BPELGEN: An Algorithm of Automatically Converting from Web Services Composition Plan to BPEL4WS

Service composition is a key issue in the pervasive computing systems of service orientation. Automatically converting web services composition plans into BPEL4WS is an essential step in SASO (Semantic and Automatic Service Orchestration system). In this paper, we employ DAG to represent web services composition plans, and propose an automatic conversion algorithm BPELGEN which automatically converts the DAG into BPEL4WS through dynamic code generation at runtime. There are three main characteristics of the algorithm: (1) automatically converting web services composition plan into BPEL4WS; (2) supporting nested flow process generation; (3) the BPEL4WS generated by the algorithm satisfying data dependency and execution dependency of the composition plan.