How to make FileChooser only have a Folder to choose?PLs help

Question

Dear Java expert!!Anyone know how to make user to choose it content from a single folder only...Pls advice
this is my program..
`````````````````````````
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
import java.util.*;
import java.net.*;
public class Test2 extends JFrame {
     JFileChooser chooser = new JFileChooser();
     TextPreviewer previewer = new TextPreviewer();
     JPanel previewPanel = new PreviewPanel();
     class PreviewPanel extends JPanel {
          public PreviewPanel() {
               JLabel label = new JLabel("Text Previewer",
                                             SwingConstants.CENTER);
               setPreferredSize(new Dimension(250,0));
               setBorder(BorderFactory.createEtchedBorder());
               setLayout(new BorderLayout());
               label.setBorder(BorderFactory.createEtchedBorder());
               add(label, BorderLayout.NORTH);
               add(previewer, BorderLayout.CENTER);
     public Test2() {
          super("Accessory Components");
          Container contentPane = getContentPane();
          JButton     button = new JButton("Select A File");
          contentPane.setLayout(new FlowLayout());
          contentPane.add(button);          
          chooser.setAccessory(previewPanel);
          chooser.addPropertyChangeListener(
                                             new PropertyChangeListener() {
               public void propertyChange(PropertyChangeEvent e) {
                    if(e.getPropertyName().equals(
                         JFileChooser.SELECTED_FILE_CHANGED_PROPERTY))
                         previewer.update((File)e.getNewValue());
          button.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    chooser.showOpenDialog(null);
     public static void main(String a[]) {
          JFrame f = new Test2();
          f.setBounds(300, 300, 300, 75);
          f.setVisible(true);
          f.setDefaultCloseOperation(
                                        WindowConstants.DISPOSE_ON_CLOSE);
          f.addWindowListener(new WindowAdapter() {
               public void windowClosed(WindowEvent e) {
                    System.exit(0);
class TextPreviewer extends JComponent {
     private ImageIcon icon;
     private JTextArea textArea = new JTextArea();
     public TextPreviewer() {
          setBorder(BorderFactory.createEtchedBorder());
          setLayout(new BorderLayout());
          add(new JScrollPane(textArea), BorderLayout.CENTER);
     public void update(File file) {
          textArea.setText(contentsOfFile(file));
          if(isShowing()) {
               textArea.revalidate();
     static String contentsOfFile(File file) {
          String s = new String();
          char[] buff = new char[50000];
          InputStream is;
          InputStreamReader reader;
          URL url;
          try {
               reader = new FileReader(file);
               int nch;
               while ((
                    nch = reader.read(buff, 0, buff.length)) != -1) {
                    s = s + new String(buff, 0, nch);
          catch (java.io.IOException ex) {
               s = "Could not load file";
          return s;

Answer 1

If you need to use a JFileChooser to select a folder, not a file, use:
JFileChooser jf = new JFileChooser();
jf.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
Now, your file chooser is a directory chooser....