How To Use ActionListeners

I'm trying to learn how to use ActionListeners. I want a button to hold a int and everytime it's pressed, the int gets + 2. Basically the button is a product and everytime it's pressed, you buy it, the int is your total, at least for that button. I want to have several buttons, each a different price, so maybe button 2 is +3 everytime. At the end then I want to add all the ints together for a total cost and then write that to a file. The only thing is I'm having trouble.

Here's my code

import javax.swing.*;
import java.awt.*;
public class Shop
{
public static void main(String [] args)
{
Frame frame = new Frame();
Button button = new Button(frame.getPanel());

[code]...

The problem is in my Button class, I think it's because my actionPerformed is set to void, but when I change it to int, it says my class must be abstract. For the moment I only have the info going to a label, this is just for testing. Whenever I run it, it says Juice is set to 0, probably because like I said earlier, it's set to void.