In certain error/failure circumstances ftpClient.listFiles(param) returns an empty list instead of null or an exception -----------------------------------------------------------------------------------------------------------------------
Key: NET-427 URL: https://issues.apache.org/jira/browse/NET-427 Project: Commons Net Issue Type: Bug Components: FTP Affects Versions: 3.0.1 Environment: SunOS 5.10 Generic_144489-06 Reporter: Mario Zannone Priority: Minor According to the API docs ftpClient.listFiles(String) should return null or an exception on error conditions or failure: The convention for all the FTP command methods in FTPClient is such that they either return a boolean value or some other value. The boolean methods return true on a successful completion reply from the FTP server and false on a reply resulting in an error condition or failure. The methods returning a value other than boolean return a value containing the higher level data produced by the FTP command, or null if a reply resulted in an error condition or failure. ( http://commons.apache.org/net/apidocs/org/apache/commons/net/ftp/FTPClient.html ) However in certain error/failure circumstances listFiles(param) returns an empty list instead of null. Note that an empty list is a correct response when param does not match any file. We were able to bypass the problem checking the ftp reply with getReplyCode(). However, this listFiles behaviour is unexpected and should at least be documented. The error is not systematic and not easy to diagnose or replicate. We were able to reproduce it using cron to run the attached program every minute on a slow and unreliable connection; in 24h the error did show only a couple of times. Attachments: test program and excerpt from the test log. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira