// Main.java

package javaapplication;

import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.ParseException;
import javax.swing.JButton;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class Main {

  public Main() {
    JFrame frame = new JFrame();
    final RegexFormatter rf = new RegexFormatter("(\\w)?flavio(\\w)?"); //responsável pela validação do texto.
    final JFormattedTextField tf = new JFormattedTextField(rf);
    frame.setLayout(new GridLayout(2, 1));
    frame.add(tf);
    JButton b = new JButton("Testar...");
    b.addActionListener(new ActionListener() {

      public void actionPerformed(ActionEvent e) {
        try {
          JOptionPane.showMessageDialog(null, rf.stringToValue(tf.getText()));
        } catch (ParseException ex) {
          JOptionPane.showMessageDialog(null, ex.getMessage());
        }
      }
    });
    frame.add(b);
    frame.setSize(new Dimension(300, 100));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    new Main();
  }
}