第五次作业

（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<String> selected = new ArrayList<String>();
                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。