Towards Aspect Oriented Web Service Composition with UML

The greater value is derived from assembling web services into more powerful composite web services than in accessing a single web service. Now some specifications related to composition have been proposed, such as BPEL. However, current composite specifications suffer some weaknesses: (1) The current composite specifications cannot support dynamic adaptation of composition; (2) The current composite specifications also cannot explicitly modularize concerns that cut across the composition boundaries; (3) The compositions described by these specifications, lacking a standardized visual representation, are not easy to be read for human engineers. Although some approaches have been proposed to address these problems, no complete solution has been found yet. This paper presents a modeling approach for aspect oriented web service composition with UML. We first use UML to model the basic Web service composition for addressing (3). Then we design the aspects for "pluggable" behaviors with UML to address the problem (1) and (2) and bind the aspects into the basic model to get the complete model.