| description |
Message exchange patterns provide means to define the message flow
of a service and how these messages are related in an abstract and
reusable manner. They are an integral part of WSDL 2.0 and allow
defining operations that have a message exchange beyond
requestresponse. They reduce the impedance mismatch between
imperative programming and message orientation while emphasizing the
message orientated nature of Web Services. Whereas BPEL defines a
flow between Web Service operations, BPELlight is an appropriate
candidate to define the flow within operations since it abstracts
from WSDL. In this paper we extended BPELlight to facilitate
capturing complex multi-lateral message exchanges. We refine the
partner model and relax the definition of a conversation to enable
modelling conversations that involve different partner types. We
also extend the language with a first-class construct that enables
storing, querying and thus distinguishing addressing information
related to multiple partner instances. This way we enable modelling
message exchange patterns that capture business logic in a reusable
manner on an abstract level like for instance a request for bid
scenario or a business transaction for purchase.
|