romanConverter

romanConverter.java

package dojo1_Roman;

public class RomanConverter
{

    public enum Digit
    {
        UNIT, DECIMAL, HUNDRED, THOUSAND
    };

    private static String[] units =
        { "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X" };
    private static String[] tens =
        { "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC", "C" };
    private static String[] hundreds =
        { "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "DM", "M" };
    private static String[] thousands =
        { "M", "MM", "MMM", "IV", "V", "VI", "VII", "VIII", "IX", "X" };// can't display bar on numbers higher than 3K

    public static int unitCount = 0;
    public static int tenCount = 0;
    public static int hundredCount = 0;
    public static int thousandCount = 0;


    public static void processInput(int input) throws Exception
    {
        try
        {
            System.out.println("input is : " + input);
            thousandCount = input / 1000;
            hundredCount = input / 100 - (thousandCount * 10);
            tenCount = input / 10 - (thousandCount * 100 + hundredCount * 10);
            int minus = thousandCount * 1000 + hundredCount * 100 + tenCount * 10;
            unitCount = input - minus;
            System.out.println("thousand: " + thousandCount);
            System.out.println("hundred: " + hundredCount);
            System.out.println("ten: " + tenCount);
            System.out.println("unit: " + unitCount);
        }
        catch (Exception e)
        {
            if (e instanceof NumberFormatException)
            {
                System.out.println("Improper Input : Not a Number");
            }
            else
            {
                System.out.println("Improper Input : No argument passed");
            }
            throw e;
        }
    }

    public static String getDisplayString(int input) throws Exception
    {
        StringBuffer sbfResult = new StringBuffer();
        processInput(input);
        append(sbfResult, Digit.THOUSAND);
        append(sbfResult, Digit.HUNDRED);
        append(sbfResult, Digit.DECIMAL);
        append(sbfResult, Digit.UNIT);
        return sbfResult.toString();
    }

    private static void append(StringBuffer sbfResult, Digit digit)
    {
        switch (digit)
        {
            case UNIT:
                sbfResult.append(units[unitCount - 1]);
                break;
            case DECIMAL:
                sbfResult.append(tens[tenCount - 1]);
                break;
            case HUNDRED:
                sbfResult.append(hundreds[hundredCount - 1]);
                break;
            case THOUSAND:
                sbfResult.append(thousands[thousandCount - 1]);
                break;
        }
    }

}