JavaBean Problem

[Peter]

This code doesn't work, can you check it and then tell me the problem?

import java.util.*;
public class NumberEvent extends EventObject{
public int number1, number2;
public NumberEvent(Object o, int number1, int number2) {
super(o);
this.number1=number1;
this.number2=number2;
}
}

2/
import java.util.*;
public interface NumberEnteredListener extends EventListener{
public void arithmeticPerformed(NumberEvent mec);
}

3/ this code I used NetBeans IDE 5.0 to make
import java.io.Serializable;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class NumberBean extends javax.swing.JPanel implements ActionListener, Serializable{
public NumberBean() {
initComponents();
}
NumberEnteredListener me1;
public void addNumberListener(NumberEnteredListener me1){
this.me1=me1;
}
NumberEvent mec;
public void fireNumberEvent(NumberEvent mec){
me1.arithmeticPerformed(mec);
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource()==ok){
int f1=Integer.parseInt(tf1.getText());
int f2=Integer.parseInt(tf2.getText());
mec=new NumberEvent(ok, f1, f2);
fireNumberEvent(mec);
}
}

4/
import javax.swing.*;
public class ArithmeticPerformer extends JFrame implements NumberEnteredListener{
NumberBean meb;

/** Creates a new instance of ArithmeticPerformer */
public ArithmeticPerformer() {
super("Arithmetic Caculations");
meb=new NumberBean();
getContentPane().add(meb);
meb.addNumberListener(this);
}

public void arithmeticPerformed(NumberEvent mec){
int result=mec.number1+mec.number2;
String temp="The result of adding the numbers is : " + String.valueOf(result);
JOptionPane.showMessageDialog(this, temp);
}

public static void main(String arg[]){
ArithmeticPerformer mec=new ArithmeticPerformer();
mec.setSize(300, 300);
mec.setVisible(true);
}
}

I can start the UI but the calculation can not operate (The JOptionPane does not appear.).

Thanks.

[Ed]

Peter:
you forgot to call ok.addActionListener

[Ed]

I think that connection object is in null
check it