Open local Folder using Applet Problem

Question

Deal all,
This problem is a real torment to me. Why I could run the code by appletviewer. And I could open local folder. But I try to open one webpage including this applet code, I could not run the same function. Please tell me how should I solve it. It is a Applet Security problem? Even I change my web Server java.policy, it is still not workable. How should I verify java.policy when user run applet?
<<my code>>
==========================
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.lang.*;
import java.applet.*;
public class FileSelectApplet extends Applet{
     Button btn = new Button("Choice");
     File name;
     Label lb = new Label("Please Input File List");
     TextField enter = new TextField("c:\\", 20);
     TextArea output = new TextArea(20, 30);
     public void init() {
          resize(400, 400);
          setLayout(new BorderLayout());
          // Create one Panel with Label/TextField/Button
          Panel pl = new Panel();
          pl.add(lb);
          pl.add(enter);
          btn.addActionListener(new btnListener());
          pl.add(btn);
          add("North", pl);
          add("Center", output);          
     class btnListener implements ActionListener {
          public void actionPerformed(ActionEvent e) {
               if (e.getActionCommand() == "Choice") {
                    output.setText(enter.getText());
                    name = new File(enter.getText());
                    if (name.exists()) {                         
                         output.append(
                                             name.getName() + " exists\n" +
                                             (name.isFile() ? "is a file\n" :
                                                                 "is not a file\n") +
                                             (name.isDirectory() ? "is a directory\n" :
                                                                           "is not a directory\n") +
                                             (name.isAbsolute() ? "is absolute path\n" :
                                                                      "is not absolute path\n") +
                                             "Last modified: " + name.lastModified() +
                                             "\nLength: " + name.length() +
                                             "\nPath: " + name.getPath() +
                                             "\nAbsolute path: " + name.getAbsolutePath() +
                                             "\nParent: " + name.getParent());
                         if (name.isFile()) {
                              try {
                                   RandomAccessFile r = new RandomAccessFile(name, "r");
                                   output.append("\n\n");
                                   do {
                                        output.append(r.readLine() + "\n");
                                   } while (r.getFilePointer() < r.length());
                              catch (IOException ioe) {
                              } // end of try
                         else if (name.isDirectory()) {
                              String dir[] = name.list();
                              output.append("\n\nDirectory contents:\n");
                              for (int i = 0; i < dir.length; i++)
                                   output.append(dir[i] + "\n");
                         } // end of (name.isFile())                         
                    else {
                              output.append(enter.getText() + "does not exists\n");
                              //output.appendText(enter.paramString() + "does not exists\n");
                    } // end of (name.exists())                    
               } // end of if                    
          } // end of actionPerformed
     } // end of btnListener     
==========================

Answer 1

Yes, that is security problem.
Apllet can't get access to any local resource.
To solve that problem you must sign applet or edit "local" policy file.