- 匿名使用者2 0 年前最佳解答
Nowadays, as the market emerges on the Internet, a huge number of businesses are shifting their focus to the customers on the Internet, intending to grab a large market share. However, compared to the traditional channels, the Internet exhibits several challenges. In the Internet environment, many businesses need to provide their services to their customers. However, many legacy applications cannot be accessed through the prevailing web browsers over the standard HTTP. As a result, businesses need a mechanism to effectively expose many existing applications to their customers through World Wide Web.Secondly, most businesses focus on their core activities and cooperate with other businesses to obtain other required services, so as to meet customers’ requests. However, existing inter-business electronic systems, mostly following Electronic Data Interchange (EDI) standard, are implemented with proprietary data formats and communication protocols. Nevertheless, in today’s dynamic environment, businesses are very likely to change their partners for the purpose of reducing costs or improving product quality, which will in turn incur much cost resulted from incompatible systems or applications. Hence it is imperative that businesses need an architecture that supports loosely integration of heterogeneous applications, which will lower the cost of system integration and thus make businesses more competitive.The above business needs drive the emergence of the Web services technologies that aim to gracefully solve these problems.1.The Web services describe their service interface through a standard XML-based language WSDL (Web Service Description Language) [WSDL]. Therefore, the operations provided by a Web service are easily publized.2.The Web services technologies include a protocol called SOAP (Simple Object Access Protocol) [SOAP] that can help exchange XML-based messages over HTTP either in a synchronous RPC or asynchronous way. With the help of this protocol, a client application can invoke any application encapsulated as a Web Service in a standard message format without modifying the logic for processing the message. Before one can invoke a Web service, there must be a mechanism for service providers to register their Web services and service consumers to discover the suitable Web services. Thus Web services architecture also supports the registry and discovery of Web services by a central registry called UDDI (Universal Description, Discovery, and Integration) [UDDI] registry, which is an implementation of UDDI specification. UDDI registry is a registry service that catalogs companies and their Web services, and thus anyone including business applications or humans can query the UDDI registry to find a suitable service to cooperate with.
2005-10-20 07:29:57 補充：