How to use joptionpane inside try cat

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Java

Swing

Eclipse

Hello I'm trying to use the JOptionPane here to send a warning to the user that he needs to enter a valid input in correct format, but the JOptionPane is not showing when I entered a wrong input. I don't know what is my mistake.

boolean format = false;
do {

      System.out.print("Enter time in: ");
      in = get.next();
      try {

          LocalTime time = LocalTime.parse(in);
          DateTimeFormatter pattern = DateTimeFormatter.ofPattern("hh:mm a");
          System.out.println(time.format(pattern));
          format = true;
      } catch (Exception e) {
          format = false;
          JOptionPane.showMessageDialog(null, "Input invalid",
                          "Error", JOptionPane.ERROR_MESSAGE);
      }

}while(!format);

What I have tried:

I tried to put the JOptionPane above the try-catch and it's showing normally, but if I put it in the catch block it's not showing.