Thread: While loop, help with looping.

I need help looping my program that I am doing. First off what I am trying to do is prompt the user if they would like to calculate again. If they type in the string "y" then It will loop them back into the beginning. If they type in the string "n" it will break; and the program will be done.

package monthypayment2;
import java.text.NumberFormat;
import java.util.Scanner;
 
 
public class Monthypayment2 {
    private static double monthlypay1;
    private static String choice;
    private static boolean n;
    private static String False;
    private static boolean y;
 
 
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
 
        //format number and currency
       NumberFormat NF = NumberFormat.getCurrencyInstance();
 
 
        double months;
        double numyears;
        double loanamount;
        double rate;
        double monthlypay1;
        y = true;
        n = false;
 
 
 
 
        //prompt loan amount
        System.out.print("Enter Loan Amount:");                           
        loanamount = in.nextDouble();
 
        //prompt rate
        System.out.print("Enter Rate:");
         rate = in.nextDouble();
 
        //parse these double.parsedouble();
 
 
         //prompt years
        System.out.print("Enter Number of Years:");
        numyears = in.nextDouble();
 
        rate = rate / 1200;
        months = 12 * numyears;
 
 
      //calculation monthly
       monthlypay1 = loanamount * rate * (Math.pow (1 + rate, months))
               / (Math.pow (1+ rate, months))-1;
 
       int repeat = 1;
 
         while (monthlypay1 > 0) {
        System.out.println("The Monthly Payment is: $" + monthlypay1);   
         break; }
 
 
        while (monthlypay1 < 0) {
            System.out.print("You need to enter positive numerical data!");
            break;
 
 
         }
            System.out.print("Would you like to continue calculations(y/n)?");
            choice = in.nextLine();
    }
}

First off I've tried this. Problem with this is it loops when choosing "n" and doesn't loop when pressing "y" So I decided to start over
for perhaps an easier method.

   if (monthlypay1 >= 0) {
        System.out.print("The Monthly Payment is: $ " + monthlypay1); 
 
 
        System.out.print("Would you like to calculate again? (Y/N)"); 
        choice = in.next();
        while (((Character)'y').toString().equals(choice)); {
            main(null);
            while (((Character)'n').toString().equals(choice)); {
            System.out.print("Thanks for using the program.. Goodbye"); 
        }
        }
 
        }
 
 
    else {
        System.out.print("You need to enter Positive Numerical Data!");}
 
 
        }
}

I am still relatively new to Java. If you can make an example code of how to loop the user back after they choose the string / character that is associated with yes then please do provide it.

Sorry. No one in the thread answered my question so I thought I could post a new one. So I suppose a moderator can close this thread.