Empty file after upload with JAVA on my ftp server

问题:

I am facing some problem while trying to upload a file on my ftp server with java. here is my code function :

public static void upload_files(String un, String pw, String ip, String f){
  try
    {
        FTPClient client = new FTPClient();
        client.connect(ip);
        client.login(un,pw);
        InputStream is = new FileInputStream(f);
        client.storeFile("test2",is);
        is.close();

    } catch(Exception e) {
        e.printStackTrace();
    }
    }

"f" is the path of the file I want to upload (ie "C:\myfile"). No error during the compilation, one file is well sent to the server, but sadly empty (0 byte).

I also noticed that it takes quite long for a simple upload of some text (around 40s) even thought I got a really good ISP.

I thank in advance all people who will help me.

Regards,

回答1:

I think it could be something to do with the mode of file transfer . Can you set the trandfer mode to Binary. Some times when you sent data in ASCII it goes corrupted . Refer to this https://superuser.com/questions/82726/how-to-set-binary-mode-by-default-when-ftping-to-a-remote-site

It tells how to set binary mode in FTP Command client. You will have a similar provision in FTPClient class also.

Just found I think similar question is answered here FTPClient - Java, upload file

回答2:

It seems like the problem has to do with the implementation of the FTPClient. Are you sure that the class works like that?

Try uploading to a different server or using a different class to find the reason for the failure.

Also: Are you sure that it is your responsibility to close the FileInputStream? I could imagine that the .storeFile(…) method will close it itself, when it is done.

回答3:

Add these lines before client.login ftpClient default protocol is full text only for other files you nead to specifie binnary mode

client.enterLocalPassiveMode()
client.setFileType(FTP.BINARY_FILE_TYPE, FTP.BINARY_FILE_TYPE);
client.setFileTransferMode(FTP.BINARY_FILE_TYPE);