Research On Web Service Based E-Government Architecture And Key Technologies

Electronic government (e-government) is an effective means to improve office efficiency, service quality and information sharing. With the development of information construction in Chinese government systems, quite a lot of information systems have been developed according to different needs of different departments. However, these systems are respectively independent, which are difficult to coordinate with each other, and have become a number of "isolated information islands", which significantly hinder further development of e-government. To achieve "one stop" service platform of e-government, the key problems are to address the application integration and data exchange across multiple departments. This dissertation explores how to build up an e-government architecture, which can drive service-oriented and multi-level systems, and to integrate the decentralized, loosely coupled subsystems into a unified large-scale distributed computer application system. The main research contents are as follows.(1) Focusing on the key problem that the integration solution of tight coupling and hard coding cannot meet the needs of mutual action and silent functionality update of current e-government systems, by systematic analysis on traditional applications integration model for e-government systems, improving the technique of Web service, and encircling the core technique of e-government application integration, this dissertation puts forward a new architecture of Web service with the characteristics of high availability and silent functionalities update. Through theoretical analysis and practical application, the proposed new architecture shows significant advantages on feasibility and flexibility in e-government architecture.(2) Focusing on the problem that existing systems in e-government architecture among different governments cannot meet the needs of timely accessing and data sharing, this dissertation systematically analyzes the shortcomings in distributed architecture, event-driven fast accuracy response and so on in traditional e-government architecture, especially in the application architecture and software architecture in e-government systems. A shared service architecture based on Web service is proposed, which can meet the requirements of accessing speed and data sharing in e-government systems. Furthermore, it realizes the central service platform, sharing application platform and sharing business service platform. The results of theoretical analysis and practical application indicate that sharing service architecture based on Web service has great significance for promoting e-government integration of crossing applications and crossing fields.(3) In a complicated e-government system, different government departments have already established and will continuously create a large number of heterogeneous databases. Just by using data replication and synchronization technology as the low level infrastructure to maintain the huge systems is very difficult to get satisfactory result. Systematic analysis and research shows that a unified data center constructed with Web service technique and XML schema can give a good solution to problems with business logic method invocation and transparent data exchange, and thus achieve better data sharing. Meanwhile, it can not only assure the data uniformity between different databases by using a data center constructed with Web services, but also make it easy to integrate old systems and add new systems by introducing the concepts of finding and searching of Web services. Theoretical analysis and practical applications indicate that a data center constructed with Web services has great advantages on data sharing, data uniformity and other aspects in e-government architecture.(4) Security issues in Web service systems involve the issues of reliability, confidence, and lack of clear and enough information. In order to improve the security of heterogeneous independent Web service environments, a novel dependability model named WDSV (Web service Dependability by using System-level Virtualization) of Web services is proposed by using virtualization techniques. The main contributions can be summarized as follows:1) A new general formal WDSV model with good scalability of Web service systems is put forward, and systematic analysis on how WDSV model enhancing the system dependability is given;2) The proposed WDSV construction is given with the definition of dependability in Web service systems and a series of quantitative indicators to evaluate the dependability;3) It is proved that WDSV model can realize better reliability and effectively enhance the security of Web service systems. The WDSV model has significant value for related research on Web service system security.(5) Focusing on the requirements of high expansibility, high availability and high disaster tolerance and so on in Web service architecture, according to the core architecture design methodology of "real platform, virtual applications" and "unity of command and control network", the dissertation systematically analyzes the application infrastructure layer, the service infrastructure layer and the uniform open platform, studies particularly the key contents of the general data architecture, database architecture and database server configuration and so on, and puts forward an e-government scheduling architecture with Web services based on SOA platform. The planning and construction of the e-government scheduling system with Web services involves seven layers, which are the accessing layer, application server layer, Ethernet layer, database server layer, fiber-optic network layer, storage layer, and operation and maintenance management layer. Further practical analysis of the e-government scheduling system with Web service has been accomplished from six aspects, which are the SOA platform architecture, database architecture, server architecture, storage architecture, network architecture and security architecture. Theoretical analysis and practical applications show that the e-government scheduling system with Web services can achieve high scalability, high availability, high disaster recovery, and high performance.