From: Rohit Khare (Rohit@KnowNow.com)
Date: Thu Aug 03 2000 - 18:45:47 PDT
If the RPC is carried over SMTP, then it goes to a mailbox and sits
there waiting to be acted upon. We provide a POP3 to HTTP to SMTP
bridge to receive these mail messages, post the content to an HTTP
SOAP endpoint, get the result and forward the result by mail (SMTP)
to the original sender. The receiving side will poll the POP3 server,
receive the message, extract the content, unmarshall and return the
Response to the original caller.
RPC over SMTP
To do RPC over SMTP in XML-SOAP a certain amount of email
infrastructure needs to be available. Namely, you need an SMTP
server, a POP3 server and an email address that you can use to be the
equivalent of the server-side HTTP router. That is, all SOAP RPC
calls are sent to a specific address which then processes the request
somehow and send the result to the sender. To avoid duplicating the
server-side infrastructure, we have implemented the SMTP server-side
as a bridge that receives mail sent to the SOAP router email address
via POP3, posts the SOAP envelope to an existing HTTP SOAP
infrastructure and sends the response back to the sender of the email
request via SMTP.
On the client side, the application sends the SOAP request via SMTP
to the SOAP router email address indicating the address that the
response should be sent to. Then, it starts polling a POP3 server to
see whether the response has arrived. When it does, the envelope is
parsed and the respose is extracted. We are using a for the POP3
stuff and that bean does not support selective downloading of email.
As a result, the current implementation relies on the "next message"
arriving to the client's reply address to be the message containing
the response to the request. The implication is that current
implementation does not allow you to make multiple RPC calls using
the same reply address at the same time.
NOTE: We strongly recommend against using your own email address for
testing RPC over SMTP. There are many free POP3 email providers on
the Web (such as www.mailandnews.com, for example) if you are unable
to set up multiple POP3 accounts yourself.
This archive was generated by hypermail 2b29 : Fri Aug 04 2000 - 23:30:43 PDT