I'm trying to make a TTRPG dice roller with Java within a Java FX app. So far, this is what I have: the program skips the try block and shows nothing in the screen, the console shows no errors. Can you help me? I'm coding this for a personal project. I'm also a student, so I don't know much about coding and I try to avoid AI as much as possible.

public class DiceController {

    @FXML
    Label rollResult, separatedDice;
    @FXML
    TextField diceNotationField;
    @FXML
    Button diceRollButton;

    public void roll() {
        try {

            // get text from field
            String diceNotation = diceNotationField.getText();

            // Use a regex tp detect dice notation
            Pattern regex = Pattern.compile("(\\d+)?d(\\d+)(?:([\\+\\*\\/\\-])(\\d+))?");
            Matcher m = regex.matcher(diceNotation);

            String diceQuantity = "";
            String diceSize = "";
            String diceSign = "";
            String diceModifier = "";

            // Call Random to create a random number
            Random rand = new Random();

            // if the dice quantity is null is set to 1
            if (diceQuantity == null || diceQuantity.isEmpty()) {
                diceQuantity = "1";
            }
            
            // regex matcher check
            if (!m.matches()) {
                rollResult.setText("Intruduce a valid dice notation");
            } else if (m.matches()) {
                diceQuantity = m.group(1);
                diceSize = m.group(2);

                
                
                // Create an array to store the result of each dice
                int diceResultArray[] = new int[Integer.parseInt(diceQuantity)];

                // this variable will generate a random number rolling the dice
                int randomResultInDice = 0;

                // this variable stores the total result
                int total = 0;
                
                for (int i = 0; i < Integer.parseInt(diceQuantity); i++) {
                    // generates a random number on the dice,
                    randomResultInDice = rand.nextInt(1, Integer.parseInt(diceSize) + 1);
                    // stores the separate values of each dice's results in an array
                    diceResultArray[i] = randomResultInDice;
                    // sums the result of the separate dice
                    total += randomResultInDice;
                }

                
                // if there's no sign the string stays empty, else, the regex group is
                // recognized and the corresponding operation is performed
                if (diceSign == null || diceSign.isEmpty() && diceModifier == null || diceModifier.isEmpty()) {
                    diceSign = "";
                    diceModifier = "";
                } else {
                    diceSign = m.group(3);
                    diceModifier = m.group(4);

                    // stores the total result of the dice plus the operation corresponding to the
                    // modifier
                    int totalMod = 0;

                    switch (diceSign) {
                    case "+":
                        totalMod = total + Integer.parseInt(diceModifier);
                        rollResult.setText(String.valueOf(totalMod));
                        separatedDice.setText(String.valueOf(Arrays.toString(diceResultArray)));
                        break;
                    case "-":
                        totalMod = total - Integer.parseInt(diceModifier);
                        rollResult.setText(String.valueOf(totalMod));
                        separatedDice.setText(String.valueOf(Arrays.toString(diceResultArray)));
                        break;
                    case "*":
                        totalMod = total * Integer.parseInt(diceModifier);
                        rollResult.setText(String.valueOf(totalMod));
                        separatedDice.setText(String.valueOf(Arrays.toString(diceResultArray)));
                        break;
                    case "/":
                        if (Integer.parseInt(diceModifier) != 0) {
                            totalMod = total / Integer.parseInt(diceModifier);
                            rollResult.setText(String.valueOf(totalMod));
                            separatedDice.setText(String.valueOf(Arrays.toString(diceResultArray)));
                        } else {
                            totalMod = total;
                            rollResult.setText(String.valueOf(total));
                        }
                        
                        break;
                    default:
                        rollResult.setText(String.valueOf(total));
                        separatedDice.setText(String.valueOf(Arrays.toString(diceResultArray)));
                        break;
                    }
                }

            }

        } catch (Exception e) {
            rollResult.setText(e.toString());
            System.out.println(e);
        }
    }
}