Exposing and implementing an asynchronous interface requires something extra compared to synchronous services. Invoking these interfaces and preparing for the callback response is even more of a challenge, as we will see in this section when we invoke an asynchronous operation from both a BPEL component as well as a Service Bus project.
The service we will implement using BPEL is called LessThoughtfulGreeterService - it publishes a synchronous interface on top of the asynchronous ThoughtfulGreeterService
We will next implement the same thing using Service Bus – and that turns out to be a little bit more complex:
Create an Asynchronous JAX-WS Web Service and call it from Oracle BPEL 11g – Bob Webster’s Blog
Oracle Service Bus: thread blocking evidences, transport level – ATX Systems by Fabio Mazanatti
The starting point sources are in the folder AsynchronousServiceBusApplication-step1 (for the Service Bus application). The end result for this section is in the AsynchronousServiceBusApplication-step2 folder for Service Bus and in LessThoughtfulGreeterService for the SOA Composite with BPEL.