how to delete file from ftp server using java?

问题:

How can I delete a file from an ftp server using a java program? I am successfully able to upload files on the ftp using the following code:

public static void main(String[] args) throws IOException {
    // TODO Auto-generated method stub
    String s = "ftp://username:password@ftpclient:21/text.txt;type=i";
    URL u = new URL(s);
    URLConnection uc = u.openConnection();
    BufferedOutputStream bos = new BufferedOutputStream(uc.getOutputStream());
    bos.write(67);
    bos.close();
    System.out.println("Done");
}

But how do i delete files from this ftp server? Any help will be greatly appreciated......... Thanks in advance

回答1:

You can use Apache FTPClient to do this and all other commands on FTP. Use it something like this:

...
FTPClient client = new FTPClient();
client.connect(host, port);
client.login(loginname, password);
client.deleteFile(fileNameOnServer);
client.disconnect();
...

回答2:

Check out Apache commons-net. It has an FTP client (among other stuff).

回答3:

The FTP command to remove a file is RMD, I think you could use:

String s = "ftp://username:password@ftpclient:21/text.txt;type=i";
URL u = new URL(s);
URLConnection uc = u.openConnection();
PrintStream ps = new PrintStream((uc.getOutputStream()));
ps.println("RMD " + <myFile>.getPath());
ps.close();

回答4:

Java's URL and URLConnection do not have support for deletion of resources. (I'm even surprised that upload works).

So you'll either have to use an FTP client library (like FTPClient from Apache Commons Net), or have to implement the necessary parts of the client side of the FTP protocol yourself.