Pblm with exception handling

Question

when I enter an input 10a in the the dialogbox Enter monthly payment , it prompts me to enter a valid data. If I again enter 10a , actualy Enter valid data dialog box must be displayed.Instead it displays Enter monthly payment . Even if I enter 100 in Enter valid data dialog box, it again displays Enter monthly payment. I'v been try to fix this. Can anyone help me. Thanks
import javax.swing.*;
import java.text.*;
public class TestTryCatch{
   public static void main(String[] args){
      String choice = "";
      boolean tryAgain = true;
      String string = "1";
      while (!(choice.equalsIgnoreCase("x"))){
              while (tryAgain){
                   System.out.println("tryAgain before try :" + tryAgain);
             try{
                     String paymentString = JOptionPane.showInputDialog(
                                                null,
                                                     "Enter monthly payment: ",
                                                     "Future Value",
                                                 JOptionPane.PLAIN_MESSAGE);
                    double monthlyPayment = Double.parseDouble(paymentString);
                    //tryAgain = false;
                    paymentString = string;
                    monthlyPayment = Double.parseDouble(paymentString);
                    System.out.println("1");
                   /* Static method to validate monthlyPayment*/
                 if(monthlyPayment <=0)
                    validateMonthlyPayment(monthlyPayment);
                 String rateString = JOptionPane.showInputDialog(
                                         null,
                                         "Enter yearly interest rate: ",
                                         "Future Value",
                                         JOptionPane.PLAIN_MESSAGE);
                   double interestRate = Double.parseDouble(rateString);
                   //tryAgain=false;
                   System.out.println("2");
                     /* Static method to validate interestRate*/
                   interestRate = validateInterestRate(interestRate);
                   double monthlyInterestRate = interestRate/12/100;
                   String yearsString = JOptionPane.showInputDialog(
                                             null,
                                              "Enter number of years: ",
                                              "Future Value",
                                           JOptionPane.PLAIN_MESSAGE);
                  int years = Integer.parseInt(yearsString);
                years = validateYears(years);
                   int months = years * 12;
                   //tryAgain = false;
                   double futureValue = calculateFutureValue(monthlyPayment,
                                                                     months,
                                                                     monthlyInterestRate);
                     NumberFormat currency = NumberFormat.getCurrencyInstance();
                    NumberFormat percent = NumberFormat.getPercentInstance();
                    percent.setMinimumFractionDigits(2);
                    String message =
                                 "Monthly payment: " + currency.format(monthlyPayment) + "\n"
                               + "Yearly interest rate: " + percent.format(interestRate/100) + "\n"
                               + "Number of years: " +  years + "\n"
                               + "Future value: " + currency.format(futureValue) + "\n\n"
                               + "To continue, press Enter.\n"
                               + "To exit, enter 'x': ";
                    choice = JOptionPane.showInputDialog(null,
                                                                  message,
                                                                 "Future Value",
                                                                 JOptionPane.PLAIN_MESSAGE);
                    System.out.println("choice is : " + choice);
             } // end try loop
                //tryAgain = false;
                   catch(NumberFormatException e){
                        string = JOptionPane.showInputDialog(
                                                          null,
                                                        "Enter a valid data: ",
                                                        "Future Value",
                                                      JOptionPane.PLAIN_MESSAGE);
                       /* String rateString = JOptionPane.showInputDialog(
                                                              null,
                                                             "Enter a valid interest rate: ",
                                                             "Future Value",
                                                            JOptionPane.PLAIN_MESSAGE);
                       double validateRate = Double.parseDouble(rateString);
                       String yearsString = JOptionPane.showInputDialog(
                                                               null,
                                                              "Enter valid number of years " +"\n"+
                                                              "between 0 to 100 : ",
                                                              "Future Value",
                                                              JOptionPane.PLAIN_MESSAGE);
                int years = Integer.parseInt(yearsString);*/
                  } // end catch
               }//end tryAgain
       } // end while loop
      System.exit(0);
   }//end main
   private static double calculateFutureValue(double monthlyPayment,
   int months, double interestRate){
      int i = 1;
      double futureValue = 0;
      while (i <= months) {
         futureValue = (futureValue + monthlyPayment) *
         (1 + interestRate);
         i++;
      return futureValue;
   } // end calculateFutureValue method
   private static void validateMonthlyPayment(double monthlyPayment){
      while(monthlyPayment <= 0) { // while loop to validate monthlyPayment
              String paymentString = JOptionPane.showInputDialog(
                                             null,
                                           "Enter a valid monthly payment: ",
                                           "Future Value",
                                         JOptionPane.PLAIN_MESSAGE);
              monthlyPayment = Double.parseDouble(paymentString);
       } // end while loop monthlyPayment validation
   } // end validateMonthlyPayment
   private static double validateInterestRate(double validateRate){
      while(validateRate <= 0) { // while loop to validate interestrate
              String rateString = JOptionPane.showInputDialog(
                                            null,
                                           "Enter a valid interest rate: ",
                                           "Future Value",
                                          JOptionPane.PLAIN_MESSAGE);
              validateRate = Double.parseDouble(rateString);
      } // end while loop
      return validateRate;
   } // end validateInterestRate method
   private static int validateYears(int years){
          while(years <= 0 || years>= 100){
              String yearsString = JOptionPane.showInputDialog(
                                            null,
                                           "Enter valid number of years " +"\n"+
                                           "between 0 to 100 : ",
                                           "Future Value",
                                         JOptionPane.PLAIN_MESSAGE);
         years = Integer.parseInt(yearsString);
      return years;
}

Answer 1

Too much code. Yo udon't need all that Swing stuff to see how to make this work.
This works - see if you can adapt it:
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
public class TryAgainTester
    public static void main(String [] args)
        double payment      = 0.0;
        boolean tryAgain    = true;
        String entry        = "";
        while (tryAgain)
            try
                System.out.print("Enter payment: ");
                entry       = getString(System.in);
                payment     = Double.parseDouble(entry);
                tryAgain    = false;
            catch (NumberFormatException e)
                System.err.println("Invalid entry: " + entry);
                tryAgain = true;
            catch (Exception e)
                e.printStackTrace();
        System.out.println("payment: " + payment);
    public static String getString(InputStream in) throws IOException
        String value = "";
        InputStreamReader isr = new InputStreamReader(in);
        BufferedReader br       = new BufferedReader(isr);
        value = br.readLine();
        return value;