Background:
I have been using Commons/Net's FTPClient for about 9 months now. Its
awesome! I am utilizing the retrieveFile(String string, OutputStream
outputStream) method for retrieving files. I am retrieving zip files (avg
1MB in size) on a periodic (15min) basis and storing them on localhost
(Solaris 8) for further processing. These zip files are generated and
stored by another company on a remote FTP Server (Windows).
Here is my wrapper around the FTPClient's(ftpConn) retrieveFile():
public boolean retrieveFile(String fileName, OutputStream fileOutput) {
boolean fileRetrieved = false;
if (!ftpConn.isConnected()) {
this.reconnect();
}
if (ftpConn.isConnected()) {
try {
fileRetrieved = ftpConn.retrieveFile(fileName, fileOutput);
} catch (IOException ioe) {
log.warn("FTPUtil - retrieveFile(): ", ioe);
}
}
return fileRetrieved;
}
Problem:
Recently my process that is retrieving the zip file seems to hang at
'fileRetrieved = ftpConn.retrieveFile(fileName, fileOutput);'. If it
entered the 'this.reconnect()' I would see log messages stating entry, but I
don't so its not entering that method. I don't see a IOException being
throw and the method never returns. It isn't hanging on a regular basis
either, sometimes it takes 1 -2 days to occur. The most recent encounter
was 6 days before a hang was encountered. I see that the zip file is being
created locally from the outputStream, but it remains at 0K in size even
through the server file is 1MB.
I also performed the following after a hang has occured:
'netstat -a | grep remoteservername'
tcp 0 0 192.168.130.98:35717 remoteservername:ftp ESTABLISHED
Does anyone have any ideas?
Thanks,
Ethan
----
Ethan Knepp
Software Engineer
C-COR Incorporated
www.c-cor.net
