How To Split JFrame As Parent Class With ActionListener / ItemListener

I'm working on a program using GUI. My problem is that I'm reaching **1000 Line** and this is stressful because all my code are in one file. I'm not liking this. So I research the internet about Inheritance. However, what I know about Inheritance that Inherit everything in the parent class. However, when I try to use a variables in the child class to override it in the parent class I can't for example let say that I have in the parent class something like this:

JButton getButton = new JButton("Enter");

Now when I go to the child class. I want to Inherit and use this variable so I can use the ActionListener on the getButton and override for the parent class, but it's not working.

This is my code:
 
public class H_Store extends JFrame {
private String s ="Kinds: ";
private JButton calculateButton;
private JPanel mainPane;
private JPanel getProfitPanel;
private JTextField ground_M_QTextField;

[Code] ....

What I want to do exactly is to take the last code into another class or do something with it so I can use it in the Parent class, in other word any math calculation method or class I want them outside the Parent class. I mean this code :

private class CalcButtonListener implements ActionListener{ 
// vairbles for the ground Meat check box
private double total_GM;
private double weightPrice_1;
private String stringQ;
private String stringW;
private String stringP;

[Code] ....