JComboBox - Java (241591)

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
public class EShop {
private JTextField df;
    public void setDisplayValue(String val){
        df.setText(val);
    }
    public String getDisplayValue(){
        return df.getText();
 
    }
 
    public static void main(String[] args) {
 
        JPanel p1;
        JButton button0;
        JPanel esh = new JPanel();
        JTextField dfield;
        button0 = new JButton("Buy");
        p1 = new JPanel();
 
        String [] items1 = {
                "Bike Arlenok",
                "Bike Ukraine"
        };
 
        JComboBox comboBox = new JComboBox(items1);
 
        Integer [] items2 = {
                1,
                2,
                3,
                4,
                5,
                6,
                7,
                8,
                9,
                10,
                15,
                20,
                25,
        };
        JComboBox cb = new JComboBox(items2);
        JLabel label1 = new JLabel("Enter bike");
 
        JLabel label2 = new JLabel("how much");
        JTextField field = new JTextField(10);
 
        esh.add(label1);
        esh.add(comboBox);
        esh.add(label2);
        esh.add(cb);
        esh.add(button0);
        esh.add(field);
 
            p1 = new JPanel();
        GridLayout gl = new GridLayout(10,30);
        p1.setLayout(gl);
 
        JFrame frame = new JFrame("E-Shop");
        frame.setContentPane(esh);
        frame.setVisible(true);
        frame.setSize(250, 300);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
 
        ActionListener actionListener = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
 
            }
        };
        comboBox.addActionListener(actionListener);
        cb.addActionListener(actionListener);
        button0.addActionListener(actionListener);
 
    }
}