Web Services Invocation Framework

In real-world scenarios, a business process will often have to invoke operations on services that have not been implemented as web services. Enterprises usually have several applications and systems that incorporate valuable business logic. Not all this logic has been exposed as web services. Although exposing functionality as web services is quite straightforward, there are several reasons why we might prefer not using web services and instead access resources directly. Converting existing resources to web services is time consuming and requires additional resources on the server. Web services have to be secured adequately as they are accessible from everywhere, even outside the firewall. Web services usually also perform slower than native resources and do not provide automatic propagation of transaction contexts.

In this section, we will overview the Web Services Invocation Framework (WSIF). It allows connectivity of BPEL processes with resources other...