Commons.net FTP Loop call Listfiles () return value is only normal for the first time, and later returns an empty Ftpfile array

Use the Retrievefilestream (filename) method to read a heap of file names generated by a particular rule, looping through file names.

Use the Listfiles (FileName) method to determine whether the file exists before reading it.

In the result loop, the first time the file exists, each subsequent loop is judged to be nonexistent.

I checked the Internet. Retrievefilestream (fileName) method returns a InputStream after using InputStream

You need to close the IS and call the Completependingcommand () method after closing. To make sure the flow is done!

Problem solving. Record it.

Commons.net FTP Loop call Listfiles () return value is only normal for the first time, and later returns an empty Ftpfile array