Building the Core – Enterprise Business Flows - Applied SOA Patterns on the Oracle Platform - page 199

Agnostic Task Invocation
The only task associated with the designated provider is maintained in the Execution plan,
and this task is exactly what we want to execute. Thus, the extraction of this variable is
simple, and we pass it to Task Router (SCA Mediator). It is now the Mediator's job to sub-
stitute the actual endpoint URI with the variable from the task list.
This operation is similar for synchronous and asynchronous service brokers; only Mediat-
ors are different.
That's it! We can extract the XML task array from the metadata inventory; this array has
endpoint references, and we can loop through and invoke them synchronously or asyn-
chronously, get the result back, update an object's payload and its contexts, keep track of
the execution in a special placeholder of our XML container, and even react to errors with
predefined tasks in the same tasks array.
The mentioned endpoint reference term is part of the WS-Addressing vocabulary we
briefly discussed in Chapter 1 , SOA Ecosystem - Interconnected Principles, Patterns, and
Frameworks . Let's look at it a bit closer now. The endpoint reference is the XML con-
struct that allows us to select one of the available services in a WSDL. We can also define