I'm new to java and part of our assignment is to build a GUI and display a result set from data input. I'm stuck at how to get the user's input from JTextFields and combobox selection and display those values to a table. My code is something like this. Thanks in advance.

import java.awt.FlowLayout;
import javax.swing.*;
import java.awt.GridLayout;

public class RetailCalculatorProject extends JFrame
{
    //components
    JPanel panel1 = new JPanel();
    JLabel iName = new JLabel ("Item Name");

JPanel panel2 = new JPanel();
JLabel iOrigPrice = new JLabel("Original Price $ ");

JPanel panel3 = new JPanel();
JLabel percentD = new JLabel ("Percent Discount ");


JPanel panel4 = new JPanel();
JLabel selectDepartmentLabel = new JLabel("Select Department");

JPanel panel5 = new JPanel();
String[] departments = {"Bath" , "Bedroom" , "Garden/Patio", "Kitchen", "Living Room"};
JComboBox option = new JComboBox(departments);

JPanel buttonsPanel = new JPanel();
JButton calculateButton = new JButton("Calculate");
JButton exitButton = new JButton("Exit");
CalculateButton cb = new CalculateButton();
ExitButton eb  = new ExitButton();


public RetailCalculatorProject()
{
    super ("Retail Calculator");

    setSize(550, 300);
    setLocationRelativeTo(null);
    GridLayout layout = new GridLayout(7, 1, 3, 3);
    setLayout(layout);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    setLookAndFeel();

}
private void setLookAndFeel()
{
    try
    {
        UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");

    }
    catch(Exception exc)
    {
        //ignore error
    }

 }
{
    FlowLayout row1 = new FlowLayout (FlowLayout.LEFT, 10, 10);
    setLayout(row1);
    panel1.add(iName);
    JTextField itemName = new JTextField(20);
    panel1.add(itemName);
    add(panel1);
}

{
    FlowLayout row2 = new FlowLayout(FlowLayout.LEFT, 10, 10);
    setLayout(row2);
    panel2.add(iOrigPrice);
    JTextField oP = new JTextField (4);
    panel2.add(oP);
    add(panel2);

}
{
    panel3.add(percentD);
    JTextField discount = new JTextField (3);
    panel3.add(discount);
    add(panel3);
}

{
    panel4.add(selectDepartmentLabel);
    add(panel4);
}

{
    panel5.add(option);
    add(panel5);
}

{   
    buttonsPanel.add(calculateButton);
    calculateButton.addActionListener(cb);
    buttonsPanel.add(exitButton);
    exitButton.addActionListener(eb);
    add(buttonsPanel);        
}


public static void main(String[] args) {
    //create an instance of the RetailCalculatorProject to apply members
    RetailCalculatorProject assignment = new RetailCalculatorProject();

}

}