Study On Dynamic Information Integration Based On Mediator/Wrapper

With the rapid development of computer networks and the strong advance of information construction, now the amount of information available on-line is proliferating at a tremendous rate. However, all those information for many different applications is independently stored in a great variety of data sources and managed by different systems, and their contents, structures and quality are different in thousands ways. In order to utilize this information more effectively, there is a need to integrate information from multiple distributed, heterogeneous and autonomous sources, and make differences invisible and provide uniform and transparent access to the data for all users. In addition, it is necessary to preserve data integrity and consistency over different systems. Thus, how to resolve those differences efficiently is a severe challenge in the domain about application and research of information integration.Based on summarizing series of important research works on information integration and combining J2EE platform and Mobile Agent and RDF, this dissertation has presented a dynamic information integration system based on mediator/wrapper——BMWDII. During the process of establishing BMWDII, the paper analyzed common data model and schema integration detailedly and has designed a particular structure of integration based on banding J2EE and Mobile Agent together. In addition, mediator and wrapper were designed in detail. At the same time, the dissertation researched global query optimization of integration system. The primary tasks of the paper are as follows:1) Introduced key technology used in BMWDII system, which were mobile agent and RDF technology. In addition, analyzed what advantage mobile agent and RDF can bring to integration system.2) Has presented the idea of Unit Data, and has built common data model based on RDF according to the feature that Unit Data can match RDF technology seamlessly, and furthermore, analyzed how to map several main data models used at present into RCDM. At the same time, we studied on schema integration according to the common data model designed in the paper.3) We designed mediator and wrapper by mobile agent and RDF detailedly. In addition, we designed Change Agent to adapt to dynamic changing of data structure in different datasource in particular.