Problems uploading file to FTP

[Egil Poma]

I've got a zip file which work fine on my local file system. After I upload it to a FTP server, the file gets corrupted. It seems something gets appended to the file because the zip file is bigger after I've uploaded it.

When I try to unzip it after I've uploaded it says: error: invalid compressed data to inflate --> 77 extra bytes at beginning or within zipfile

I'm using the Jacarta Jacarta Commons Net FTP package to deal with the FTP server.

I can't figure this one out. Why does my code append data to the file when uploading it to the FTP?

Help!

Here's my code:

/**
 * Uploads a file via ftp.
 * 
 * @param file the file to store on the ftp server
 * @param fileName what to call the file one the ftp server
 * 
 * @throws NeSystemException if an error occurs
 * 
 * @see <a href="http://www.rfc-archive.org/getrfc.php?rfc=640" target="_blank" rel="nofollow">http://www.rfc-archive.org/getrfc.php?rfc=640</a> for ftp reply codes
 */
private void ftpUpload(File file, String fileName) throws NeSystemException {
 
String ftpServer = "something";
String ftpUsername = "something";
String ftpPassword = "something";
int ftpPort = "something";
 
FTPClient ftpClient = new FTPClient();
 
try {
InetAddress inetAddress = InetAddress.getByName(ftpServer);
ftpClient.connect(inetAddress, ftpPort);
 
// After connection attempt, you should check the reply code to verify success.
if (!FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
ftpClient.disconnect();
throw new NeSystemException("FTP server refused connection! Reply string from server is: "
+ ftpClient.getReplyString());
}
 
// Enter PASV mode because we are behind a firewall
ftpClient.enterLocalPassiveMode();
 
// Login
ftpClient.login(ftpUsername, ftpPassword);
 
// Upload file
InputStream fis = new FileInputStream(file);
OutputStream os = ftpClient.storeFileStream(fileName);
byte buf[] = new byte[8192];
while (fis.read(buf) != -1) {
os.write(buf);
}
fis.close();
os.close();
 
// Must call completePendingCommand() to finish upload command.
if (!ftpClient.completePendingCommand()) {
if (!ftpClient.logout()) {
if (log.isWarnEnabled()) {
log.warn("Failed to successfully logout from ftp server! Reply code: "
+ ftpClient.getReplyCode());
}
}
throw new NeSystemException("File transfer failed!");
}
 
if (!ftpClient.logout()) {
if (log.isWarnEnabled()) {
log.warn("Failed to successfully logout from ftp server! Reply code: " + ftpClient.getReplyCode());
}
}
} catch (Exception e) {
throw new NeSystemException("Error uploading to ftp server '" + ftpServer + "'!", e);
}  finally {
if (ftpClient.isConnected()) {
try {
ftpClient.disconnect();
} catch (IOException ioe) {
if (log.isWarnEnabled()) {
log.warn("Failed to disconnect from the ftp server!", ioe);
}
}
}
}
}

[Joe Ess]

Originally posted by Egil Poma:

Why does my code append data to the file when uploading it to the FTP?

Because you are telling it to. This code:

byte buf[] = new byte[8192];
while (fis.read(buf) != -1) {
    os.write(buf);
}    

always writes 8192 bytes to the output stream no matter how many bytes were read. You need to find out how many bytes were read in and only write that many out. Have a look at this example and let us know if it works or if you have any other questions.

[Egil Poma]

You are right, it was indeed the streams.

So I changed my upload code to this, and now it works:

// Upload file
InputStream in = new FileInputStream(file);
ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
boolean stored = ftpClient.storeFile(fileName ,in);
in.close();

I had ro remove the completePendingCommand() statement to make it work as well.

Thanks