Apache Commons FTP problems

Question

I want to implement a FTP Client with Apache Commons Net only for uploading data. The Connection and Login to FTP-Server works fine. But the upload does not work right. The files are a little to big as the originals. And the files are damaged. I tried an image, a video and a textfile. Only the textfile is alright.

Now I see while debugging

boolean tmp=client.setFileTransferMode(FTPClient.BINARY_FILE_TYPE);

gives me false. So it can not be set. Why? (Maybe this is not the problem?)

Here a the rest of my code

client=new FTPClient();

    try {           
        int reply;
        client.connect(url, port);
        reply = client.getReplyCode();

        if (!FTPReply.isPositiveCompletion(reply))
        {
            client.disconnect();
            System.err.println("FTP server refused connection.");
            System.exit(1);
        }


        client.login(user, pw);
        boolean xxx=client.setFileTransferMode(FTPClient.BINARY_FILE_TYPE);
        client.setControlKeepAliveTimeout(300);
        client.enterLocalPassiveMode();

if (client.isConnected())
    {
    try {
        File file=new File(<FILE>);
        FileInputStream inputStream = new FileInputStream(file);
        OutputStream outputStream = client.storeFileStream(file.getName());

          byte[] buffer = new byte[4096];
          int l;
       while((l = inputStream.read(buffer))!=-1)
               {
                outputStream.write(buffer, 0, l);
            }

          inputStream.close();
          outputStream.flush();
          outputStream.close();}

Answer 1

If only the text file was transferred successfully, I suspect you need to set the binary transfer file type.

See the setFileType method to see how to do this.

The commons-net wiki mentions this is the cause of most file corruption issues.

Answer 2

Change the following:

boolean xxx=client.setFileTransferMode(FTPClient.BINARY_FILE_TYPE);

Should be:

boolean xxx=client.setFileType(FTP.BINARY_FILE_TYPE);

You have confused FileTransferModes with FileTypes.

The available FileTypes are:

• FTP.ASCII_FILE_TYPE (default)
• FTP.BINARY_FILE_TYPE
• FTP.EBCDIC_FILE_TYPE
• FTP.LOCAL_FILE_TYPE

The available FileTransferModes are:

• FTP.STREAM_TRANSFER_MODE (default)
• FTP.BLOCK_TRANSFER_MODE
• FTP.COMPRESSED_TRANSFER_MODE

I suppose if apache introduced enums for these constant types, then this kind of problem could be avoided, but then the library would not be available to pre-java-5 runtimes.
I wonder how much of an issue java 1.4 compatibility really is.