FTPClient - Java, upload file

问题:

I'm trying to do a VERY simple file upload. I want a Java FTPClient that can upload any file I tell it to. But the pdf always gets all messed up and my pdf editor (Adobe) won't open it, saying there is an I/O error.

I'm using the following class:

    import org.apache.commons.net.ftp.FTPClient;
    ....

    FTPClient client = new FTPClient();
    FileInputStream fis = null;

    try {
        client.connect("mydomain.com");
        client.login("user", "password");

        String filename = "myPDF.pdf";
        fis = new FileInputStream(filename);

        client.storeFile("temp.pdf", fis);
        fis.close();
        client.logout();
    } catch (IOException e) {
        e.printStackTrace();
    }

Why doesn't this work, and how do I fix it?

回答1:

It doesn't work because the default transfer mode for FTPClient is FTP.ASCII_FILE_TYPE. You just need to update the configuration to transfer in binary mode.

回答2:

Add this to your file

ftp.setFileType(FTP.BINARY_FILE_TYPE, FTP.BINARY_FILE_TYPE);
ftp.setFileTransferMode(FTP.BINARY_FILE_TYPE);

I had the same problem with xlsx files and this was a good solution.

回答3:

It's often forgotten that FTP has two modes of operation - one for text files and the other for binary (image) files. In the good old days, connecting from a command line ftp client, we'd carefully remember to set the transfer mode before requesting a file - or we'd run into exactly the sort of problem you seem to be having. Today a lot of situations seem to default to binary, but not apparently yours.

You probably need to tell your ftp implementation to transfer in binary/image mode.

回答4:

Try to use BufferedInputStream, this is a (working) code sample:

BufferedInputStream bis = new BufferedInputStream(new FileInputStream(f));
res = client.storeFile("File Name", bis);
bis.close();
client.logout();

回答5:

From documentation

This method does NOT close the given InputStream.

So close the FileInputStream before calling logout()

回答6:

Try this.

objFtpClient.setFileType(FTP.BINARY_FILE_TYPE);

objFtpClient.setFileTransferMode(FTP.BINARY_FILE_TYPE);

objFtpClient.enterLocalPassiveMode();

回答7:

For Me only ftp.setFileType(FTP.BINARY_FILE_TYPE, FTP.BINARY_FILE_TYPE) worked, while when I was using ftp.setFileTransferMode(FTP.BINARY_FILE_TYPE) File was getting corrupt.

回答8:

This looks like a bug in the Commons NET library, which affected version 3.0. Try a newer version (3.0.1), which fixed the bug.