import java.awt.Container;
import java.text.ParseException;
import javax.swing.BoxLayout;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.text.MaskFormatter;
public class Main {
public static void main(String args[]) throws ParseException {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = f.getContentPane();
content.setLayout(new BoxLayout(content, BoxLayout.PAGE_AXIS));
MaskFormatter mf1 = new MaskFormatter("###-###-###");
mf1.setPlaceholderCharacter('_');
JFormattedTextField ftf1 = new JFormattedTextField(mf1);
content.add(ftf1);
MaskFormatter mf2 = new MaskFormatter("(###) ###-####");
JFormattedTextField ftf2 = new JFormattedTextField(mf2);
content.add(ftf2);
f.setSize(300, 100);
f.setVisible(true);
}
}