InputVerifier

import java.awt.*;
import javax.swing.*;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class sri11
{
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);
}
}