моя ошибка java.lang.NumberFormatException

Question

Я использую jcreator. В нем говорится, что процесс завершен, но когда вы переходите к переключению, то случай 4, затем выбирайте числа 1-9, он говорит, что java.numberformatexception. Что вызывает это и как я могу это исправить? Я просто новичок здесь.

import javax.swing.JOptionPane; 

public class Exer29A { 

    public static String inputdialog(String s) 
    { 
     JOptionPane.showInputDialog(null,s); 
     return s; 
    } 
    static void messagedialog(String r) 
    { 
     JOptionPane.showMessageDialog(null, r); 
    } 
    public static void main(String[] args) { 
     int xx, x1, x2; 
     String n1, n2, LName, MName, FName; 
     FName = JOptionPane.showInputDialog(null, "What's your first name?"); 
     MName = JOptionPane.showInputDialog(null, "What's your Middle name?"); 
     LName = JOptionPane.showInputDialog(null, "What's your Last name?"); 
     n2 = JOptionPane.showInputDialog(null, "So you are " + FName.substring(0,1).toUpperCase() + FName.substring(1).toLowerCase() + " " + MName.substring(0,1).toUpperCase() + MName.substring(1).toLowerCase() + " " + LName.substring(0,1).toUpperCase() + LName.substring(1).toLowerCase() + " " + "Do you wish to continue?[Y/N]"); 

     if (n2.equalsIgnoreCase("Y")) 
      { 
       x1 = Integer.parseInt(JOptionPane.showInputDialog(null, "What do you want to do? \n 1. Add 2 integers \n 2. Area of a rectangle \n 3. Area of a triangle \n 4. Know your fate.")); 
        switch (x1) 
        { 
        case 1: 
        { 
         x1 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter 1st integer.")); 
         x2 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter 2nd integer")); 
         messagedialog("The sum of two numbers is " + (x1+x2)); 
        } 
        break; 
        case 2: 
        { 
         x1 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter 1st integer.")); 
         x2 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter 2nd integer")); 
         messagedialog("The area of the triangle is " + (x1*x2)); 
        } 
        break; 
        case 3: 
        { 
         x1 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter base.")); 
         x2 = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter height")); 
         messagedialog("The are of the triangle is " + ((double)(0.5*x1*x2))); 
        } 
        case 4: 
        { 
         xx = Integer.parseInt(inputdialog("Choose numbers 1-9")); 
        { 

          if (xx==1) 
           messagedialog("You will be successful!"); 
          else if (xx==2) 
           messagedialog("You will have a beautiful life. Blessings would come to you."); 
          else if (xx==3) 
           messagedialog("You are handsome/gorgeous. But....."); 
          else if (xx==4) 
           messagedialog("You must study well."); 
          else if (xx==5) 
           messagedialog("Unfortunately, you are unfortunate."); 
          else if (xx==6) 
           messagedialog("You will be an environmentalist. You will be called the Keeper of the Forest."); 
          else if (xx==7) 
           messagedialog("You are nothing but luck. You will be poured out with luck."); 
          else if (xx==8) 
           messagedialog("8. Nothing but a number. Try again."); 
          else 
           messagedialog("Endowed with the gift to serve others, people with the lucky number 9 are able to freely create an easy and relaxed atmosphere. /n Your humanity is welcomed among their friends. Besides, they are brilliant, funny, smart and generous. ");  
         } 
        } 
        break; 
        default: 
         messagedialog("invalid"); 
        } 
      } 
     else if (n2.equalsIgnoreCase("N")) 
      System.exit(0); 
     else 
      messagedialog("INVALID"); 

    } 

} 

Исключение StackTrace:

Exception in thread "main" java.lang.NumberFormatException: For input string: "Choose numbers 1-9" 
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) 
    at java.lang.Integer.parseInt(Integer.java:580) 
    at java.lang.Integer.parseInt(Integer.java:615) 
    at Exer29A.main(Exer29A.java:50) 

Answer 1

В отличие от всех других вызовов, для случая '4', вы называете inputDialog(...) вместо JOptionPane.showInputDialog(null, "Enter base."). Это не главная проблема.

Основная проблема чтоinputDialog(...) возвращается. Это не то же самое, что возвращается JOptionPane.showInputDialog(null, "Enter base.").