When a service provider application that has been deployed using the CICS® Web services assistant is invoked, CICS links to it with a COMMAREA or a channel.
You specify which sort of interface is used when you run JCL procedure DFHWS2LS or DFHLS2WS with the PGMINT parameter. If you specify a channel, you can name the container in the CONTID parameter.
When
you code API commands to work with the containers, you do not need to specify
the CHANNEL option, because all the containers are associated
with the current channel (the channel that was passed to the program). If
you need to know the name of the channel, use the EXEC CICS ASSIGN
CHANNEL command.
When your program has processed the request, it must use the same mechanism to return the response: if the request was received in a COMMAREA, then the response must be returned in the COMMAREA; if the request was received in a container, the response must be returned in the same container.
If an error is encountered when the application program is issuing
a response message, CICS rolls back all of the changes unless the application
has performed a syncpoint.
If the Web service provided by your program is not designed to return a response, CICS will ignore anything in the COMMAREA or container when the program returns.