Create custom formatter for JFormattedTextField in Java

import java.awt.BorderLayout;
import java.text.ParseException;
/*w ww. j a v  a2  s  .  c  om*/
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.text.DefaultFormatter;

public class Main {
  public static void main(final String args[]) throws ParseException {
    JFrame frame = new JFrame("Formatted Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JFormattedTextField tf = new JFormattedTextField(new MyFormatter());
    tf.setColumns(10);

    frame.add(tf, BorderLayout.NORTH);

    frame.add(new JTextField(), BorderLayout.SOUTH);
    frame.setSize(250, 100);
    frame.setVisible(true);
  }
}
class MyFormatter extends DefaultFormatter {

  public MyFormatter() {
    super();
  }
  public String valueToString(Object object) throws ParseException {
    return super.valueToString(object);
  }
  public Object stringToValue(String string) throws ParseException {
    try {
      int value = Integer.parseInt(string);
      if (value != 1) {
        return "" + value;
      } else {
        return "Invalid";
      }
    } catch (Exception e) {
      return "Invalid";
    }
  }
}