/**
 * Sample project that converts a decimal number to a hexadecimal
 * and binary number.
 *
 * Converter is a single-class application and is aimed at novice students
 * who have just started their Java course.
 */
public class Converter
{
    /**
     * Main method for the Converter class.
     */
    public static void main (String arguments[])
    {

        /**
         * First we ensure that the user has provided us with
         * a parameter that we can use to do the conversion with.
         */
        if (arguments.length == 0)
        {
            System.out.println ("Usage :");
            System.out.println ("javac Converter ");
            System.exit (1);
        }

        /**
         * Now that we have a parameter, let's try to convert it
         * to a number. If we fail, we give an error message and
         * terminate program execution.
         */
        int number = 0;

        try
        {
            number = Integer.parseInt (arguments [0]);
        }
        catch (NumberFormatException e)
        {
            System.out.println ("The number specified is not a valid decimal!");
            System.exit (2);
        }

        /**
         * Once we get here we know the number is a valid decimal number.
         * Output the different formats.
         */
        System.out.print ("The number specified is  : ");
        System.out.println (number);

        System.out.print ("The hexadecimal value is : ");
        System.out.println (Integer.toHexString (number));

        System.out.print ("The binary value is      : ");
        System.out.println (Integer.toBinaryString (number));

        System.out.print ("The octal value is       : ");
        System.out.println (Integer.toOctalString (number));

    }
}