Research Of Real-Time Data Accessing Technology Based On Web Services

With the rapid development of the Internet,Distributed ComputingModel based on Web Services becomes the trend of development ofsoftware technology and applications. Web Services provides a newparadigm for Distributed Computing. Web Services technology is an openInternet Protocol-oriented software application. It completes the interactionwith other application software by XML messages and protocols to realizethe interconnection and interoperability of the systems in the greater scope.In the process of developing information technology, informationintegration becomes the major trend of the enterprise development. How tointegrate the real-time data of heterogeneous platforms, form the uniformreal-time database and transmit to the whole enterprise and superiordepartment by LAN and WAN to realize the real network management isthe main problem to be solved of industrial enterprise. Most of theinformation integration schemes of enterprise use the traditionalmiddleware technology. The tightly coupled mechanism which they usemakes the system has limited flexibility, connectivity andextensibility.Web Services is a new distributed object technology, which iswell-encapsulated, loosely coupled and highly integrated, so it can satisfythe dynamic need of the members of enterprise and solve the problem ofheterogeneous architecture. This makes the application integrationenvironment have well-extensibility and easy to maintain. Real-time dataaccessing technology based on Web Services which using the softwaredesign method of SOA can converse the real-time data informationgathered from the industry scene to Web Services, and it provides real-timedata accessing service for ERP or PDM. Service request can access thereal-time database by B/S.Currently, real-time services based on the Web Services frameworkare still unable to fully meet the Enterprise Information Integration.The paper analyzes the Web Services performance and then optimizes theperformance Web Services to improve the real-time services.There arethree factors affecting the response time of Web Services: the networktransmission time, the information processing time and the service deliverytime.In the phase of transmissing, compressing XML files can shorten thetransmission time, so the paper proposes the method of compressing SOAPmessages and model compression.In the phase of message processing,XML parsing, deserialization and serialization are the mosttime-comsumed phases. They are also the bottlenecks of Web Servicesperformance, particularly while the effective load increasing. To improvethe performance of Web Services, we must optimize the process of XMLoptimization analysis, Deserialization, Serialization.This article introduces the VTD-XM Parser and analyzes thecharacteristics of DOM, SAX and VTD-XML. VTD-XML cam meet theneed of real-time better on speed and performance.According to thecharacteristics of industrial real-time data access and the principle ofVTD-XML parser, the paper designs the template VTD-XML cache toimprove the speed of parsing XML documents. This method generates aonly template ID for every SOAP message using MD5, and manages thetemplate cache by using API provided by VTD-XML. The result showsthat VTD-XML template cache can improve the performance of WebServices and meets the need of real-time data access services. Finally thepaper realizes the real-time data access services based on Web Servicesusing Weblogic of BEA under J2EE, and configures the VTD-XML parsertemplate cache to enable the real-time data access services to meet thereal-time needs of users, computers and other systems of enterprise, such asERP, PDM and CRM, etc.