java第五次作业

 1 import javax.swing.*;
 2 import java.awt.*;
 3 import java.io.File;
 4 
 5 public class FileUtil extends JFrame{
 6 
 7     /**
 8      * @param args
 9      */
10     
11     public static String listDirectory(File dir) throws IllegalAccessException{
12         if(!dir.exists()){
13             throw new IllegalAccessException("目录"+dir+"不存在");
14         }
15         if(!dir.isDirectory()){//判断是不是目录
16             throw new IllegalArgumentException(dir+"不是目录");
17         }
18         String[] fileName = dir.list();    
19         String name ="";
20         for(String a : fileName){
21             name=name+a+"
";}
22         return name;
23         }
24     
25     public static void main(String[] args) {
26         // TODO Auto-generated method stub
27         JFrame frame=new JFrame();
28         JPanel main_panel =new JPanel(new BorderLayout());
29         JLabel label = new JLabel("FileList");
30         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
31         //frame.setLayout(null);
32         String[] itme =new String[]{"文件夹A","文件夹B"};
33         JComboBox box=new JComboBox();
34         for(int i=0;i<itme.length;i++){
35             box.addItem(itme[i]);
36         }
37         box.setEnabled(true);
38         box.setEditable(true);
39         box.setMaximumRowCount(6);
40         box.setBounds(230,30,130,25);
41             
42         frame.setBounds(400,300,400,200);
43         frame.setVisible(true);
44         JTextArea main_text =new JTextArea();
45          main_text.setBackground(Color.red);
46         JScrollPane AA=new JScrollPane();
47         AA.setViewportView(main_text);
48         main_text.setEnabled(false);
49         main_panel.add(box,BorderLayout.NORTH);
50         main_panel.add(AA,BorderLayout.CENTER);
51         main_panel.add(label,BorderLayout.SOUTH);
52         frame.add(main_panel);
53         
54         try {
55             String str=FileUtil.listDirectory(new File("C:\Users\woshinibaba\Desktop\Java作业5\soundPlayer"));
56             main_text.setText(str);
57         }
58         catch (IllegalAccessException e) {
59             // TODO Auto-generated catch block
60             e.printStackTrace();
61         }
62         
63 
64         
65         frame.setBounds(400,200,200,200);
66         frame.setVisible(true);
67         
68     
69     }
70 }