Research and Design of Heterogeneous Data Exchange System in E-Government Based on XML

Transcription

1 Research and Design of Heterogeneous Data Exchange System in E-Government Based on XML Huaiwen He, Yi Zheng, and Yihong Yang School of Computer, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan, Guangdong Abstract. To solve the information island problem in e-government system, this paper presents a heterogeneous data exchange model based on XML standard and Web Service transport technology. Using SOAP encapsulation mechanism and XML encryption to provide data transport security from data exchange center system to each bureau branch OA system. A dynamic configurable adaptor was implemented to translate between data center system and each bureau branch OA system. This model elevated data exchange level from simple data sharing to directly government business exchange and it has been applied and tested in practice. Keywords: e-government, heterogeneous data exchange, XML, Information Island. 1 Introduction In the process of e-government construction over past ten years, some achievements have been obtained. Accompany with the rapid development of e-government, there have been many problems, in which the most serious problem is that it is extreme difficult in data sharing and exchanging among government agencies because of the differences of applications, construction, system structure and data resources in original departments. For the reason of scattered data resources, many information islands were formed and information can not effectively share on online e-government system, especially in the process of business needed parallel approval among various departments, which business data flow between various departments. Therefore, the data exchange among departments has become the first problem to be solved for parallel approval. For these reasons, a centralized heterogeneous exchange model base on XML, Web Service technology was proposed in this paper. By using XML data exchange standards and data conversion adapter, data exchange between client and central system can be implemented which has great practical significance and is easy applied in China. 2 The Design of Heterogeneous Data Exchange System Now many cities have built one-stop parallel approval system to improve government office efficiency. The one-stop parallel approval system uses centralize exchange way D. Jin and S. Lin (Eds.): Advances in CSIE, Vol. 2, AISC 169, pp springerlink.com Springer-Verlag Berlin Heidelberg 2012

2 362 H. He, Y. Zheng, and Y. Yang which includes a data exchange center as middleware of data exchange. The main function of data exchange center is managing data which flow between different departments, and ensure data uniqueness, data availability and data submit in workflow process, which application model is shown as figure 1: Fig. 1. Application model of data exchange system By data exchange center in one-stop parallel approval system, each department can simply share data and exchange file. But because of fundamental difference of content of exchange data, and without uniform standard in each department OA system, therefore, in order to ensure the universal and independence of data exchange center in one-stop parallel approval system, it need to define a data exchange standard based on XML[1]. Therefore, when each department exchanges data with data exchange center, it need to convert its own business data format to data exchange center predefined data format, then uses data exchange service provided by data exchange center. Data exchange system as a data center system matching system, provides service to each department which need exchange data, and integrate it into workflow system in one-stop system, can be seem as relatively independent system, which forms a loose coupling relation with data exchanging center. To implementing business data exchange, we design a centralized exchange model and its structure is shown as figure 2:

3 Research and Design of Heterogeneous Data Exchange System 363 Fig. 2. Architecture of data exchange system The data exchange system consists of the following four modules: (1) Data exchange center system. Be responsible for transforming data flow and converting data format between different departments. Through the center adapter module, data exchange center system obtains business data according to the configuration file from extranet. Then a new business approval will generate which is analyzed and managed by process tracking module and process handling module in data exchange center and the new approval workflow will be corresponds to the proper department. (2) Network transmission module. Be Implemented by Web Service technology. This module uses soap s to encapsulate and transport XML business data and binary file upload and download, which is independent with concrete physical network condition and firewall[2]. (3) Security module. Use the XML SOAP encryption and XML electronic signature technology based on PKI technology to replace traditional SSL encryption.

4 364 H. He, Y. Zheng, and Y. Yang (4) Client converting adapter. Be responsible for exchanging data and docking between each department OA system and data exchange center. The client adapter access files from data exchange center and upload internal approval results by invoking the Web Service[3]. 3 The Design of Client Converting Adapter Acting as an interface between data exchange center and department OA system, application adapter system mainly implements application connection, data conversion, data mapping, application interface call and other functions. In another word it is selection, delivery and management of data[4]. Application adapter consist of five modules which include XML analyzer, data import, data export, timing driver and file transfer, which structure is shown as figure 3: Fig. 3. Functional structure of application adapter Details of each module are as following: (1) XML analyzer: mainly be used to analyze the structure of configuration file, so that the data exchange center system can obtain the business system interface of specific department. (2) Data import: be use to obtain interfaces of its own department business systems by analyzing XML configuration file, and mapping data from other departments, making data effective, then write data into its own background database systems in specific sectors, and store attachment in specified location, at last generate a new business process in its own business systems. (3) Data Export: be use to obtain interfaces of its own department business systems by analyzing XML configuration file and periodically check its own background database system to obtain the state of pending processes. After gaining approval

5 Research and Design of Heterogeneous Data Exchange System 365 state, the approval data finished will convert into the format of data exchange system and be written it into a specific directory on the server. (4) File transfer: by using specific network protocol to transfer files with other departmental and periodically obtain data from other departments, Meanwhile, this module specific directory use for uploading files to servers of other department. This module mainly provides an interface, the actual model file transfer services will be provided by Web services transport layer[5][6]. (5) Timing driver: work like an agent, which periodically drive data export module check the status of pending process and periodically drive file transfer module go to the business system which had sent agent requests, and query the approval results[7]. In the subsystems of different department, XML is used when data interfaces were offered to external, and a unified set of XML data specification was followed, which resolved the problem of inconsistent data structure and data dictionary in multi-level networking[8].figure 4 was the standard of XML packet received by city council, including process ID, approving opinions and so on[9]. Example: municipality, virescence cutting, pruning,migration seedlings application, receiving data <?xml version="1.0" encoding="gb2312"?> <XDE xmlns=" <flowid>1672</flowid> <instanceid>5457</instanceid> <stepid>3</stepid> <practicer>szj:0</practicer> <docfile></docfile> <exfile></exfile> <field><name>jldyj</name><value>1</value></field> <field><name>ylkps</name><value>approve</value></field> <field><name>jldps</name><value>approve</value></field> <field><name>ylkyj</name><value>1</value></field> </XDE> Fig. 4. Receiving XML data standard by municipality 4 Application of Data Exchange Model Heterogeneous Data Exchange System in E-Government Based On XML was well applied and tested in the one-stop parallel approval E-government system of Zhaoqing City, Guangdong province. Multiple administration department data exchange has been completed, for example data exchange of urban and rural planning bureau(c/s architecture, SQL Server Database), City council (J2EE architecture, Oracle database), Health bureau (Lotus Domino). This system realized the seamless heterogeneous data exchange among government agencies and parallel approval data center.

6 366 H. He, Y. Zheng, and Y. Yang 5 Conclusions This paper is focus on current Information Island background and difficulty of heterogeneous data exchange among government agencies in e-government system. A centralized heterogeneous data exchange model based on XML and Web Service technology was designed and realization. XML was used as standard of data exchange and Web Service technology was used in transmission, which resolved the problems of data mapping and data transfer among heterogeneous database. An adapter subsystem was designed to achieve the government data exchange by the conversion of XML documents. Finally, the joint work of scattered government agencies was realized. References 1. Liu, Y., Yao, S.: Relational storage of XML and data exchange between XML and RDBMS. Computer Engineering and Design 25, (2004) 2. Widener, P., Eisenhauer, G., Schwan, K.: Open metadata formats: efficient XML-based communication for high performance computing. In: Proceedings of 10th IEEE International Symposium on High Performance Distributed Computing, pp (August 2001) 3. Sakamuri, B.C., Madria, S.K., Passi, K., Chaudhry, E., Mohania, M., Bhowmick, S.S.: AXIS: A XML Schema Integration System. In: Song, I.-Y., Liddle, S.W., Ling, T.-W., Scheuermann, P. (eds.) ER LNCS, vol. 2813, pp Springer, Heidelberg (2003) 4. Seligman, L., Rosenthal, A.: XML s Impact on DataBases and Data Sharing. IEEE Computer (37), (2002) 5. Greunz, M., Schopp, B., Haes, J.: Integrating e-government Infrastrcutures through Secure XML Document Containers. In: Proceeding of the 34th Hawaii International Conference on System Sciences 2001, pp (2001) 6. Palavra, D., Lisnjic, D.: Web services as standard of connecting heterogeneous information systems. In: 26th International Conference on Information Technology Interfaces, June 7-10, vol. 1, pp (2004) 7. Naedele, M.: Standards for XML and Web services security. Computer 36(4), (2003) 8. Woodman, S., Morgan, G., Parkin, S.: Portal replication for Web application availability via SOAP. In: Proceedings of the Eighth International Workshop on Object-Oriented Real-Time Dependable Systems (WORDS 2003), January 15-17, pp (2003) 9. Yang, C.S., Liu, C.Y., Chen, J.H., Sung, C.Y.: Design and Implementation of Secure Web-based LDAP Management System. In: Proceedings, 15th International Conference on Information Networking, January 31-February 2, pp (2001)