第五次作业

import java.awt.;
import java.awt.event.;

import javax.swing.;
import javax.swing.event.;
import javax.swing.border.*;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

import java.io.*;

/**

A simple sound player. To start, create an instance of this class.
The sound player can play sound clips in WAV, AU and AIFF formats
with standard sample rates.
@author Michael Kolling and David J Barnes
@version 1.0
*/
public class SoundPlayerGUI extends JFrame
implements ChangeListener, ActionListener
{

private final String AUDIO_DIR = "audio";

private JList fileList;

/**
- Main method for starting the player from a command line.
  */
  public static void main(String[] args)
  {
  SoundPlayerGUI gui = new SoundPlayerGUI();
  }
/**
- Create a SoundPlayer and display its GUI on screen.
  */
  public SoundPlayerGUI()
  {
  super("SoundPlayer");
  
  String[] audioFileNames = findFiles(AUDIO_DIR, null);
  makeFrame(audioFileNames);
  }
/**
- Play the sound file currently selected in the file list. If there is no
- selection in the list, or if the selected file is not a sound file,
- do nothing.
  */
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;
}
}

// ------- ChangeListener interface (for Slider) -------

/**
- ChangeListener method for slider changes. This method is called
- when the slider value is changed by the user.
- @param evt The event details.
  */
private void makeFrame(String[] audioFiles)
{
// the following makes sure that our application exits when
// the user closes its window
```
 JPanel contentPane = (JPanel)getContentPane();


 
 // Specify the layout manager with nice spacing
 contentPane.setLayout(new BorderLayout(8, 8));

 // Create the left side with combobox and scroll list
 JPanel leftPane = new JPanel();
 {
     leftPane.setLayout(new BorderLayout(8, 8));

  

     // Create the combo box.
   
     

     // Create the scrolled list for file names
     fileList = new JList(audioFiles);
     fileList.setForeground(new Color(140,171,226));
     fileList.setBackground(new Color(1,0,0));
     fileList.setSelectionBackground(new Color(87,49,134));
     fileList.setSelectionForeground(new Color(140,171,226));
     JScrollPane scrollPane = new JScrollPane(fileList);
     scrollPane.setColumnHeaderView(new JLabel("Audio files"));
     leftPane.add(scrollPane, BorderLayout.CENTER);
 }
 contentPane.add(leftPane, BorderLayout.CENTER);

 // Create the center with image, text label, and slider

 pack();
 
 // place this frame at the center of the screen and show
 Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
 setLocation(d.width/2 - getWidth()/2, d.height/2 - getHeight()/2);
 setVisible(true);
```
}

@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub

}

@Override
public void stateChanged(ChangeEvent arg0) {
// TODO Auto-generated method stub

}

}

import java.awt.BorderLayout;
import java.awt.Color;
import java.io.File;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;

public class FileUtils {

/**

列出指定目录下的所有文件和子目录的名称
@throws IllegalAccessException

*/
public static void listDirectory(File dir) throws IllegalAccessException{
//判断File对象dir是否存在，使用File类的exists()方法
if(!dir.exists()){
//如不存在，抛出异常
throw new IllegalAccessException("目录" + dir +"不存在");
}
//判断dir是否是目录，使用File类的isDirectory()方法
if(!dir.isDirectory()){
//如果dir不是目录，抛出异常
throw new IllegalArgumentException(dir + "不是目录");
}
//获得指定目录dir下的文件及子目录并输出（1.list();2.listFiles()）
//使用list()方法实现
String[] fileName = dir.list();
for(String s :fileName){
System.out.println(dir + ""+ s);
}

System.out.println();
//使用listFiles()方法实现只列出目录下的所有文件名称
File[] files = dir.listFiles();
for(File file:files){
//如果是文件，则输出
if(file.isFile()){
System.out.println(file);
}
}

JFrame a =new JFrame("Text");
a.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
a.setLayout(new BorderLayout());
String[] AA ={".txt",".ppt",".jpg",".docx"};
JComboBox l1=new JComboBox(AA);
a.add(l1,BorderLayout.NORTH);
JList list = new JList(files);
list.setForeground(new Color(140,200,220));
list.setSelectionBackground(new Color(100,80,150));
list.setSelectionForeground(new Color(140,200,220));
JScrollPane sp = new JScrollPane(list);
//
a.add(sp,BorderLayout.CENTER);
a.setBounds(400,300,400,300);

a.setVisible(true);
}
public static void main(String[] args) {
// TODO Auto-generated method stub

try {
FileUtils.listDirectory(new File("E:"));
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}