Research On Mechanism For Exception Handling Of Semantic Programming Language

SPL is a programming language that is based on processing semantic information and employes semantic Web services as primary structure of software system. Software systems developed by SPL, which was one of our previous research works, are always running in a dynamic, open network environment. This complex and changing context around software system cause exceptions frequently. Especially with the expansion of the scale of software and the improvement of the system complexity, exception occurrence rate and types increase significantly. Therefore, how to detect these exceptions and address them effectively when they occured, has become an urgent task for SPL language to solve.After Studying exception handling mechanisms of existed programming languages, this paper extends SPL to address exception, and then proposes exception mechanism both for description and handling, and discusses detection and unforseen exception handling methods. Besides, a designing and runtime supporting platform for SPL exception handling is designedFour shining aspects of our research work shown in this paper discuss as follows. Firstly, this paper introduces exception handling menchanism into SPL, which extend SPL to handle exceptions. Constructs, syntx and usage methods related to exception handling are defined, as well as a model for exception handling, on the basis of exploring the exception handling and operation mechanism in SPL. For better description of exception in SPL, this paper also classifies exceptions into several kinds and then builds ontology knowledge system for SPL’s exceptions. By exception handling mechanism, programmers can improve both reliability and robustness of Semantic Web services oriented software system. Secondly, an approach for detecting exceptions is also proposed in this paper, which provides support to identify exceptions at SPL’s runtime, based on event algebra and SWRL. In this approach, a semantic event model is built, and an anomaly detection algorithm for SPL also given based on this model. Thirdly, aiming at unforeseen exception duing the execution of SPL program, this paper proposes a semantic-based mechanism for address unforeseen exception which supports forward-recovery. Employing service semantic equivalence theory and Petri Net theory, this mechanism replaces unforeseen abnormal local control flow into the semantic equivalent ones, so that SPL can handle unforeseeable exceptions. Finally, based on our privious research work, a supporting platform for SPL exception handling is designed with Semantic Service Bus architecture driven by event and exception detection tools, as well as advanced graphic editing tool and execution engine of SPL.