By starting the processor, an FTP server is started that listens for incoming connections on the specified port. Each file copied to this FTP server gets converted into a FlowFile and transferred to the next processor via the ListenFTP processor's 'success' relationship.
Before starting the processor, the following properties can be set:
After starting the processor and connecting to the FTP server, an empty root directory is visible in the client application.
Folders can be created in and deleted from the root directory and any of its subdirectories.
Files can be uploaded to any directory. Uploaded files do not show in the content list of directories, since
files are not actually stored on this FTP server, but converted into FlowFiles and transferred to the next processor via the
'success' relationship. It is not possible to download or delete files like on a regular FTP server.
All the folders (including the root directory) are virtual directories, meaning that they only exist in memory and do not get created in the file system of the host machine. Also, these directories are not persisted: by restarting the processor all the directories (except for the root directory) get removed. Uploaded files do not get removed by restarting the processor, since they are not stored on the FTP server, but transferred to the next processor as FlowFiles.
When a file named for example text01.txt is uploaded to the target folder /MyDirectory/MySubdirectory, a FlowFile gets created. The content of the FlowFile is the same as the content of text01.txt, the 'filename' attribute of the FlowFile contains the name of the original file (text01.txt) and the 'path' attribute of the flowfile contains the path where the file was uploaded (/MyDirectory/MySubdirectory/).
The list of the FTP commands that are supported by the FTP server is available by starting the processor and issuing the 'HELP' command to the server from an FTP client application.