import javax.swing.*; import java.util.regex.*; public class joptionpane { public static void main(String[] args){ int category_user = 0; boolean aa = false; do{ String input = JOptionPane.showInputDialog( null,

            "Please select the category \n"
                + "1. IT \n"
                + "2. Science \n"
                + "3. Maths",

                "Input",

                JOptionPane.INFORMATION_MESSAGE
            );
            Pattern p = Pattern.compile("[A-Z,a-z,&%$#@!()*^]");
            Matcher m = p.matcher(input);
            if (m.find()) {
         JOptionPane.showMessageDialog(null, "Please enter only numbers");
            }
            else (m.find())
                    {
             category_user = Integer.parseInt(input);

            }
    }while (!aa || category_user < 1 || category_user>4);

}

\ hello!!please help me!i need to validate the user input on the joptionpane,and if the user enter is a character then it is supposed to return the select category question again.if the user enter correct then the loop will break.however, the following do while will keep looping!how do i modify the codes to make it right?thank for your help.