Conclusion

In this chapter, you have become familiar with the basic concepts of web service composition with BPEL. BPEL is an XML-based language for business process definition. Each process has a set of activities and interacts with partner web services. The BPEL process is also a web service.

With BPEL we can define executable and abstract business processes. In this chapter we have focused on executable processes. They exactly define the activities of the processes and can be executed on a BPEL-compliant server. We have overviewed the basic concepts of BPEL, described how to invoke web services synchronously and asynchronously, and discussed the role of WSDL. BPEL processes can be synchronous or asynchronous and we have overviewed both options. Web services with which a BPEL process interacts are called partner services. Therefore we have explained the concepts of partner link types and partner links.

We have overviewed the most important activities for invocation of operations, receiving...