GPRS connection

Question

I'm trying to use edtjFTP over a GPRS wireless connection. This is a cell phone based standard that gives about 40kb/s bandwidth.

However, i am finding errors appearing that were not there on my fixed connection tests. Using the standard demo within the package the console reports

INFO [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:23:31.381 : edtFTPj version: 1.5.2
INFO [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:23:31.391 : edtFTPj build timestamp: 20-Sep-2005 10:43:01 BST
INFO [Demo] 24 Feb 2006 23:23:39.203 : Connecting
DEBUG [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:23:39.213 : Connecting to *************************
ERROR [Demo] 24 Feb 2006 23:23:42.607 : Demo failed : Connection reset
java.net.SocketException: Connection reset
   at java.net.SocketInputStream.read(SocketInputStream.java:168)
   at sun.nio.cs.StreamDecoder$CharsetSD.readBytes(StreamDecoder.java:408)
   at sun.nio.cs.StreamDecoder$CharsetSD.implRead(StreamDecoder.java:450)
   at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:182)
   at java.io.InputStreamReader.read(InputStreamReader.java:167)
   at java.io.BufferedReader.fill(BufferedReader.java:136)
   at java.io.BufferedReader.readLine(BufferedReader.java:299)
   at java.io.BufferedReader.readLine(BufferedReader.java:362)
   at com.enterprisedt.net.ftp.FTPControlSocket.readReply(FTPControlSocket.java:681)
   at com.enterprisedt.net.ftp.FTPControlSocket.validateConnection(FTPControlSocket.java:281)
   at com.enterprisedt.net.ftp.FTPControlSocket.<init>(FTPControlSocket.java:261)
   at com.enterprisedt.net.ftp.FTPControlSocket.<init>(FTPControlSocket.java:234)
   at com.enterprisedt.net.ftp.FTPClient.connect(FTPClient.java:604)
   at Demo.main(Demo.java:104)

or more recently

INFO [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:55:35.27 : edtFTPj version: 1.5.2
INFO [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:55:35.27 : edtFTPj build timestamp: 20-Sep-2005 10:43:01 BST
INFO [Demo] 24 Feb 2006 23:55:36.68 : Connecting
DEBUG [com.enterprisedt.net.ftp.FTPClient] 24 Feb 2006 23:55:36.68 : Connecting to **********************
ERROR [Demo] 24 Feb 2006 23:55:37.540 : Demo failed : Unexpected null reply received
java.io.IOException: Unexpected null reply received
   at com.enterprisedt.net.ftp.FTPControlSocket.readReply(FTPControlSocket.java:686)
   at com.enterprisedt.net.ftp.FTPControlSocket.validateConnection(FTPControlSocket.java:281)
   at com.enterprisedt.net.ftp.FTPControlSocket.<init>(FTPControlSocket.java:261)
   at com.enterprisedt.net.ftp.FTPControlSocket.<init>(FTPControlSocket.java:234)
   at com.enterprisedt.net.ftp.FTPClient.connect(FTPClient.java:604)
   at Demo.main(Demo.java:104)

I can't tell if this is network specific or something to do with edtjFTP. Obviously the network is returning an odd command. Is there anyway i can access it and figure out whats wrong.

Thanks

Answer 1

Is there any way you can generate a log file? (see the dev guide for how)

Answer 2

i dont understand what would be different by supplying a log file, since all i have copied there is the system out which would be dumped to the log file in any case.

I have set the logging level to debug and there is no difference really

Using the demo code solely, adding

Logger.addAppender(new FileAppender(log));

does not compile anyway.

I'm beginning to suspect this is a network problem. i have now encountered the same error on two networks. One was a university network and the other a GPRS. However each time its the server that sends a null reply, indicating it might not be? Or perhaps partial ports are blocked?

Answer 3

Try a commandline FTP client if possible.