I've written a code for JButton handeling.The code is=
import javax.swing.*;
import java.awt.*;
import java.util.Calendar;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
// Example using defaultButton and JRootPane.setDefaultButton()
public class DefaultButtonExample {
public static void main(String[] args) {
// Create some buttons
JButton ok = new JButton("OK");
JButton cancel = new JButton("Cancel");
JPanel buttonPanel = new JPanel();
buttonPanel.add(ok);
buttonPanel.add(cancel);
Calendar cl=Calendar.getInstance();
int i=cl.get(Calendar.YEAR);
int j=cl.get(Calendar.MONTH);
String a="001";
i=i%100;
String p=Integer.toString(i);
String q=Integer.toString(j);
if(p.length()==1)
p=0+p;
if(q.length()==1)
q=0+q;
String r=p+q+a;
public void actionPerformed(ActionEvent ae){
String str=ae.getActionCommand();
if(str.equals("ok"))
{
int b=Integer.parseInt(a);
b++;
String a1=Integer.toString(b);
if(a1.length()==1)
a1=00+a1;
if(a1.length()==2)
a1=0+a1;
r=p+q+a1;
JLabel msg = new JLabel("visitor ID="+r, JLabel.CENTER);
// Create a frame, get its root pane, and set the "ok" button as the
// default. This button will be "pressed" if we hit <ENTER> while the
// frame has focus.
JFrame f = new JFrame();
//f.addWindowListener(new BasicWindowMonitor());
JRootPane root = f.getRootPane();
root.setDefaultButton(ok);
// Layout and Display
Container content = f.getContentPane();
content.setLayout(new BorderLayout());
content.add(msg, BorderLayout.CENTER);
content.add(buttonPanel, BorderLayout.SOUTH);
f.setSize(200,100);
f.setVisible(true);
}
}But getting the following errors while compiling it.
