roman Calc

package roman_calculator;

import java.util.*;

public class romanCalculator
{
    // scan can now be used anywhere within this class
    Scanner scan = new Scanner(System.in);

    // This routine either returns false if the use wants to quit,
    // or it does one Roman Calculator calculation
    boolean doCalculation()
    {
        char operand,operator = getOperator() ;

        // Call getOperator to get either - + * / or q.
        // If q is returned, we return a false.

        if (operator == 'q')
        	return false;

        // If the operator is + - * or / then call
        // getOperand(1) for the first operand and
        // call getOperand(2) for the second operand

        int operand1 = getOperand(1),operand2 = getOperand(2);
        int answer = doArithmetic (operand1,operand2, operator);
        String sAnswer = convert_to_Roman(answer);
        System.out.println("Answer = "+answer);


        // call doArithmetic and print out the result using
        // convert_to_Roman to generate Roman Numeral output.

        return true;
    }

    // This routine prompts the user with
    // Operator: +  -  *  /  q for quit
    // If none of these are entered, this routine complains and
    //   prompts the user again.  Otherwise the operator is returned.
    char getOperator()
    {
    	System.out.println("Enter operation: + - * / q (q ==> quit) : ");
        String input = scan.next();
        return 0;
    }

    // This routine prompts the user for either operand1 or operand2
    // depending on the value of which.  This routine uppercases the
    // input and calls convert_from_Roman to create an integer.
    // If the input is invalid ( negative return from convert_from_Roman)
    // then complain and prompt the user again.
    int getOperand(int which)
    {
        System.out.println("Enter operand" + which);
        String op = scan.next();
        return convert_from_Roman(op);

    }


    // Routine to convert an integer to a Roman Numeral String.
    // When you do this routine, you might find it handy to
    // create a utility routine that looks like:
    //String addRomanDigit(String starting, int num, char digit)
    String convert_to_Roman(int value)
    {
        String roman = "";
        while (value > 0 && value < 4000)
        	switch (value)
        	{
        	case 1000:
        		roman +='M';
        	case 500:
        		roman +='D';
        	case 100:
        		roman +='C';
        	case 50:
        		roman +='L';
        	case 10:
        		roman +='X';
        	case 5:
        		roman +='V';
        	case 1:
        		roman +='I';
        		break;
        	}
        return roman;
    }


    // Convert Roman Numeral String to an integer.  If the
    // Roman Numeral String is invalid, return -1.
    int convert_from_Roman(String value)
    {
        String s = value.toUpperCase();
        s = s.trim();
        int len = s.length();
        int total = 0;

        for(int i = len; i > 0; i++)
        {
        	char c = value.charAt(i);
        	switch(c)
        	{
        	case 'M':
        		total += 1000;
        	case 'D':
        		total += 500;
        	case 'C':
        		total += 100;
        	case 'L':
        		total += 50;
        	case 'X':
        		total += 10;
        	case 'V':
        		total += 5;
        	case 'I':
        		total += 1;
        		break;
        	}
        }
        return total;
    }

    // Perform the arithmetic indicated by the operator (+ - * /)
    void doArithmetic(int operand1, int operand2, char operator)
    {
    	switch (operator)
    	{
    	case '+':
    		return;
    	case '-':
    		return;
    	case '*':
    		return;
    	case '/':
    		return;
    	}
    }
    public static void main(String[] args)
    {
    	romanCalculator rc = new romanCalculator();
    while (rc.doCalculation())
        {
            System.out.println();  // blank line
        }
        System.out.println("Finished Roman Computations");
    }

}