Java五

import java.awt.Color;
import java.awt.BorderLayout;
import java.io.File;
import java.awt.Container;
import java.awt.event.ActionEvent;
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.JTextArea;


public class FileUtils extends JFrame{
/**
 * 列出指定文件夹（目录）中的所有文件或目录的名额
 * @param dri File类型指定的文件夹（目录）
 * @throws IllegalAccessException 
 */
  public static String listDirectory(File dir) throws IllegalAccessException{
      if(!dir.exists()){
    throw new IllegalAccessException("目录"+dir+"不存在");
      }
      
      //判断dir下关联的文件和目录是否存在
      if(!dir.isDirectory()){
          //如果不存在抛出异常
          throw new IllegalAccessException(dir + "不是目录");
      }
      String[] fileName = dir.list();
      String name ="";
      for(String a : fileName){
          name=name+a+"
";}
       return name;
      }
     
/**
 * @param args
 */
public static void main(String[] args) {
    // TODO Auto-generated method stub
     // TODO Auto-generated method stub
    JFrame frame=new JFrame();
    JPanel main_panel =new JPanel(new BorderLayout());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    //frame.setLayout(null);
    String[] itme =new String[]{".jpg",".zip",".doc"};
    JComboBox box=new JComboBox();
    for(int i=0;i<itme.length;i++){
        box.addItem(itme[i]);
    }
    box.setEnabled(true);
    box.setEditable(true);
    box.setMaximumRowCount(6);
    box.setBounds(230,30,130,25);
 
     
    frame.setBounds(400,300,400,200);
    frame.setVisible(true);
    JTextArea main_text =new JTextArea();
    main_text.setBackground(Color.BLACK);
    JScrollPane AA=new JScrollPane();
    AA.setViewportView(main_text);
    main_text.setEnabled(false);
    main_panel.add(box,BorderLayout.NORTH);
    main_panel.add(AA,BorderLayout.CENTER);
    frame.add(main_panel);
     
    
    
    try {
        String str=FileUtils.listDirectory(new File("C:\Users\Administrator\Desktop\Java作业5\soundPlayer\audio"));
        main_text.setText(str);
    }
    catch (IllegalAccessException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
frame.setBounds(300,400,300,400);
frame.setVisible(true);

}

}