Criar um bowser para navegar em diretorios com Swing

/**
 * DirectoryPicker.java
 */
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.TitledBorder;
import javax.swing.filechooser.FileSystemView;

/**
 * Componente visual para entrada de nomes de diretórios. 
 * 
 * <pre>
 * +--Title----------------------+
 * | [directory name     ] [...] |
 * +-----------------------------+
 * </pre>
 */
public class DirectoryPicker extends JPanel {

    public DirectoryPicker() {
        super();
        initialize();
    }

    public String getApproveButtonText() {
        return approveButtonText;
    }

    public String getDialogTitle() {
        return dialogTitle;
    }

    public File getDirectory() {
        if (directory == null)
            directory = new File(".");
        return directory;
    }

    public String getTitle() {
        return title;
    }

    public void initialize() {
        setLayout(new BorderLayout());
        add(getTxtDirectory(), BorderLayout.CENTER);
        add(getBtnBrowse(), BorderLayout.EAST);
        border = new TitledBorder("");
        setBorder(border);
    }

    /**
     * Se este método não for chamado, o texto que aparece é "Open"
     * 
     * @param approveButtonText
     */
    public void setApproveButtonText(String approveButtonText) {
        this.approveButtonText = approveButtonText;
    }

    /**
     * Se este método não for chamado, o texto que aparece é "Open"
     * 
     * @param dialogTitle
     */
    public void setDialogTitle(String dialogTitle) {
        this.dialogTitle = dialogTitle;
    }

    /**
     * Seta o diretório
     * 
     * @param directory
     */
    public void setDirectory(File directory) {
        this.directory = directory;
        txtDirectory.setText(directory.getAbsolutePath());
    }

    public void setTitle(String title) {
        this.title = title;
        border.setTitle(title);
        this.repaint(); // isto é porque a borda só é redesenhada se isto tudo também for
    }

    private JButton getBtnBrowse() {
        if (btnBrowse == null) {
            btnBrowse = new JButton();
            btnBrowse.setText("...");
            btnBrowse.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    JFileChooser jfc = null;
                    File defaultFile = null;
                    if (txtDirectory.getText().trim().length() == 0) {
                        // Empty
                        File[] roots = FileSystemView.getFileSystemView().getRoots();
                        if (roots.length > 0) {
                            defaultFile = roots[0];
                        }
                    } else {
                        // Something was input, try finding it
                        try {
                            defaultFile = new File(txtDirectory.getText().trim()).getCanonicalFile();
                        } catch (IOException ex) {
                        }
                    }
                    if (defaultFile == null) {
                        jfc = new JFileChooser();
                    } else {
                        jfc = new JFileChooser(defaultFile);
                    }
                    if (dialogTitle != null)
                        jfc.setDialogTitle(dialogTitle);
                    jfc.setMultiSelectionEnabled(false);
                    jfc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
                    if (jfc.showDialog(DirectoryPicker.this, approveButtonText) == JFileChooser.APPROVE_OPTION) {
                        directory = jfc.getSelectedFile();
                        String path = directory.getPath();
                        txtDirectory.setText(path);
                        txtDirectory.setToolTipText(path);
                    }
                }
            });
        }
        return btnBrowse;
    }

    private JTextField getTxtDirectory() {
        if (txtDirectory == null) {
            txtDirectory = new JTextField();
        }
        return txtDirectory;
    }

    private String approveButtonText; 
    private TitledBorder border;
    private JButton btnBrowse;
    private String dialogTitle;
    /**
     * Selected directory
     */
    private File directory; 
    /**
     * Title
     */
    private String title;
    private JTextField txtDirectory;
}

import java.awt.BorderLayout;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class ExemploUsoDirectoryPicker extends JFrame {

    private static final long serialVersionUID = 1L;
    private JPanel jContentPane = null;
    private JLabel jLabel = null;
    private DirectoryPicker dirPicker = null;

    private DirectoryPicker getDirPicker() {
        if (dirPicker == null) {
            dirPicker = new DirectoryPicker();
        }
        return dirPicker;
    }
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                ExemploUsoDirectoryPicker thisClass = new ExemploUsoDirectoryPicker();
                thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                thisClass.setVisible(true);
            }
        });
    }
    public ExemploUsoDirectoryPicker() {
        super();
        initialize();
    }
    private void initialize() {
        this.setSize(450, 100);
        this.setContentPane(getJContentPane());
        this.setTitle("Exemplo de Uso - DirectoryPicker");
        getDirPicker().setTitle("Diretório de saída");
        getDirPicker().setDialogTitle("Escolha o diretório de saída");
        getDirPicker().setApproveButtonText("Escolher");
    }
    private JPanel getJContentPane() {
        if (jContentPane == null) {
            jLabel = new JLabel();
            jLabel.setText("Clique no botão \"...\" para escolher um nome de diretório");  
            jContentPane = new JPanel();
            jContentPane.setLayout(new BorderLayout());
            jContentPane.add(jLabel, BorderLayout.NORTH);  
            jContentPane.add(getDirPicker(), BorderLayout.CENTER);  
        }
        return jContentPane;
    }
}