The JFormattedTextField allows us to create a text field that can accept a formatted input. In this code snippet we create two formatted text fields that accept a valid phone number and a date.
package org.kodejava.swing;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.swing.text.DateFormatter;
import javax.swing.text.MaskFormatter;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class FormattedTextFieldExample extends JFrame {
public FormattedTextFieldExample() {
initComponents();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new FormattedTextFieldExample().setVisible(true));
}
private void initComponents() {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setTitle("Format User Input");
setSize(new Dimension(500, 500));
getContentPane().setLayout(new FlowLayout(FlowLayout.LEFT));
MaskFormatter mask = null;
try {
// Create a MaskFormatter for accepting phone number, the # symbol accept
// only a number. We can also set the empty value with a place holder
// character.
mask = new MaskFormatter("(###) ###-####");
mask.setPlaceholderCharacter('_');
} catch (ParseException e) {
e.printStackTrace();
}
// Create a formatted text field that accept a valid phone number.
JFormattedTextField phoneField = new JFormattedTextField(mask);
phoneField.setPreferredSize(new Dimension(100, 20));
// Here we create a formatted text field that accept a date value. We
// create an instance of SimpleDateFormat and use it to create a
// DateFormatter instance which will be passed to the JFormattedTextField.
DateFormat format = new SimpleDateFormat("dd-MMMM-yyyy");
DateFormatter df = new DateFormatter(format);
JFormattedTextField dateField = new JFormattedTextField(df);
dateField.setPreferredSize(new Dimension(100, 20));
dateField.setValue(new Date());
getContentPane().add(phoneField);
getContentPane().add(dateField);
}
}
User Input Format
Here are some other characters that can be used in the MaskFormatter class.
| Char | Description |
|---|---|
| # | For number |
| ? | For letter |
| A | For number or letter |
| * | For anything |
| L | For letter, it will be converted to the equivalent lower case |
| U | For letter, it will be converted to the equivalent upper case |
| H | For hexadecimal value |
| ‘ | To escape another mask character |
