Research And Design On Component Assembly Based On Active Services

Active services is a kind of brand-new and user-oriented Web services customization. It can adapt to user's service demand automatically and also can discover , customize and run the component program on the Internet, which could meet the user's need .The development of component technology provides the basis of implementing active services. The heterogeneous component description information turns into universal component description language through the corresponding mapping algorithm, which makes it possible to achieve transferring among the heterogeneous components.As the implementation mechanism of active services, program mining is based on component technology. The basic idea is to analyze user's demand, retrieve the components from the component library which can be assembled the program to meet the user's demand.Component assembly is the key to program mining. According to the assembly structure, the loosing components are assembled into an organic system by adding glue codes, then the system is compiled and implemented into user's running platform. The concept of component assembly involves the description of software architecture, assembly mechanisms, components retrieval, assembly structure checking and compiling, etc.In the paper, it proposes the component assembly based on active services adopts the component assembly intelligent agent mechanism. Based on the characteristics of software components and structured methodology, the component assembly intelligent agent system can be divided into three parts. The first one is Parser, with the responsibility of resolving the script which described by XML documents; the second is Controller, it is in charge of data transferring, messages sending, components controlling and so on; the last one is Packer and it is responsible for establishing the relationships between the components and the running environment, calling the components by receiving the calling messages and returning the results. According to the relationships among the components, the Controller can be divided into four types by different functions, which are sequence, switch, while, flow. It can adjust the assembly through checking relevant Controller but not affecting the rest of the system so that it can improve the reliability, maintainability and the flexibility of the system.Next, the paper presents an example of component assembly to validate the feasibility and rationality of this component assembly intelligent agent system based on active services.