The Research For Dynamic Web Services Composition Based On BPEL

Web Services provide the uniform interfaces and invocation patterns for services on networks. And the purpose of service composition, is reusing existing services to generate new services in SOA, which shows a bright future of large applicability and great research value. Currently, most of academic researches of dynamic service compositions are focus on automatic composition methodologies and designs of composition frameworks, and most industrial developments are focus on the infrastructural supports and expressions of services compositions. The joint of those two aspects, however, which is dynamic Web Services composition, hasn't caught those researchers' and developers' eyes.Firstly, we briefly introduce the conception of Web Services, and analyze the significance of Web Services and compositions. Then we review the specification of BPEL 1.1 and its infrastructure. The BPEL, which is based on the methodology of business process orchestration and using other Web Services' specifications, provides a way to the realization of dynamic Web Services composition.This paper also unscrambles those key points of BPEL specification. BPEL has a great number of structures and aspects that need special attention to handle them for more appropriate designation. We also summarize several design principles which can be used in BPEL design, to make the description more clear.Finally we design the FutureTrip platform for trip planning, and the sub-platform of services composition is based on a BPEL engine. The platform satisfies the requirements from practice and design principles mentioned above, and shows the capabilities of dynamical invocation of services and dynamical deployment of endpoints, which mean the dynamic service composition.