As at now there does not seem to be a way to stream FTP payloads to the local file system, or stream local files to FTP servers in the JBI environment. This kind of functionality may or may not appear in the OpenESB project, perhaps in conjunctions with the FTP BC or the File BC or both. In the meantime, a Java CAPS 6 developer can use the JCA Adapters-based solution to stream payloads of arbitrary size between FTP servers and local file systems in either direction.
This Note walks through the implementation of a Batch FTP JCA solution, which is triggered by a JMS Message, and performs a streaming FTP transfer of an arbitrarily large payload between a remote FTP server and the local file system. This Note re-implements the inbound part of the “Java CAPS 5.1 and Java CAPS 6 – Streaming Large FTP Transfers” Note available at http://blogs.sun.com/javacapsfieldtech/entry/streaming_large_ftp_transfers_with.
It should be easy enough to re-implement the outbound part of that Note using the material in this Note.
The complete Note is available in 04JCAStreamingFTPIn.pdf.