如何检查JFormattedTextField的值是我需要的？

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Main {
    public static void main(String[] args) {
        JFrame frame = new JFrame("JFormattedTextField Demo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JFormattedTextField formattedTextField = new JFormattedTextField();
        formattedTextField.setValue(0); // 设置初始值为0
        formattedTextField.setColumns(10);

        JButton button = new JButton("Check Value");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Object value = formattedTextField.getValue();
                if (value instanceof Integer) {
                    int intValue = (Integer) value;
                    if (intValue > 0) {
                        JOptionPane.showMessageDialog(frame, "Value is a positive integer.");
                    } else {
                        JOptionPane.showMessageDialog(frame, "Value must be a positive integer.");
                    }
                } else {
                    JOptionPane.showMessageDialog(frame, "Invalid value.");
                }
            }
        });

        JPanel panel = new JPanel();
        panel.add(formattedTextField);
        panel.add(button);

        frame.getContentPane().add(panel);
        frame.pack();
        frame.setVisible(true);
    }
}