Doubt with JComboBox to enter data at runtime [closed]

I'm new to Swing and this is the first Java application I'm actually doing, however I'm doubtfully related to JComboBox because I'd like to do a field (JTextField) where I'd put the directory and click a button JButton) and send it to the JComboBox, that is, to enter data into the JComboBox at run time. Could someone give me a light?

PS: I'm doing an application where I create a directory by that program.

Follow the code: link

package view;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

import controller.ControleJavaEasyDirectory;

import javax.swing.JLabel;
import javax.swing.JOptionPane;

import java.awt.Font;
import java.awt.Frame;

import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.io.File;
import java.awt.event.ActionEvent;
import javax.swing.JList;
import javax.swing.JSpinner;
import javax.swing.JEditorPane;
import javax.swing.JFormattedTextField;
import javax.swing.JComboBox;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JMenuBar;
import org.eclipse.wb.swing.FocusTraversalOnArray;
import java.awt.Component;
import javax.swing.JMenu;
import javax.swing.JPopupMenu;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JScrollBar;
import javax.swing.ImageIcon;
import javax.swing.JMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.JTextPane;
import java.awt.List;
import java.awt.Button;
import javax.swing.JSeparator;

public class JanelaJavaEasyDirectory extends JFrame {

    private JPanel contentPane;
    private JTextField campoNomeDoArquivo;
    private ControleJavaEasyDirectory jed = new ControleJavaEasyDirectory();
    Frame janela2 = new Frame();

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    JanelaJavaEasyDirectory frame = new JanelaJavaEasyDirectory();
                    frame.setVisible(true);
                    frame.setLocationRelativeTo(null);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public JanelaJavaEasyDirectory() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 308);

        JMenuBar menuBar = new JMenuBar();
        setJMenuBar(menuBar);

        JMenu menuSistema = new JMenu("Sistema");
        menuBar.add(menuSistema);

        JMenuItem mntmDiretorio = new JMenuItem("Novo diret\u00F3rio");
        mntmDiretorio.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                janela2 = new Frame();
                janela2.setLocationRelativeTo(contentPane);
                janela2.setVisible(true);
                // janela2.setResizable(false);
            }
        });
        mntmDiretorio.setIcon(new ImageIcon(JanelaJavaEasyDirectory.class
                .getResource("/com/sun/javafx/scene/control/skin/caspian/fxvk-capslock-button.png")));
        menuSistema.add(mntmDiretorio);

        JMenuItem mntmSair = new JMenuItem("Sair");
        mntmSair.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(JFrame.EXIT_ON_CLOSE);
            }
        });

        JSeparator separator = new JSeparator();
        menuSistema.add(separator);
        mntmSair.setIcon(new ImageIcon(
                JanelaJavaEasyDirectory.class.getResource("/com/sun/java/swing/plaf/windows/icons/Error.gif")));
        menuSistema.add(mntmSair);
        contentPane = new JPanel();
        contentPane.setToolTipText("");
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel lblJavaEasyDirectory = new JLabel("Java Easy Directory");
        lblJavaEasyDirectory.setFont(new Font("Tahoma", Font.BOLD, 16));
        lblJavaEasyDirectory.setBounds(139, 50, 159, 17);
        contentPane.add(lblJavaEasyDirectory);

        JLabel lblDiretrio = new JLabel("Diret\u00F3rio:");
        lblDiretrio.setToolTipText("Selecione um diret\u00F3rio.");
        lblDiretrio.setFont(new Font("Tahoma", Font.PLAIN, 16));
        lblDiretrio.setBounds(35, 88, 75, 14);
        contentPane.add(lblDiretrio);

        JComboBox campoDiretorio = new JComboBox();
        campoDiretorio.setModel(new DefaultComboBoxModel(new String[] { "C:\Users\renan\Downloads\ISOs" }));
        campoDiretorio.setBounds(109, 87, 264, 20);
        contentPane.add(campoDiretorio);

        JLabel lblNomeDoArquivo = new JLabel("Nome da pasta:");
        lblNomeDoArquivo.setToolTipText("Insira o nome da pasta que deseja criar.");
        lblNomeDoArquivo.setFont(new Font("Tahoma", Font.PLAIN, 16));
        lblNomeDoArquivo.setBounds(51, 129, 135, 14);
        contentPane.add(lblNomeDoArquivo);

        campoNomeDoArquivo = new JTextField();
        campoNomeDoArquivo.setBounds(170, 128, 203, 20);
        contentPane.add(campoNomeDoArquivo);
        campoNomeDoArquivo.setColumns(10);

        JButton btnCriarDiretrio = new JButton("Criar diret\u00F3rio");
        btnCriarDiretrio.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {

                String nomeDirDesejado = (String) campoDiretorio.getSelectedItem();

                String nomePasta = campoNomeDoArquivo.getText();

                    File novaPasta = new File(nomeDirDesejado, nomePasta);
                    novaPasta.mkdir();

                    if (nomePasta.equals(""))
                        throw new IllegalArgumentException();
                    else
                        JOptionPane.showMessageDialog(null, "Diretório criado com sucesso!");


            }
        });
        btnCriarDiretrio.setBounds(152, 171, 126, 23);
        contentPane.add(btnCriarDiretrio);

        JLabel lblDesenvolvidoPorRenan = new JLabel("Desenvolvido por Renan Narciso");
        lblDesenvolvidoPorRenan.setBounds(125, 223, 185, 14);
        contentPane.add(lblDesenvolvidoPorRenan);

        JLabel lblV = new JLabel("v1.0 - 2017");
        lblV.setBounds(361, 223, 63, 14);
        contentPane.add(lblV);
        contentPane.setFocusTraversalPolicy(new FocusTraversalOnArray(new Component[] { lblJavaEasyDirectory,
                lblDiretrio, campoDiretorio, lblNomeDoArquivo, campoNomeDoArquivo, btnCriarDiretrio }));
    }

    private static void addPopup(Component component, final JPopupMenu popup) {
        component.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                if (e.isPopupTrigger()) {
                    showMenu(e);
                }
            }

            public void mouseReleased(MouseEvent e) {
                if (e.isPopupTrigger()) {
                    showMenu(e);
                }
            }

            private void showMenu(MouseEvent e) {
                popup.show(e.getComponent(), e.getX(), e.getY());
            }
        });
    }
}