Field Validation with InputVerify Class

Reference Site: http://java.sun.com/j2se/1.4.2/docs/api/javax/swing/InputVerifier.html


Example :

import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;

// This program demonstrates the use of the Swing InputVerifier class.
// It creates two text fields; the first of the text fields expects the
// string "pass" as input, and will allow focus to advance out of it
// only after that string is typed in by the user.

public class VerifierTest extends JFrame {
public VerifierTest() {
JTextField tf1 = new JTextField ("Type \"pass\" here");
getContentPane().add (tf1, BorderLayout.NORTH);
tf1.setInputVerifier(new PassVerifier());

JTextField tf2 = new JTextField ("TextField2");
getContentPane().add (tf2, BorderLayout.SOUTH);

WindowListener l = new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
};
addWindowListener(l);
}

class PassVerifier extends InputVerifier {
public boolean verify(JComponent input) {
JTextField tf = (JTextField) input;
return "pass".equals(tf.getText());
}
}

public static void main(String[] args) {
Frame f = new VerifierTest();
f.pack();
f.setVisible(true);
}
}



Output