[NET-91] commons.net.FTPClient hangs on disconnect or logout

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4

Environment

Operating System: All
Platform: PC

• Bugzilla Id: 17066
• Assignee: Unassigned
• Reporter: Joe
• Created: 14/Feb/03 07:37
• Updated: 20/Sep/07 05:24
• Resolved: 20/Sep/07 05:24

Description

By repetitively calling

try {

// connect and login to the FTP server
ftpc.connect(getPropertyFromEnv("FTP_SERVER"));

ftpc.login(getPropertyFromEnv("USERNAME"), getPropertyFromEnv
("PASSWORD")); //technically we may have to break this into 2 blocks see
examples

// After connection attempt, check the reply code to verify success.
reply = ftpc.getReplyCode();
response = ftpc.getReplyString();

if(!FTPReply.isPositiveCompletion(reply))

{ System.err.println("FTP server refused connection or login."); killFTP(ftpc); ftpc = null; }

} catch(IOException e)

{ System.err.println("Can't connect or login to server, reply = "+reply+ " response = " + response); killFTP(ftpc); ftpc = null; }

and then

if (ftpc.isConnected()) {
try

{ ftpc.logout(); }

catch (Exception e)

{ // do nothing System.out.println("Exception in ftpc.logout()"); }

try

{ ftpc.disconnect(); }

catch (Exception e)

{ // do nothing System.out.println("Exception in ftpc.disconnect()"); }

}

one of the two bottom calls hangs and I'm assuming that it's in an infinite
loop waiting for something that the server isn't sending. We try and hook to
a Linux FTP server, and Windows FTP server and 99.99 % of the time it works,
but every once in a while, it hangs and we have to kill the FTP daemon. After
doing that everything works again!!!

Issue Links

• is related to: NET-145 Deadlock in TelnetInputStream