Java tutorial
import javax.swing.JFormattedTextField; import javax.swing.JFrame; import javax.swing.text.MaskFormatter; public class Main { String formatString = "##/######"; MaskFormatter formatCNP = createFormatter(formatString); JFormattedTextField jtfCNP = new JFormattedTextField(formatCNP); JFrame frame = new JFrame("MaskFormatter Test"); public Main() { jtfCNP.setColumns(20); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(jtfCNP); frame.pack(); frame.setVisible(true); } MaskFormatter createFormatter(String format) { MaskFormatter formatter = null; try { formatter = new MaskFormatter(format); formatter.setPlaceholderCharacter('.'/*or '0' etc*/); formatter.setAllowsInvalid(false); // if needed formatter.setOverwriteMode(true); // if needed } catch (java.text.ParseException exc) { System.err.println("formatter is bad: " + exc.getMessage()); } return formatter; } public static void main(String[] args) { new Main(); } }