（1）首先使用Fire中的isDirectory方法提取文件中的内容，获得目录下的文件并输出。然后用JList方法输入到列表中。显示出来

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Toolkit;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.File;

import java.util.ArrayList;

import java.util.List;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JList;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JSlider;

import javax.swing.border.EmptyBorder;

import javax.swing.event.ChangeEvent;

import javax.swing.event.ChangeListener;

public class Main extends JFrame {

/**

* @param args

*/

static final String VERSION = "Version 1.0";

private static final String AUDIO_DIR = "audio";

private JList fileList;    private JSlider slider;    private JLabel infoLabel;        public Main()    {        super("name");        String[] FileNames = findFiles(AUDIO_DIR, null);        makeFrame(FileNames);    }    private String[] findFiles(String dirName, String suffix)    {        File dir = new File(dirName);        if(dir.isDirectory()) {            String[] allFiles = dir.list();            if(suffix == null) {                return allFiles;            }            else {                List
    
      selected = new ArrayList
     
      ();                for(String filename : allFiles) {                    if(filename.endsWith(suffix)) {                        selected.add(filename);                    }                }                return selected.toArray(new String[selected.size()]);            }        }        else {            System.out.println("Error: " + dirName + " must be a directory");            return null;        }    }    private void makeFrame(String[] Files)    {        setDefaultCloseOperation(EXIT_ON_CLOSE);                JPanel contentPane = (JPanel)getContentPane();        contentPane.setBorder(new EmptyBorder(0,0,0,0));        contentPane.setLayout(new BorderLayout(8,8));        JPanel Pane = new JPanel();        {            Pane.setLayout(new BorderLayout(4, 4));            fileList = new JList(Files);            fileList.setForeground(new Color(140,171,226));            fileList.setBackground(new Color(0,0,0));            fileList.setSelectionBackground(new Color(87,49,134));            fileList.setSelectionForeground(new Color(140,171,226));            JScrollPane scrollPane = new JScrollPane(fileList);            scrollPane.setColumnHeaderView(new JLabel("fileList"));           Pane.add(scrollPane, BorderLayout.CENTER);        }        contentPane.add(Pane, BorderLayout.CENTER);        pack();                Dimension d = Toolkit.getDefaultToolkit().getScreenSize();        setLocation(d.width/2 - getWidth()/2, d.height/2 - getHeight()/2);        setVisible(true);    }public static void main(String[] args) {     Main gui = new Main();}
     
    

}

（2）这个只是在了解代码的基础上稍作修改的，还不够完善。