catch(IOException e)
      {
         System.out.println("Problem with output to file " + fileName);
      }
   }
}