【作者】 周素华；

【导师】 欧阳丹彤；

【作者基本信息】 吉林大学 ， 计算机软件与理论， 2008， 硕士

【摘要】 本文首先简要说明了Web Service的应用背景,介绍了Web Service的概念、体系结构及Web Service的相关协议,指出了其跨平台的重要特性,在当前有着广泛的应用。为了解决电子政务中的“信息孤岛”问题,我们开发了基于Web Service的数据交换系统,并对其进行了升级完善,成为独立的产品,可以在政务项目中加以应用。本文从数据交换的现状和需求出发,详细介绍了数据交换系统的总体设计思想和体系架构,阐明了需要解决的关键问题,以及系统中对安全性的保证。更多还原

【Abstract】 With the development of Internet and Web technology, the projects of Web-based rise rapidly. However, there are still some problems in the traditional Web development: over-centralized control; closed system, tightly coupled; various platform incompatibilities. In the building of e-government projects, these problems have resulted in the emergence of“information islands”.In the audit requirement of online platform in JiLin ZhengWu DaTing, the district halls can not do the unified online approval because they have their own information-processing systems. They have to repeat the same information and reduce the efficiency. So a large number of information can not fully play its role. In order to solve the problem, I have the paper. In the basis of Web Service research, we develop the system of data-exchange, solved the problem of“information islands”and shared the data. From the requirement of the system, we establish the system of data-exchange in basis of Web Service. The system is a data-exchange platform that is based on the PKI, Axis, XML, SOAP, TCP/IP technology and accords with the Internet standard agreement. It is easy-expansion, cross-platform, cross-firewall, flexible, and applicable to exchange the information in heterogeneous system.The requirement of the data-exchange system includes the following four aspects: sending function, transmitting function, receiving function and system maintenance. Sending function of the system means that data-extraction, data-packing, data-signature, data-sending, log-recording. Transmitting function of the system involves in the receipt of data-receiving, extracting summary data, data verification-signature, the next node of the data-transmitting, transmitted data-signatures, transmitted data-repackaging, log-recording of transmitting process. Receiving function of the system includes data-receiving, data-unpackaging, signature verification, sending information after receiving data, log-recording of receiving process. The requirement of system maintenance in the data-exchange system includes the maintenance of exchange-domain and the maintenance of exchange-router. It is the maintenance of all those involved in the exchange system, for example, the unified code, the Chinese name, the corresponding url, description, and so on. It must ensure that the code is only in the entire system within the exchange. Exchange-router refers to the selection of router when the exchange-data goes to the destination in the data-exchange system (intermediate transceiver nodes).We introduce the design mentality and architecture of the data-exchange system in detail. This paper analyses the key problem of the data-exchange system is standard and concentrate. For this, we explain the principle of the system in two areas: Data Construction, identification and analysis; sending and receiving data. In order to identify and parse datas, the application systems consult with the data format and form the XML or binary stream format to structure the data packets. When the receiver in the system gets the data packets, they will verify whether the data packets are the right format, and they will discard packets if the packets do not meet the requirements. At the same time, the receiver will tell the sender the thing about this.In the process of sending and receiving data, we divide the data-exchange system into two parts: data-exchange platform and data-exchange plug-in. Data-exchange platform is used to storage and transmit the data and deployed in the server. Data-exchange plug-in deployed in the client is used to send data to the server and fetch data from the server-side. We can set several data-exchange platforms and send data to different departments (server-side).For the data-exchange system in Web Service-based, the security is the top priority in development. The objects of the system include personal, corporate, government, and the system connects to the Internet, so it must be security assurances to protect the confidential information of government or enterprises. The system uses digital certificates based on PKI Certification Center and digital signature technology to ensure the security. The way of sending and receiving data in packets ensures that the data is non-explicit transmission. At the same time, the data packets must have the digital signatures. The receiver will verify the data packets, identify as the right data, and then deal with them. In addition, the data-exchange platform has a visa system to ensure that the applications use their own certificates so as to ensure the security. Data-exchange system is a Web project after all, so it has some sensitive configuration files for the flexibility of the system. We place these files in the WEN-INF folder and they can not be visited through external URL. The key information is hidden.On the basis of security, the system which uses Axis engine to develop Web Service project is easy to deploy and convenient for the project personnel operation. At the same time, the system has the characteristics of open, flexibility and stability.The open character performs in the open of exchange-domain and the open of exchange-data format. The system communicates by the way of SOAP and uses XML as the data-descriptor, so the system is platform-independent, unrelated to the development of the language. If there is a new application to join the system, we only need to expand the functions of the exchange system without any changes to the original system. At the same time, the different data formats in the data-exchange system are dealt with a unified model of the factory. We only need a unified data format in the application. Flexible character performs in the simple and flexible of the exchange information configuration. We only need the modification of the corresponding configuration files, instead of redeploying the exchange plug-ins. Addition, the system is Loosely Coupled System. If an application system is over for some reason, it will only affect this application and the entire domain of any other exchange systems will not be affected. So we can say that the system is steady.The data-exchange system based on Web Service can meet the business needs of users and the security makes users relax. Today, the system has been used in several e-government projects, such as the BaiCheng City People’s Government and SiChuan Province county-town project. Practice has proved that this system can connect the original administrative system for the information exchange between systems, and remove information islands. So the system has broad application prospects.更多还原