Java Development

[dx22]

Is the File Transfer Protocol (FTP) supported and can you programmatically upload a file to a server through FTP?

Any links with code and information will be appreciated.

[simon_hain]

there is no API for that built in, but you can check out some j2me FTP clients i guess.

[dx22]

OK thanks. Do you know any more popular j2me libraries which I could try to port?

[peter_strange]

One issue with FTP access on the BB can be file size.  BIS-B and BES connections go through RIM's proxy and it will kill a connection after a certain number of bytes are sent during a connection.  FTP is not restartable too, which makes this a little difficult....

Anyway, I wrote this last year and meant to publish it but never got round to it because I thought the approach was flawed.  If you find it useful or find any bugs let us know, perhaps you can publish a correction.....

Free to use code.  Don't ask me any questions and expect instant answers, I have not looked at this code in a year....

[dx22]

Nice! Thanks very much. I will take time and test it during the next few days.

It worries me a little what you said about file size limitations. Is this only applicable for BIB-B and BES connections or it applies to all transports?

And do you have a rough idea how much can you transfer before the connection is killed - 1MB, 10MB?

Thanks again

[peter_strange]

The size transferred depends on the settings in the proxy.  Used to be quite small, but now I think the default BES setting is in the 1MB region.  As noted, Carrier, WiFi and WAP do not have this restriction.  The killer for me was the lack of restart in FTP. 

[dx22]

Ok its good to know that at least through wifi you can transfer larger files.

By lack of restart you mean you cannot restart the file upload and if for some reason the upload fails you might end up with corrupted file on the server? Or I misunderstood this?

[simon_hain]

resume is a ftp feature as far as i know. not all servers implement it correctly though.

see http://www.ietf.org/rfc/rfc0959.txt

[peter_strange]

Can you point me at a spec Simon?  If I can implement something standard it makes the project worth doing....

[simon_hain]

http://cr.yp.to/ftp/retr.html maybe?