import java.awt.BorderLayout;
import javax.swing.InputVerifier;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class MainClass {
public static void main(String args[]) {
JFrame frame = new JFrame("Verifier Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textField1 = new JTextField();
JTextField textField2 = new JTextField();
JTextField textField3 = new JTextField();
InputVerifier verifier = new InputVerifier() {
public boolean verify(JComponent comp) {
boolean returnValue;
JTextField textField = (JTextField) comp;
try {
Integer.parseInt(textField.getText());
returnValue = true;
} catch (NumberFormatException e) {
returnValue = false;
}
return returnValue;
}
};
textField1.setInputVerifier(verifier);
textField3.setInputVerifier(verifier);
frame.add(textField1, BorderLayout.NORTH);
frame.add(textField2, BorderLayout.CENTER);
frame.add(textField3, BorderLayout.SOUTH);
frame.setSize(300, 100);
frame.setVisible(true);
}
}