Problem in Uploading a File by Applet

Question

Hi Members,
* I have faced problem while uploading a file from client to server by ftp protocol using APPLET(No JSP) only
* I am getting exception while running....
* My source code is as follows,
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class UploadAndDownload extends Applet implements ActionListener {
     Button upload;
     Button browse;
     TextField filename;
     File source = null;
     Label name;
     StringBuffer sb;
     BufferedInputStream bis = null;
     BufferedOutputStream bos = null;
     public void init() {
          setLayout(new FlowLayout());
          upload = new Button("Upload");
          browse = new Button("Browse");
          name = new Label("Filename");
          filename = new TextField("", 45);
          add(name);
          add(filename);
          add(upload);
          add(browse);
          upload.addActionListener(this);
          browse.addActionListener(this);
     public void actionPerformed(ActionEvent evt) {
          // Code for browsing a file
          String input_file_name = "";
          if (evt.getSource() == browse)
               Frame parent = new Frame();
               FileDialog fd = new FileDialog(parent, "Select a file", FileDialog.LOAD);
               fd.setVisible(true);
               input_file_name = fd.getFile();
               filename.setText(input_file_name);
               // Gets the file from the file dialog and assign it to the source
               source = new File(input_file_name);
               repaint();
          // Code for Uploading a file to the server
          if (evt.getSource() == upload) {
               // Appending the server pathname in string buffer
               sb = new StringBuffer("ftp://");
               sb.append("2847");
               sb.append(':');
               sb.append("Websphere25");
               sb.append("@");
               sb.append("172.16.1.111");
               sb.append('/');
               sb.append(input_file_name);
               sb.append(";type=i");
               try {
                    URL url = new URL(sb.toString());
                    URLConnection urlc = url.openConnection();
                    bos = new BufferedOutputStream(urlc.getOutputStream());
                    bis = new BufferedInputStream(new FileInputStream(source));
                    int i;
                    // Read from the inputstream and write it to the outputstream
                    while ((i = bis.read()) != -1) {
                         bos.write(i);
               } catch (MalformedURLException e) {
                    e.printStackTrace();
               } catch (IOException e) {
                    e.printStackTrace();
               } finally {
                    if (bis != null)
                         try {
                              bis.close();
                         } catch (IOException ioe) {
                              ioe.printStackTrace();
                    if (bos != null)
                         try {
                              bos.close();
                         } catch (IOException ioe) {
                              ioe.printStackTrace();
MY EXCEPTION IS,
Exception in thread "AWT-EventQueue-2" java.security.AccessControlException: access denied (java.net.SocketPermission 172.16.1.111:80 connect,resolve)
     at java.security.AccessControlContext.checkPermission(Unknown Source)
     at java.security.AccessController.checkPermission(Unknown Source)
     at java.lang.SecurityManager.checkPermission(Unknown Source)
     at java.lang.SecurityManager.checkConnect(Unknown Source)
     at sun.net.www.http.HttpClient.openServer(Unknown Source)
     at sun.net.www.http.HttpClient.<init>(Unknown Source)
     at sun.net.www.http.HttpClient.New(Unknown Source)
     at sun.net.www.http.HttpClient.New(Unknown Source)
     at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
     at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
     at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
     at sun.net.www.protocol.ftp.FtpURLConnection.connect(Unknown Source)
     at sun.net.www.protocol.ftp.FtpURLConnection.getOutputStream(Unknown Source)
     at UploadAndDownload.actionPerformed(UploadAndDownload.java:68)
     at java.awt.Button.processActionEvent(Unknown Source)
     at java.awt.Button.processEvent(Unknown Source)
     at java.awt.Component.dispatchEventImpl(Unknown Source)
     at java.awt.Component.dispatchEvent(Unknown Source)
     at java.awt.EventQueue.dispatchEvent(Unknown Source)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.run(Unknown Source)* Please let me know what problem in my code....
* Thanks in advance....

Answer 1

* Thanks for your reply....
* I have signed my policy file by giving AllPermission and mentioned in java.security file in bin folder....
* My question is , by giving AllPermission , can we access and do all permissions like ( SecurityPermission, AWTPermission, SocketPermission, NetPermission, FilePermission, SecurityPermission etc )...
* My policy file is looks like follow,
/* AUTOMATICALLY GENERATED ON Tue Apr 16 17:20:59 EDT 2002*/
/* DO NOT EDIT */
grant {
  permission java.security.AllPermission;
};* If i signed the policy like above, and when i run the applet file in InternetExplorer now , it thorws the following exception on my console,
java.net.ProtocolException: cannot write to a URLConnection if doOutput=false - call setDoOutput(true)
     at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)
     at sun.net.www.protocol.ftp.FtpURLConnection.getOutputStream(Unknown Source)
     at UploadAndDownload.actionPerformed(UploadAndDownload.java:68)
     at java.awt.Button.processActionEvent(Unknown Source)
     at java.awt.Button.processEvent(Unknown Source)
     at java.awt.Component.dispatchEventImpl(Unknown Source)
     at java.awt.Component.dispatchEvent(Unknown Source)
     at java.awt.EventQueue.dispatchEvent(Unknown Source)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
     at java.awt.EventDispatchThread.run(Unknown Source)* Please let me know , how to solve this and give me your suggestion on the above process...
* Thanks in advance...
Regards,
JavaImran