Thread: Java Do..while loop problem

I'm trying to put a do...while loop into this code

import javax.swing.JOptionPane;
 
public class UpperLowerCase2
{
    public static void main(String[] args)
    {
        int choice;
        String someString,menu;
 
 
 
        menu = "Enter\n"
             + "(1) Enter a string\n"
             + "(2) Convert the string to all uppercase\n"
             + "(3) Convert the String to all lowercase\n"
             + "(4) Quit";
do{
             someString = JOptionPane.showInputDialog( menu );
 
             choice = Integer.parseInt( someString );
 
 
            switch (choice)
 
            {
                case 1: enterAString();
 
 
 
                case 2: stringToUppercase();
 
 
                case 3: convertStringLower();
 
 
                case 4: System.out.println("Quit");
 
            }
 
}while(choice!=4);
 
}
public static void enterAString()
{
    String outputmessage,string;
    string = JOptionPane.showInputDialog("Enter Your String");
    outputmessage = "You entered " + string;
    JOptionPane.showMessageDialog( null, outputmessage );
 
System.exit(0);
}
 
public static void stringToUppercase()
{
    String outputMessage2,string2;
    string2 = JOptionPane.showInputDialog("Enter String to convert to UPPERCASE");
    string2 = string2.toUpperCase();
    outputMessage2 = " Here Ya Go " + string2;
    JOptionPane.showMessageDialog(null, outputMessage2);
    System.exit(0);
}
 
public static void convertStringLower()
{
    String outputMessage3,string3;
    string3 = JOptionPane.showInputDialog("Enter String to convert to lowercase");
    string3 = string3.toLowerCase();
    outputMessage3 = "Here Ya Go " + string3;
    JOptionPane.showMessageDialog(null, outputMessage3);
    System.exit(0);
}
 
}

However it isn't looping can somebody fix it for me or tell me what i need to do. The program runs, but it dosen't loop. Help Pleez

What does it do instead? What do you think those System.exit() calls do?

System.exit(0) terminates your program whether u are in a loop or not.