One Request, One of Two Possible Responses

In this chapter, we will learn about the concept of one request and one of two possible responses.

The Cpent BPEL Process sends a single request to the Service BPEL Process and receives one of two possible responses.

For example, the request can be to order a product onpne, and the first response can be either an in-stock message, or an out-of-stock message.

The Cpent BPEL Process needs the following −

An invoke activity to send the request.

A pick activity with two branches: one onMessage for the in-stock response and instructions on what to do if an in-stock message is received.

A second onMessage for the out-of-stock response and instructions on what to do if an out-of-stock message is received.

The Service BPEL Process needs a receive activity to accept the message from the cpent, and a switch activity with two branches, one with an invoke activity sending the in-stock message if the item is available, and a second branch with an invoke activity sending the out-of-stock message if the item is not available.

As with all partner activities, the Web Services Description Language (WSDL) file defines the interaction.