Introduction

In the SOA architecture, BPEL plays the role of the orchestration technology. Its main task is to efficiently coordinate the interaction between web services in the business processes. With the vendor extensions, it is also possible to orchestrate EJB, Java, Spring, REST, and the other compositions.

The design of the BPEL processes requires the orchestration of many web services, each with its own interface and a way of interaction with the outer environment. There will be rare cases when web services along with a business process are in our domain. Web services, in this case, are distinct entities, and so we need to adapt our business process to the interface of the calling web service. In such a scenario, we often encounter the incompatibilities of the web service interfaces. Consequently, the job of BPEL is also the translation of some web service outcome to become the request of another web service. We have already seen that some basic transformations can be done with the...