If the data is received via HTTP/HTTPS, it would be the same process described previously in this thread by ArulchristhuRaj, except that step 1 would be different.
If the HTTP/S message has a contenttype recognized by IS as a flat file (i.e. listed in the tn.ff.contenttypes property), then the content will already be in a stream named ‘ffdata’, which is what wm.tn.doc.ff.routeFlatFile expects.
If the message has a different contenttype, you will need to get the content into an InputStream with a name of ‘ffdata’.
If you are writing Flow services, you can use the pub.io services to work with streams.
m.
#webMethods#B2B-Integration#Integration-Server-and-ESB