Applying Metadata And XML To Construct Distributed Data Shared Platform

Infomatization is one of the most important method to drive the society development. Today technology that is characterized by computer and communication makes the utilization of information resource become a -n efficient, professional, various way with the character data shared. Information becomes the core location of improving productivity and the strategic resource of the nation. In the course of social infomatization, various information increase at an explosive speed. However, most of information is isolated, which can only serve for their own domain. As a result, information islands come into being. People are not able to produce data badly needed independently because of the vast information island and the expensive cost of information. They have to get the data and resource by the data shared technology. Therefore, how to share data is one of the problems that is badly needed today with the development of information technology. How to share more various data resource in wider domain is of great significance for the strategy of infomatization, which can provide a quick query and mutual platform to save the current application system and resource reasonably and reduce the cost of system integration for a second time.Some data shared technology such as file shared, database shared, metadata shared technology are used today. They alleviate the pressure that information can not be shared effectively to some extent. But the type of shared data is single without the ability of sharing more types of data.The system described in this paper uses the technology of metadata and XML to implement the function of data shared, which assure the original character of resource without any change in that metadata is good at describing the non-structural data and XML is extensible dynamically to describe structural data. The data shared platform that is based on metadata and XML, use comparative mature and advanced technology such as J2EE and Web Services to implement the connection and access to isomerous data source, which satisfy the request of query from different types of client. This system use XML as the media for the data exchange in data shared platform, and improve the extensibility and the ability of transplantable of system, in which the query condition from clients and the query results form server are conducted by XML. The authentication based on JAAS together with authorization and audit function provided by J2EE application server assure the security control for system.